US20100240382A1 - Systems, apparatus and methods for interference management in wireless networks - Google Patents

Abstract

Systems, apparatus, methods and computer program products are provided. In some embodiments, a method for facilitating interference management in an unplanned wireless communication system is provided. The method can include a non-serving base station: determining information about a user equipment, wherein the user equipment is served by a serving base station; and employing determined information about the user equipment to perform interference management at a non-serving base station. The method can also include the non-serving base station synchronizing to the user equipment using information indicative of the uplink scrambling code for use by the user equipment and information indicative of uplink slot configurations being used by the user equipment. The method can also include the non-serving base station performing interference management on the user equipment served by the serving base station.

Description

CLAIM OF PRIORITY
• This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/161,643, titled “Network Listen for Interference Management for Home Node/eNode Base Stations,” which was filed Mar. 19, 2009, and the entire contents of which are incorporated herein by reference.
CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is related to concurrently filed and commonly owned U.S. patent application Ser. No. ______, entitled “SYSTEMS, APPARATUS AND METHODS FOR INTERFERENCE MANAGEMENT IN WIRELESS NETWORKS,” and assigned Attorney Docket No. 091633U1; and U.S. patent application Ser. No. ______ entitled, “SYSTEMS, APPARATUS AND METHODS FOR INTERFERENCE MANAGEMENT IN WIRELESS NETWORKS,” and assigned Attorney Docket No. 091633U3, the disclosures of which are hereby incorporated herein.
BACKGROUND
• I. Field
• The following description relates to wireless communications, in general, and to interference management in unplanned wireless communication systems, in particular.
• II. Background
• Wireless communication systems are widely deployed to provide various types of communication. For instance, voice and/or data can be provided via such wireless communication systems. A typical wireless communication system, or network, can provide multiple users access to one or more shared resources (e.g., bandwidth, transmit power). For instance, a system can use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing (OFDM), and others.
• Generally, wireless multiple access communication systems can simultaneously support communication for multiple user equipment (UEs). Each UE can communicate with one or more base stations (BSs) via transmissions on forward and reverse links. The forward link (or downlink (DL)) refers to the communication link from BSs to UEs, and the reverse link (or uplink (UL)) refers to the communication link from UEs to BSs.
• In addition to conventional wireless multiple access communication systems, a new class of wireless multiple access communication systems employing BSs that cover small cell areas has emerged. These BSs can be installed in a home of a user and can provide indoor wireless coverage to UEs in or in geographic proximity to the home. Such personal miniature BS can be Femto BSs, Femto cells, Home Node B (HNB), Home eNode B (HeNB), or the like.
• The BSs can operate according to restricted association, or closed subscriber group (CSG), methods whereby the owner of the home BS can determine which UEs are allowed to associate with the home BS. This is similar to, for example, 802.11 access points, wherein the wired equivalent privacy (WEP)/Wi-Fi protected access (WPA) key or explicit media access control (MAC) address provisioning can allow the owner of the access point to control access. Accordingly, UEs that are in geographic proximity to a BS, and have a radio link quality that would allow communication with the BS, could be prevented from such communication if the UE is not associated with the BS and/or within the subscriber group for the BS. The UEs can nonetheless cause interference to the BS when the UE transmits on the UL. Similarly, the UE is more susceptible to interference from the BS when the BS transmits on the DL to UEs with which the BS is associated. Accordingly, systems, apparatus and methods for interference management are desired.
SUMMARY
• The following presents a simplified summary of one or more embodiments in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of all contemplated embodiments, and is intended to neither identify key or critical elements of all embodiments nor delineate the scope of any or all embodiments. Its sole purpose is to present some concepts of one or more embodiments in a simplified form as a prelude to the more detailed description that is presented later.
• In accordance with one or more embodiments and corresponding disclosure thereof, various aspects are described in connection with interference management in wireless communication systems.
• According to related aspects, a method is provided. The method can include: obtaining information about a UE served by a serving BS; and determining signal information based, at least, in part, on the information.
• In another aspect, a computer program product including a computer-readable medium is provided. The computer program product can include: a first set of codes for causing a computer to obtain information about a UE served by a serving BS; and a second set of codes for causing the computer to determine signal information based, at least, in part, on the information, wherein a non-serving BS includes the computer.
• According to another aspect, an apparatus is provided. The apparatus can include means for obtaining information about a UE served by a serving BS; and means for determining signal information based, at least, in part, on the information.
• According to another aspect, another apparatus is provided. The apparatus can include obtain information about a UE served by a serving BS; and determine signal information based, at least, in part, on the information.
• In another aspect, another method is provided. The method can include: determining information about a UE, wherein the UE is served by a serving BS; and employing determined information about the UE to perform interference management at a non-serving BS.
• In another aspect, a computer program product including a computer-readable medium is provided. The computer program product can include a computer-readable medium, comprising: a first set of codes for causing a computer to determine information about a UE, wherein the UE is served by a serving BS; and a second set of codes for causing a computer to employ determined information about the UE to perform interference management at the computer, wherein a non-serving BS includes the computer.
• In another aspect, another apparatus is provided. The apparatus can include: means for determining information about a UE, wherein the UE is served by a serving BS; and means for employing determined information about the UE to perform interference management at the apparatus.
• In another aspect, another apparatus is provided. The apparatus can include a non-serving BS configured to: determine information about a UE, wherein the UE is served by a serving BS; and employ determined information about the UE to perform interference management at the non-serving BS.
• In another aspect, another method is provided. The method can include: synchronizing aBS604 downlink subframe to aBS602 downlink subframe, wherein theBS602 downlink subframe is transmitted from a serving BS to a UE served by the serving BS; decoding one or more control channel symbols of theBS602 downlink subframe, wherein gating of one or more data channel symbols of theBS604 downlink subframe is performed prior to the decoding; and determining information for performing interference management associated with the UE, wherein determining information is based, at least, in part, on the decoding one or more symbols of theBS602 downlink subframe.
• In another aspect, a computer program product including a computer-readable medium is provided. The computer program product can include a computer-readable medium, comprising: a first set of codes for causing a computer to synchronize aBS604 downlink subframe to aBS602 downlink subframe, wherein theBS602 downlink subframe is transmitted from a serving BS to a UE served by the serving BS; a second set of codes for causing the computer to decode one or more control channel symbols of theBS602 downlink subframe, wherein gating of one or more data channel symbols of theBS604 downlink subframe is performed prior to the decoding; and a third set of codes for causing the computer to determine information for performing interference management associated with the UE, wherein determining information is based, at least, in part, on decoding one or more symbols of theBS602 downlink subframe.
• In another aspect, another apparatus is provided. The apparatus can include: means for synchronizing aBS604 downlink subframe to aBS602 downlink subframe, wherein theBS602 downlink subframe is transmitted from a serving BS to a UE served by the serving BS; means for decoding one or more control channel symbols of theBS602 downlink subframe, wherein gating of one or more data channel symbols of theBS604 downlink subframe is performed prior to the decoding; and means for determining information for performing interference management associated with the UE, wherein determining information is based, at least, in part, on the decoding one or more symbols of theBS602 downlink subframe.
• In another aspect, another apparatus is provided. The apparatus can include a non-serving BS configured to: synchronize aBS604 downlink subframe to aBS602 downlink subframe, wherein theBS602 downlink subframe is transmitted from a serving BS to a UE served by the serving BS; decode one or more control channel symbols of theBS602 downlink subframe, wherein gating of one or more data channel symbols of theBS604 downlink subframe is performed prior to the decoding; and determine information for performing interference management associated with the UE, wherein determining information is based, at least, in part, on decoding one or more symbols of theBS602 downlink subframe.
• Toward the accomplishment of the foregoing and related ends, the one or more embodiments comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth herein detail certain illustrative aspects of the one or more embodiments. These aspects are indicative, however, of but a few of the various ways in which the principles of various embodiments can be employed and the described embodiments are intended to include all such aspects and their equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is an illustration of an example wireless communication in accordance with various aspects set forth herein.
• FIG. 2 is an illustration of another example wireless communication system in accordance with various aspects set forth herein.
• FIG. 3 is an illustration of an example wireless communication system where one or more Femto nodes are deployed in accordance with various aspects set forth herein.
• FIG. 4 is an illustration of an example coverage map in a wireless communication system in accordance with various aspects set forth herein.
• FIGS. 5 and 6A are illustrations of example block diagrams of a wireless communication system for facilitating interference management in accordance with various aspects set forth herein.
• FIG. 6B is an illustration of a flowchart of a method for facilitating interference management in accordance with various aspects set forth herein.
• FIG. 7 illustrates example downlink and uplink timelines for facilitating interference management in accordance with various aspects set forth herein.
• FIGS. 8A and 8B are illustrations of flowcharts of methods for facilitating interference management in accordance with various aspects set forth herein.
• FIG. 9 is a block diagram of example subframe structures for normal and extended cyclic prefix for facilitating interference management in accordance with various aspects set forth herein.
• FIGS. 10,11 and12 are illustrations of flowcharts of methods for facilitating interference management in accordance with various aspects set forth herein.
• FIGS. 13-18 are illustrations of block diagrams of example systems for facilitating interference management in accordance with various aspects set forth herein.
• FIG. 19 shows an example wireless communication system in which the embodiments described herein can be employed in accordance with various aspects set forth herein.
DETAILED DESCRIPTION
• Various embodiments are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident, however, that such embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more embodiments.
• As used in this application, the terms “component,” “module,” “system,” and the like are intended to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, software and/or software in execution. For example, a component can be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and/or the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component can be localized on one computer and/or distributed between one or more computers. In addition, these components can execute from various computer-readable media having various data structures stored thereon. The components can communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network such as the Internet with other systems by way of the signal).
• The techniques described herein can be used for various wireless communication systems such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier-frequency division multiple access (SC-FDMA) and/or other systems. The terms “system” and “network” are often used interchangeably. A CDMA system can implement a radio technology such as Universal Terrestrial Radio Access (UTRA), CDMA8020, etc. UTRA includes Wideband-CDMA (W-CDMA) and other variants of CDMA. CDMA8020 covers interim standard 8020 (IS-8020), interim standard 95 (IS-95) and interim standard 856 (IS-856). An OFDMA system can implement a radio technology such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS). 3GPP Long Term Evolution (LTE) is an upcoming release of UMTS that uses E-UTRA, which employs OFDMA on the downlink and SC-FDMA on the UL. UTRA, E-UTRA, UMTS, LTE and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP). Additionally, CDMA8020 and UMB are described in documents from an organization named “3rdGeneration Partnership Project 2” (3GPP2). Further, such wireless communication systems can additionally include peer-to-peer (e.g., mobile-to-mobile) ad hoc network systems often using unpaired unlicensed spectrums, 802.xx wireless local area network (wireless LAN), BLUETOOTH and any other short- or long-range, wireless communication techniques.
• SC-FDMA utilizes single carrier modulation and frequency domain equalization. SC-FDMA can have similar performance and essentially the same overall complexity as those of an OFDMA system. A SC-FDMA signal can have lower peak-to-average power ratio (PAPR) because of its inherent single carrier structure. SC-FDMA can be used, for instance, in UL communications where lower PAPR greatly benefits UEs in terms of transmit power efficiency. Accordingly, SC-FDMA is implemented as an UL multiple access scheme in 3GPP Long Term Evolution (LTE) or Evolved UTRA.
• Furthermore, various embodiments are described herein in connection with UEs. A UE can also be called a system, subscriber unit, subscriber station, mobile station, mobile, remote station, remote terminal, mobile device, access terminal, wireless communication device, user agent or user device. A UE can be a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device having wireless connection capability, computing device, or other processing device connected to a wireless modem. Moreover, various embodiments are described herein in connection with a BS or access node (AN). A BS can be utilized for communicating with UEs and can also be referred to as an access point, BS, Femto node, Pico Node, Node B, Evolved Node B (eNodeB, eNB) or some other terminology.
• Moreover, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from the context, the phrase “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from the context to be directed to a singular form.
• Various aspects or features described herein can be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term “article of manufacture” as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include, but are not limited to, magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips), optical disks (e.g., compact disk (CD), digital versatile disk (DVD)), smart cards, and flash memory devices (e.g., erasable programmable read only memory (EPROM), card, stick, key drive). Additionally, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term “machine-readable medium” can include, without being limited to, wireless channels and various other media (and/or storage media) capable of storing, containing, and/or carrying codes and/or instruction(s) and/or data.
• In some aspects the teachings herein may be employed in a network that includes macro scale coverage (e.g., a large area cellular network such as a 3G networks, typically referred to as a macro cell network) and smaller scale coverage (e.g., a residence-based or building-based network environment). A UE moves through such a network. The UE may be served in certain locations by BSs that provide macro coverage while the UE may be served at other locations by BSs that provide smaller scale coverage. In some aspects, the smaller coverage nodes may be used to provide incremental capacity growth, in-building coverage, and different services (e.g., for a more robust user experience). In the discussion herein, a node that provides coverage over a relatively large area may be referred to as a Macro node. A node that provides coverage over a relatively small area (e.g., a residence) may be referred to as a Femto node. A node that provides coverage over an area that is smaller than a macro area and larger than a Femto area may be referred to as a Pico node (e.g., providing coverage within a commercial building).
• A cell associated with a Macro node, a Femto node, or a Pico node may be referred to as a macro cell, a Femto cell, or a Pico cell, respectively. In some implementations, each cell may be further associated with (e.g., divided into) one or more sectors.
• In various applications, other terminology may be used to reference a Macro node, a Femto node, or a Pico node. For example, a Macro node may be configured or referred to as a BS, access point, eNodeB, macro cell, and so on. Also, a Femto node may be configured or referred to as a Home NodeB, Home eNodeB, access point access node, a BS, a Femto cell, and so on.
• FIG. 1 is an illustration of an example wireless communication system in accordance with various aspects set forth herein. Inwireless communication system100, interference caused by transmissions on the UL can be managed by theBS102.
• Referring now toFIG. 1, awireless communication system100 is illustrated in accordance with various embodiments presented herein.Wireless communication system100 includes aBS102 that can include multiple antenna groups. For example, one antenna group can includeantennas104,106, another group can compriseantennas108,110, and an additional group can includeantennas112,114. Two antennas are illustrated for each antenna group; however, more or fewer antennas can be utilized for each group.BS102 can additionally include a transmitting node chain and a receiving node chain, each of which can in turn comprise a plurality of components associated with signal transmission and reception (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, antennas), as will be appreciated by one skilled in the art.BS102 can communicate with one or more UEs such asUE116,122. However, it is to be appreciated thatBS102 can communicate with substantially any number of UEs similar toUEs116,122.UEs116,122 can be, for example, cellular phones, smart phones, laptops, handheld communication devices, handheld computing devices, satellite radios, global positioning systems, PDAs, and/or any other suitable device for communicating overwireless communication system100. As depicted,UE116 is in communication withantennas112,114, whereantennas112,114 transmit information toUE116 overDL118 and receive information fromUE116 over aUL120. Moreover,UE122 is in communication withantennas104,106, whereantennas104,106 transmit information toUE122 over aDL124 and receive information fromUE122 over aUL126. In a frequency division duplex (FDD) system,DL118 can utilize a different frequency band than that used byUL120, andDL124 can employ a different frequency band than that employed byUL126, for example. Further, in a time division duplex (TDD) system,DL118 andUL120 can utilize a common frequency band andDL124 andUL126 can utilize a common frequency band.
• Each group of antennas and/or the area in which they are designated to communicate can be referred to as a sector ofBS102. For example, antenna groups can be designed to communicate to UEs in a sector of the areas covered byBS102. In communication overDLs118,124, the transmitting antennas ofBS102 can utilize beamforming to improve signal-to-noise ratio ofDLs118,124 forUEs116,122. Also, whileBS102 utilizes beamforming to transmit toUEs116,122 scattered randomly through an associated coverage,UEs116,122 in neighboring cells can be subject to less interference as compared to a BS transmitting through a single antenna to all its UEs.
• FIG. 2 is an illustration of another example wireless communication system in accordance with various aspects set forth herein. Thewireless communication system200 provides communication for multiple cells, such as, for example, macro cells202a-202g, with each cell being serviced by a corresponding BS (e.g., BSs204a-204g). As shown inFIG. 2, UEs (e.g., UEs206a-206l) can be dispersed at various locations throughout the system over time. Each of the UE206 can communicate with one or more BSs204a-204gon a DL or an UL at a given moment, depending upon whether the UE206 is active and whether it is in soft handover, for example. Thewireless communication system200 may provide service over a large geographic region. For example, macro cells202a-202gmay cover a few blocks in a neighborhood.
• FIG. 3 is an illustration of an example wireless communication system where one or more Femto nodes are deployed in accordance with various aspects set forth herein. Specifically, thewireless communication system300 includes multiple Femto nodes (e.g., Femto nodes310A and310B) installed in a relatively small scale network environment (e.g., in one or more user residences330). One or more of the Femto nodes310A,310B can be coupled to a wide area network340 (e.g., the Internet) and a mobileoperator core network350 via a digital subscriber line (DSL) router, a cable modem, a wireless link, or other connectivity means (not shown). As will be discussed below, the Femto nodes310A,310B can be configured to serve associated UEs (e.g.,UE320A) and, optionally, alien UEs (e.g.,UE320B). For example, access to one or more Femto nodes310A,310B may be restricted whereby one of theUEs320A,320B can be served by one or more Femto nodes310A,310B that are designated for theUEs320A,320B (e.g., a home Femto node) but cannot be served by any Femto nodes310A,310B that are not designated for theUEs320A,320B (e.g., a neighbor's Femto node).
• However, in various embodiments, an associatedUE320A can experience interference on the DL from a Femto node310A serving analien UE320B. Similarly, a Femto node310B associated with associatedUE320A can experience interference on the UL from thealien UE320B. In embodiments, interference management can be facilitated in thewireless communication system300 as described herein.
• FIG. 4 is an illustration of an example coverage map in a wireless communication system providing configuration of scheduling policy for facilitating distributed scheduling in accordance with various aspects set forth herein. Thecoverage map400 can includetracking areas402A,402B,402C (or routing areas or location areas), each of which can include several macro coverage areas. In the embodiment shown, areas of coverage associated with trackingareas402A,402B,402C are delineated by the wide lines and themacro coverage areas404A,404B are represented by the hexagons. Thetracking areas402A,402B,402C can includeFemto coverage areas406A,406B,406C. In this example, each of theFemto coverage areas406A,406B,406C is depicted within amacro coverage area404A,404B,404C. It should be appreciated, however, that aFemto coverage area406A,406B,406C may not lie entirely within amacro coverage area404A,404B,404C. In practice, a large number ofFemto coverage areas406A,406B,406C can be defined with a giventracking area402A,402B,402C ormacro coverage area404A,404B. Also, one or more Pico coverage areas (not shown) can be defined within atracking area402A,402B,402C ormacro coverage area404A,404B,404C.
• Referring again toFIG. 3, the owner of a Femto node310A can subscribe to mobile service, such as, for example, 3G mobile service, offered through the mobileoperator core network350. In addition, a UE320 may be capable of operating both in macro environments and in smaller scale (e.g., residential) network environments. In other words, depending on the current location of the UE320, the UE320 may be served by a macrocell access node360 of the mobileoperator core network350 or by any one of a set of Femto nodes310 (e.g., the Femto nodes310A and310B that reside within a corresponding user residence330). For example, when a subscriber is outside his home, he is served by a standard macrocell access node360 and when the subscriber is at home, he is served by Femto node310A. Here, it should be appreciated that a Femto node310 may be backward compatible with UEs320 that are existing at the time of manufacture and/or design of the Femto node310.
• A Femto node310 may be deployed on a single frequency or, in the alternative, on multiple frequencies. Depending on the particular configuration, the single frequency or one or more of the multiple frequencies can overlap with one or more frequencies used by the macrocell access node360.
• In some aspects, a UE320 can be configured to connect to a preferred Femto node (e.g., the home Femto node of the UE320) whenever such connectivity is possible. For example, whenever the UE320 is within theuser residence330, it may be desired that the UE320 communicate only with the Femto node310 in the user residence.
• In some aspects, if the UE320 operates within the mobileoperator core network350 but is not residing on its most preferred network (e.g., as defined in a preferred roaming list), the UE320 may continue to search for the most preferred network (e.g., the preferred Femto node310) using a Better System Reselection (BSR), which can involve a periodic scanning of available systems to determine whether better systems are currently available, and subsequent efforts to associate with such preferred systems. With the acquisition entry, the UE320 may limit the search for specific band and channel. For example, the search for the most preferred system may be repeated periodically. Upon discovery of a preferred Femto node310, the UE320 selects the Femto node310 for camping within its coverage area.
• A Femto node may be restricted in some aspects. For example, a given Femto node may only provide certain services to certain UEs. In deployments with so-called restricted (or closed) association, a given UE may only be served by the macro cell mobile network and a defined set of Femto nodes (e.g., the Femto nodes310 that reside within the corresponding user residence330). In some implementations, a node may be restricted to not provide, for at least one node, at least one of: signaling, data access, registration, paging, or service.
• In some aspects, a restricted Femto node (which may also be referred to as a CSG Home NodeB) is one that provides service to a restricted provisioned set of UEs. This set may be temporarily or permanently extended as necessary. A channel on which all Femto nodes (or all restricted Femto nodes) in a region operate may be referred to as a Femto channel.
• Various relationships may thus exist between a given Femto node and a given UE. For example, from the perspective of a UE, an open Femto node may refer to a Femto node with no restricted association. A restricted Femto node may refer to a Femto node that is restricted in some manner (e.g., restricted for association and/or registration). A home Femto node may refer to a Femto node on which the UE is authorized to access and operate on. A guest Femto node may refer to a Femto node on which a UE is temporarily authorized to access or operate on. An alien Femto node may refer to a Femto node on which the UE is not authorized to access or operate on, except for perhaps emergency situations (e.g., 911 calls).
• From a restricted Femto node perspective, a home UE may refer to a UE that authorized to access the restricted Femto node. A guest UE may refer to a UE with temporary access to the restricted Femto node. An alien UE may refer to a UE that does not have permission to access the restricted Femto node, except for perhaps emergency situations, for example, such as 911 calls (e.g., a UE that does not have the credentials or permission to register with the restricted Femto node).
• While the description ofFIG. 4 has been provided with reference to a Femto node, it should be appreciated, that a Pico node may provide the same or similar functionality for a larger coverage area. For example, a Pico node may be restricted, a home Pico node may be defined for a given UE, and so on.
• FIG. 5 is an illustration of an example block diagram of a wireless communication system for facilitating interference management in accordance with various aspects set forth herein.
• Thewireless communication system500 can include one or more BSs502,503 in respective cells ofwireless communication system500, and at least one BS configured to perform one or more of the network listening and/or interference management methods described herein. In some embodiments, one or more ofBSs502,503 can be Femto access nodes configured to provide communication to and from a UE in the Femto cell managed by the Femto access node. For example, the Femto access nodes can be Femto Node Bs. By way of example, but not limitation, in various embodiments, the Femto node Bs can be UMTS HNBs or LTE HeNB.
• In some embodiments, theBSs502,503 can be BSs located in one or more different Femto cells. Theinterference management modules512,519 can cause theBSs502,503 to perform one or more network listening methods and/or interference management methods described herein. In one or more embodiments, interference management, as discussed in greater detail below, can include, but is not limited to, interference avoidance, power control, cancellation of soft symbols, cancellation of symbols mapped to constellation points, full cancellation (which can include decoding and canceling), treating highly interfered symbols as erasures, and any other interference mitigation technique.
• TheBSs502,503 can includeprocessors514,521.Processors521,514 can be configured to perform one or more of the network listening functions and/or interference management functions described herein with reference to any of the systems, methods, apparatus and/or computer program products. In various embodiments, theprocessors521,514 can be implemented as hardware and/or software.
• TheBSs502,503 can includememory523,516. Thememory523,516 can be for storing computer-executable instructions and/or information for performing the functions described herein with reference to any of the systems, methods, apparatus and/or computer program products.
• TheBSs502,503 can includetransceivers510,530.Transceivers510,530 can be configured to transmit and/or receive signaling information, configuration information, control information, data and/or any other information generated or received to employ network listening for interference management as described herein.
• Thewireless communication system500 can also include one ormore UEs508,506 in respective cells ofwireless communication system500. At least one of the one ormore UEs508,506 can be located near a Femto cell of a BS to which the UE is not associated but to which the UE causes interference. For example,UE508 can be located within geographic proximity toBS502.UE508 can be serviced byBS503 but cause interference toBS502 when theUE508 is in close geographic proximity toBS502. As such,BS502 can employ network listening methods for facilitating management of the interference caused byUE508.
• In various embodiments, theUEs508,506 can be UEs serviced by UMTS HNBs or LTE HeNBs and/orUEs508,506 in UMTS or LTE systems.
• TheUEs508,506 can includeprocessors522,515.Processors522,515 can be configured to perform coordination information signaling and/or data or control information processing, transmission and/or reception. In various embodiments, coordination information signaling can be used for handover purposes and for numerous other purposes other than handover. In various embodiments, coordination signaling can include, but is not limited to, handover signaling or any type of signaling for coordinating communications between theBSs502,503. Generally, the systems, methods, apparatus and/or computer program products described herein can employ network listening and/or interference management.
• TheUEs508,506 can includememory524,517. Thememory524,517 can be for storing computer-executable instructions and/or information for performing the functions described herein with reference to any of the systems, methods, apparatus and/or computer program products.
• TheUEs508,506 can includetransceivers518,511.Transceivers518,511 can be configured to transmit and/or receive coordination information signaling, including, but not limited to handover signaling, and/or any other a number of other types of data or control information.
• FIG. 6A illustrates another block diagram of an example system for facilitating interference management in a wireless network.BSs602 and604 can communicate with a UE606 (or other wireless devices) to provide network access thereto. In one example, theUE606 can receive wireless network access from theBS602, and theBS604 can be a restricted association BS that is inaccessible by theUE606. TheBS602 can include ameasurement receiving module608 that can receive a BS measurement and a coordinationinformation signaling module610 that can transmit coordination information signaling to a BS based, at least, in part on the measurement. TheUE606 can comprise aBS measuring module612 that can conduct the measurement of the BS.
• BS604 can comprise a coordination information signalingreceiving module614 that can obtain coordination information signaling from one or more BSs or related devices, asymbol gating module616 that can gate one or more symbols transmitted from theBS604 to enable theBS604 to listen to transmissions between theBS602 and theUE606. TheBS604 can listen for and/or determine information related to UL assignments associated with theUE606, for example. TheBS604 can also include a fast timescale information module618 and a slow timescale information module622 that can receive, obtain or derive information about theUE606 for performing interference management, as discussed in greater detail below. TheBS604 can also include aninterference management module620 that can cancel or avoid interference or perform any number of other reception or other techniques for mitigating the effects of the interference from theUE606.
• In one example, theBS measuring module612 can measure information transmitted fromBS604 to determine a signal strength, for example, or other measurement. TheUE606 can transmit the measurement to theBS602, which can be received by themeasurement receiving module608. Based on the measurement, the coordinationinformation signaling module610 can determine whether to transmit coordination information signaling to theBS604.
• The coordination information signaling can comprise one or more parameters (e.g., slow time scale information) related to theUE606. For example, in UMTS systems, the slow time scale information can include, but is not limited to, a scrambling code used by theUE606, and/or configuration of UL channels (e.g., UL dedicated physical channel (DPCH), enhanced dedicated physical channel (E-DPCH)). As another example, for LTE system, the slow time scale information can include a cell radio network temporary identifier (C-RNTI), persistent assignment information (e.g., resource blocks (RBs), periodicity modulation, code rate, and/or hopping) and/or physical channel configuration information (e.g., for a physical uplink control channel (PUCCH), physical uplink shared channel (PUSCH), sounding reference signal (SRS)). In some embodiments, the C-RNTI can be a 16-bit identifier assigned to theUE606 by theBS602. The coordination information signalingreceiving module614 and/or the slow timescale information module622 can obtain the coordination information signaling from theBS602 and determine the slow time scale information.
• The slow time scale information exchange can be performed using the existing measurement, measurement reporting and/or existing or new coordination information signaling mechanisms in some embodiments. In some embodiments, the slow time scale information exchange can be performed by augmenting handover messages as outlined and/or in response to the messages.
• In UMTS systems,UE606 can be served by a macro Node B, which can beBS602.UE606 can make DL measurements onBS604 and report (either periodically or in an event-based fashion) toBS602.BS602 can process the reports and apply a coordination information algorithm to trigger signaling betweenBS602 andBS604. For example, in one embodiment, the signaling can include, but is not limited to, soft handover signaling. In particular, in some embodiments, over the Iub and/or Iur interfaces, a RadioLinkSetupRequest/Response message can be transmitted. The message can contain information pertaining to theUE606 that has requested an Active Set Add. Although, theBS604 will not add theUE606 upon receiving the RadioLinkSetupRequest message from theBS602, theBS604 will have the information necessary to detect and, for example, cancel or avoid the signal ofUE606 and/or conduct power control to otherwise combat the effects of interference from theUE606. For example, the RadioLinkSetupRequest/Response message, the Active Set Add message and the RadioLinkSetupRequest message can be as specified in the 3GPP TS 25.423 specification and the 3GPP TS 25.433 specification.
• In these embodiments, the UMTS protocol can be specified such that the target BS, orBS604, will not send the RadioLinkSetupResponse message. The UMTS specification for BSs can be modified so that if theBS604 is a CSG BS (and therefore operates according to restricted association with only specified UEs) and theBS604 determines that theUE606 indicated in the RadioLinkSetupRequest message is not allowed to access theBS604, then a RadioLinkSetupResponse message is not transmitted from theBS604.
• Another modification to the UMTS protocol can include the measurements being made by theUE606 only, and theUE606 making measurements on the BSs that theUE606 is not allowed to access.
• In LTE systems, theUE606 can be connected to theBS602 and make DL measurements on theBS604. TheUE606 can report those measurements to theBS602. TheBS602 can process the report and apply a coordination information algorithm. The coordination information algorithm can trigger handover or other BS coordination signaling over the X2/S1 interface to theBS604. In embodiments wherein the coordination information algorithm triggers handover signaling, even though the handover is not allowed due to theUE606 being restricted from connecting to theBS604, the information pertaining to theUE606 is still received by theBS604. TheBS604 can utilize the information pertaining to theUE606 to avoid and/or cancel the interference from theUE606.
• Regarding the X2 interface, as detailed in 3GPP TS 36.423, the Handover Request message can be used by the source BS, orBS602, to prepare the target BS, orBS604, to accept connection withUE606. In some embodiments, this message can contain an information element called RRCContext, which can map to an RRC Handover Preparation Information message as detailed in 3GPP TS 36.331 Section 10.2.3. The Handover Preparation Information message can include an AS Configuration information element that can include all the information pertaining to theUE606 including, but not limited to, the C-RNTI, a RadioResourceConfigDedicated message, which can include slow time scale information that can be employed by the target BS, orBS604, to perform avoidance, cancellation and/or other interference mitigation of theUE606 signal. If, in response to the Handover Request message, the target BS, or theBS604, does not respond with a Handover Acknowledgement message, then the handover will not be executed. Accordingly, in these embodiments, the target BS, orBS604, can obtain all of the information typically obtained during the handover without accepting handover of theUE606. In other embodiments wherein any type of coordination signaling is exchanged betweenBS602 andBS604, the target BS, orBS604, can obtain the information typically obtained for coordination of communication with theUE606 but need not allow access to theBS604 by theUE606. The information can be utilized to avoid or cancel the interference from theUE606.
• In some embodiments, the UMTS protocol can be modified such that UEs are allowed to make and report measurements on BSs to which the UE is not allowed to connect. The source BSs can be allowed to initiate a Handover Request message or equivalent or similar message to target BSs for which the UE is restricted from communicating. The target BSs can receive the Handover Request message and determine that the indicated UE is not allowed to connect to the target BS. The target BS can nonetheless process the Handover Request message but not transmit a Handover Acknowledgment message to the source BS, which transmitted the Handover Request message. Accordingly, for UMTS, coordination information signaling on the backhaul can be used to convey information to a BS about the interfering signal of the UE. This information can be conveyed even though the target BS will not allow the UE to connect to it.
• In some embodiments, an LTE system can be specified such that the PUCCH and a PUSCH can be transmitted together, such as in a same subframe. In these embodiments, an UL assignment for the UE606 (including RBs assigned, transport format on accompanying PUSCH data, etc.) can be reflected in the UL transmission for LTE systems.
• The foregoing is a method using existing coordination information signaling to provide the slow time scale information toBS604 for managing the interference ofUE606. However, other methods employing slow time scale information can also be employed, as will be now discussed.
• is a flow chart of an example of another method employing slow time scale information for facilitating interference management in accordance with various aspects set forth herein.FIG. 6B will be described with reference toFIGS. 6A and 6B.
• At640,method630 can includeBS604 obtaining information aboutUE606. As noted above,UE606 can be served byBS602. Further,UE606 can be restricted from accessingBS602 due to restricted access rules employed byBS602.
• In some embodiments, the information obtained byBS604 is slow time scale information. The slow time scale information can be provided in coordination information signaling, which can include, but is not limited to, signaling for handover purposes and for other purposes including, but not limited to, power control.
• In some embodiments, for UMTS systems, the slow time scale information can be a scrambling code used by theUE606, UL channel configuration information for theUE606. The information can be transmitted to theUE606 from theBS602. Further, in some embodiments, the UL channel configuration information can include an UL DPCH or an E-DPCH.
• In some embodiments, for UMTS systems, the slow time scale information can include a C-RNTI associated with theUE606, persistent assignment information for theUE606, DPCH configuration information about theUE606 or a number of control channel symbols being used by the servingBS602. The persistent assignment information for theUE606 can include, but is not limited to, assigned RBs, information indicative of periodicity of a persistent assignment associated with the UE, information indicative of modulation used in a persistent assignment associated with theUE606, information indicative of a coding rate applicable to a persistent assignment associated with theUE606 and information indicative of hopping of the persistent assignment associated with theUE606. In some embodiments, the DPCH configuration information about theUE606 includes: a PUCCH, a PUSCH or an SRS.
• The slow time scale information can be obtained by theBS604 in at least two general cases. First, in response to theBS602 receiving, from theUE606, a measurement report aboutBS604. The measurement report can include at least one of: received signal strength indicator measurements, reference signal received power measurements or reference signal received quality measurements. The slow time scale information can be sent to theBS604 if the measurement report is indicative of at least one of the received signal strength indicator measurements, reference signal received power measurements or reference signal received quality measurements being greater than a threshold.
• Second, the slow time scale information can be obtained by theBS604 upon the initiation of theBS604. For example, if theUE606 attempts to connect to theBS604,BS604 can take steps to initiate acquisition of the slow time scale information.
• At650,method630 can include theBS604 determining signal information for theUE606. The signal information can be determined based, at least, in part, on the slow time scale information.
• At660,method630 can include theBS604 disallowing access to theUE606 due to restricted access rules for the non-serving BS. Nonetheless, at670,method630 can also include theBS604 performing interference management of the interference from theUE606. The interference management can be performed based, at least, in part, on the determined signal information for theUE606.
• Performing interference management can include interference avoidance, cancellation, power control, erasures of symbols deemed interfered with, and other mitigation techniques.
• For example, in some embodiments, performing interference management comprises at least one of: canceling an UL signal transmitted from theUE606, scheduling transmission of a signal on a carrier different than a carrier on which an UL signal is scheduled from theUE606 or performing power control for a UE served by BS604 (such asUE506 whenBS604 isBS502 ofFIG. 5).
• In some embodiments, performing interference management comprises: demodulating and decoding, byBS604, a DPCCH or E-DPCCH to determine a TFCI or E-TFCI of an accompanying DPDCH or E-PDCH.
• In some embodiments, performing interference management comprises: demodulating and decoding, byBS604, a DPCCH or E-DPCCH to determine a TFCI or E-TFCI of an accompanying DPDCH or E-DPDCH; demodulating the accompanying DPDCH or E-DPDCH; re-spreading demodulated soft symbols; canceling re-spread information from a chip-level input stream; and demodulating the DPDCH or E-DPDCH of a UE served byBS604 from a chip-level input stream after canceling re-spread information.
• In some embodiments, performing interference management atBS604 comprises: demodulating and decoding, byBS604, a DPCCH or E-DPCCH transmitted by the UE to the serving BS; determining TFCI or E-TFCI based on the demodulating and the decoding, wherein the TFCI or E-TFCI are of an accompanying DPDCH or E-DPDCH; re-encoding information symbols obtained based on the demodulating, the decoding and the determining; re-spreading information symbols; canceling re-spread information from a chip-level input stream; and demodulating and decoding the DPDCH or E-DPDCH of a UE served byBS604 from a chip-level input stream after cancellation of re-spread information.
• In various embodiments, fast time scale information can be utilized by theBS604 in addition to slow time scale information. Embodiments utilizing fast time scale information are discussed below.
• For UMTS systems, in some embodiments, theBS604 can determine fast time scale information including, but not limited to, the UL scrambling code, and information pertaining to data transmission, such as TFCI-E-TFCI, by decoding the control channels (DPCCH/E-DPCCH) that accompany the data transmission. The semi-static information on the number of DPDCHs (which can be conveyed by the slow time scale coordination information signaling previously discussed herein, the TFS being used and the like).
• For LTE systems, in some embodiments, theBS604 can determine semi-static fast time scale information including, but not limited to, C-RNTI, physical uplink control channel (PUCCH) resource assigned, PUCCH reporting formats, and/or the UE category. The semi-static information can be conveyed over the backhaul using the coordination information signaling methods previously discussed herein. TheBS604 can also determine dynamic fast time scale information including, but not limited to, RBs assigned, MCS, and/or hopping information.
• Unlike in UMTS, in LTE systems, in some embodiments, the dynamic information is not transmitted on the UL concurrently with the data. Accordingly, in some embodiments, the dynamic fast time scale information can be transmitted by theBS602 to theUE606 using the assignment channels (e.g., PDCCH). The cyclic redundancy check (CRC) on the assignment channel can be covered by the C-RNTI. TheBS604 can listen to the assignment channel for theBS602 transmission to theUE606 to determine whether the C-RNTI of theUE606 is part of a UL assignment.
• In various embodiments,BS604 can be configured to be able to perform network listening and/or snooping of relevant broadcast information. Relevant broadcast information from theBS602 to theUE606 can include, but is not limited to, the bandwidth used by theUE606, the number of antenna ports, PBCH information, and/or physical cell identifier (ID).
• In some embodiments, theBS604 can listen to the PDCCH and other DL channels transmitted from theBS602 using symbol gating methods for performing reliable listening. Symbol gating can be employed in situations where the carrier frequencies used byBS604 andBS602 are the same or close to one another. The gating approach can allowBS604 to perform network listening without being interfered by the signal transmitted by BS604 (i.e., self-interference). In some embodiments, even when the carrier frequencies are sufficiently far apart to avoid self-interference, or maintain self-interference at an acceptable level, a gating-based approach can be desirable as it can, in some embodiments, avoid the need for an extra receive chain inBS604.
• Approaches to gating, forBS602 andBS604 configured to operate according to normal and extended CP, and synchronization techniques for facilitating the same, will be described below.
• FIG. 7 illustrates example downlink and UL timelines for facilitating synchronization and gating in accordance with various aspects set forth herein. The timelines can be described with reference toFIGS. 6A and 7.
• FIG. 7 illustratesDL timelines710,720 forBS604 andBS602, respectively.FIG. 7 also illustratesUL timelines730,740 forBS602 andBS604, respectively.FIG. 7 can represent the case when bothBSs602,604 are using normal CP.
• Referring first to theDL timelines710,720,DL timeline710, can be associated withBS604, and can include transmission within one ormore subframes702a,702b,702c,702d,702e,702f. Eachsubframe702a,702b,702c,702d,702e,702fcan include afirst slot704a, and asecond time slot704b. TheBS604 can perform symbol gating over selected symbols transmitted on the DL. As shown inFIG. 7, the symbol gating operation can be performed over regions of time intimeline710 that correspond to the “X” indicia. For example, symbol gating can be performed duringtime period706a.
• TheBS602 can perform DL transmission ontimeline720. The transmission can be over one ormore subframes722a,722b,722c,722d,722e,722f. Eachsubframe722a,722b,722c,722d,722e,722fcan include afirst slot724a, and asecond slot724b. The symbol gating performed byBS604 can be during thetime period726aduring which selected symbols are transmitted on the DL fromBS602. For example, the symbol gating performed byBS604 can be during thetime period726aduring which PDCCH symbols are transmitted on the DL fromBS602 toUE606.
• In various embodiments, thesubframes702a,702b,702c,702d,702e,702fand/or thesubframes722a,722b,722c,722d,722e,722fcan be subframes for Femto BSs and/or macro BSs, corresponding to the type of theBS602 andBS604. In various embodiments, thesubframes702a,702b,702c,702d,702e,702fand/or thesubframes722a,722b,722c,722d,722e,722fcan include one or more data symbols, in addition to one or more control channel symbols.
• Referring now to theUL timelines730,740, overUL timeline730,BS602 can receive information from theUE606 over the UL. OverUL timeline740,BS604 can listen to the UL transmission transmitted from theUE606 to theBS604.
• By way of example, but not limitation,subframes722a,722b,722c,722d,722e,722fcan be considered subframes n, n+1, n+2, n+3, n+4, n+5, respectively. Also, by way of example, but not limitation,subframes702a,702b,702c,702dcan be considered subframes k, k+1, k+2, k+3, respectively.Subframes742a,742b,742ccan correspond to subframes k+4, k+5, k+7, respectively. Subframe k+5 can see interference from the UL n+4 and n+5 (722e,722f) transmission time periods.
• During subframes n and n+1, theBS604 can transmit UL assignment information to theUE606. The UL assignment information can be for subframes n+4 and n+5, respectively, which can be transmitted attime periods722eand722f, respectively.
• In general, theBS604 can align symbols transmitted onDL timeline710 from theBS604 with symbols transmittedDL timeline720 from theBS602 such that the PDCCH symbols from theBS602 do not overlap with the symbols containing the RS for theBS604. In particular, theBS604 can align symbols in transmitted from theBS604 duringtime period706ain thesecond slot704bwith PDCCH symbols transmitted fromBS602 during thefirst slot724aof subframe722a, intime period726a. In one embodiment, symbols two, three or four in thesecond slot704bcan be aligned with the first two or the first three symbols in thefirst slot724a. In some embodiments, theBS604 and/or theBS602 can be a macro BS.
• Accordingly, the three symbols attime period706atransmitted from theBS604 are gated off. TheBS604 can lower the DL transmit power during the symbols attime period706a. In some embodiments, theBS604 turns off transmission during the symbols attime period706a. TheBS604 then receives the information transmitted from theBS602 to theUE606 and performs interference management.
• Methods employing the timelines described above are as follows.FIG. 8A is a flow chart of another example method for facilitating for interference management in accordance with various aspects set forth herein. Themethod800 can be employed in UMTS.
• At810,method800 can include determining, by a non-serving BS, information about a UE. At820,method800 can include employing, by the non-serving BS, determined information about the UE to receive an UL data channel from the UE and perform interference management.
• In some embodiments, for example, in UMTS, the information can include a first portion and a second portion. The first portion can be determined based, at least, in part, on coordination information signaling received from the serving BS. The second portion can be determined by decoding control channel information transmitted by the UE. In some embodiments, the first portion includes semi-static information. The semi-static information can include: at least an uplink scrambling code for use by the UE and one of a number of uplink slot configurations being used by the UE. The control channel information transmitted by the UE can include DPCCH information or E-DPCCH information. In some embodiments, the second portion can include an UL TFCI or E-TFCI. The UL TFCI or E-TFCI can be transmitted from the UE on an UL concurrently with data.
• In some embodiments, for example, in LTE, a first portion of the information can be semi-static information. The semi-static information can be determined based, at least, in part, on coordination information signaling received from the serving BS. The semi-static information can include a cell radio network temporary identifier for the UE, a PUCCH resource assigned to the UE, a category of the UE and/or a PUCCH format. In some embodiments, a second portion of the information can be dynamic information. In some embodiments, the dynamic information can include one or more resource blocks assigned to the UE, hopping information for the UE and/or modulation and coding scheme information. In some embodiments, the dynamic information can include one or more RBs assigned to the UE, hopping information for the UE and/or MCS information can be transmitted on the PUCCH accompanying the PUSCH.
• In these embodiments, decoding the PDCCH can be performed after synchronizing aBS604 downlink subframe with aBS602 downlink subframe. In some embodiments, synchronizing, and subsequent gating, is performed based, at least, on: an interference level determined, whether the downlink transmission from the non-serving BS is a first transmission or a re-transmission and/or an extent of additional reliability to be conveyed during a downlink re-transmission by the non-serving BS.
• In some embodiments, synchronizing includes staggering theBS604 downlink subframe with theBS604 downlink subframe. The staggering can be such that a plurality of data symbols in theBS604 downlink subframe is aligned with a plurality of control channel symbols in theBS602 downlink subframe.
• The non-serving BS can then reduce or turn off the power of its transmitter and listen to the downlink from the serving BS to determine UL assignment information for the UE served by the serving BS. For example, the non-serving BS can determine: whether the UE is scheduled for UL transmission, and whether the cell radio network temporary identifier is included in an UL grant transmitted on the physical downlink control channel to the UE to determine whether the UE is scheduled to transmit on an uplink, wherein the determining is based, at least, in part, on decoding a decoded physical downlink control channel.
• In some embodiments, one or more of symbols in the subframe includes data symbols. In some embodiments, gating is performed during transmission of the PDCCH fromBS602. TheBS604 can receive the PDCCH transmission being transmitted by theBS602 to theUE606. In various embodiments, theBS604 can receive the PDCCH transmission upon decoding the DL transmission from theBS602 to theUE606.
• TheBS604 can search for the C-RNTI for theUE606 to which the PDCCH transmission was being transmitted by theBS602. TheBS604 can employ the decoded PDCCH in order to search for the C-RNTI.
• TheBS604 can decode pertinent information about a UL assignment for theUE606 based on the detected UL assignment. In some embodiments, theBS604 can detect the UL assignment for theUE606 when theBS604 listens for, and decodes, the PDCCH transmission.
• As shown inUL timelines730,740, theBS604 can listen to the UL transmission from theUE606 to theBS602. In some embodiments, listening can be performed through snooping the UL assignment information. Snooping a transmission to a UE can include trying to decode the assignments corresponding to the C-RNTI of the UE.
• TheBS604 can use the information detected from the UL assignment for interference management. Interference management can include, but is not limited to, interference avoidance, interference cancellation or other reception techniques. The interference management can be performed by theBS604 on interference resultant from theUE606 served by theBS602.
• When UL assignment information is received, the fast timescale information module618 ofBS604 can evaluate the information to determine additional parameters related to communication between theUE606 andBS602. For example, the fast timescale information module618 can determine RBs assigned, modulation and coding scheme (MCS), hopping information, and/or the like based on information determined over the PDCCH. In UMTS systems, for example, the fast timescale information module618 can synchronize with theUE606 to determine DPCCH information as an alternative/additional way to receive parameters. In this example, the fast timescale information module618 can demodulate and decode the information (e.g., to determine a transport format combination indicator (TFCI)), demodulate data symbols on DPDCH (e.g., using TFCI), and cancel interference based on the DPDCH information. In yet another example, for LTE systems, fast timescale information module618 can synchronize with theUE606 to determine DL control channel information as an alternative/additional way to receive parameters. In this example, the fast timescale information module618 can demodulate and decode the DL control channel information, demodulate data symbols transmitted on the UL (by using the demodulated and decoded control channel information), and cancel interference based on the information obtained by demodulating the data symbols transmitted on the UL.
• In some system embodiments, the fast time scale information can be dynamic information that can be exchanged betweenBSs602,604 over the backhaul of the system. For example, the fast time scale information can be exchanged over an optical fiber backhaul or a local area network with multiple BSs in an office. Further, in some embodiments, a method for determining fast time scale information autonomously at theBS604 can be employed in lieu of the fast time scale information being exchanged over the backhaul. TheBS604 can then have information for canceling and/or avoiding interference from theUE606.
• FIG. 8B is another method for facilitating interference management in a wireless communication system. At850, method840 can include synchronizing the non-serving BS to the UE using information indicative of the uplink scrambling code for use by the UE and information indicative of uplink slot configurations being used by the UE.
• The synchronizing can include: processing one or more pilot symbols of the dedicated physical control channel information or enhanced dedicated physical control channel information, and performing channel estimation.
• At860, method840 can include determining information about a UE, wherein the UE is served by a serving BS.
• In some embodiments, the information comprises a first portion and a second portion, wherein the first portion is determined based, at least, in part, on coordination information signaling obtained from the serving BS, and wherein the second portion is determined by decoding control channel information transmitted by the UE.
• The first portion can include semi-static information including at least an uplink scrambling code for use by the UE and one of a number of uplink slot configurations being used by the UE, and wherein the control channel information transmitted by the UE comprises a dedicated physical control channel information or enhanced dedicated physical control channel information.
• In some embodiments, the information comprises a first portion and a second portion, wherein the first portion is determined based, at least, in part, on coordination information signaling obtained from the serving BS, and wherein the second portion is determined by decoding control channel information transmitted by the UE.
• In some embodiments, the second portion comprises a transport format combination indicator or enhanced transport format combination indicator, wherein the transport format combination indicator or enhanced transport format combination indicator is transmitted concurrently with data on an uplink from the UE.
• At870, method840 can include employing determined information about the UE to perform interference management at a non-serving BS.
• In some embodiments, performing interference management at the non-serving BS comprises at least one of: employing uplink assignment information to cancel an uplink signal transmitted from the UE or scheduling transmission of a signal on a carrier different than a carrier on which an uplink signal from the UE is scheduled for transmission.
• In some embodiments, performing interference management at the non-serving BS comprises: demodulating and decoding, by the non-serving BS, the dedicated physical control channel information or enhanced dedicated physical control channel information to determine at least one of: the transport format combination indicator or enhanced transport format combination indicator of an accompanying dedicated physical data channel or accompanying enhanced dedicated physical data channel.
• In some embodiments, performing interference management at the non-serving BS comprises: demodulating and decoding, by the non-serving BS, the dedicated physical control channel information or enhanced dedicated physical control channel information transmitted by the UE, wherein the demodulating and decoding is performed to determine the transport format combination indicator or enhanced transport format combination indicator of an accompanying dedicated physical data channel or enhanced dedicated physical data channel; demodulating the accompanying dedicated physical data channel or enhanced dedicated physical data channel; re-spreading demodulated soft symbols; canceling re-spread information from a chip-level input stream; and demodulating a dedicated physical data channel or enhanced dedicated physical data channel of a UE served by the non-serving BS after the canceling re-spread information from a chip-level input stream. In some embodiments, performing interference management at the non-serving BS further comprises quantizing demodulated data symbols on the dedicated physical data channel or enhanced dedicated physical data channel prior to re-spreading and canceling.
• In some embodiments, performing interference management at the non-serving BS comprises: demodulating and decoding, by the non-serving BS, the dedicated physical control channel information or enhanced dedicated physical control channel information transmitted by the UE to the serving BS; determining the transport format combination indicator or enhanced transport format combination indicator based on the demodulating and decoding, wherein the transport format combination indicator or enhanced transport format combination indicator is an indicator of an accompanying dedicated physical data channel or enhanced dedicated physical data channel of the UE; demodulating and decoding the accompanying dedicated physical data channel or enhanced dedicated physical data channel of the UE; re-encoding information symbols obtained based on the demodulating and decoding and based on the determining; re-spreading information symbols; canceling re-spread information from a chip-level input stream; and demodulating and decoding the dedicated physical data channel or enhanced dedicated physical data channel of a UE served by the non-serving BS after the canceling re-spread information from a chip-level input stream.
• Numerous approaches to gating can be taken based on the type of cyclic prefix for which theBS602 andBS604 are configured.FIG. 9 is a block diagram of example subframe structures for normal and extended CP for facilitating interference management in accordance with various aspects set forth herein.FIG. 9 illustrates an embodiment utilizing the 2-transmit antenna case for theBS604, so only the resource elements (REs) labels R0 or R1 are valid. The REs R0 and R1 can be indicated by the blocks in which the “X” indicator is provided inFIG. 9. As shown inFIG. 9, for normal CP,OFDM symbols0,1,2,3,4,5, and6 are provided in single slot, while for extended CP,OFDM symbols0,1,2,3,4 and5 are provided in a single slot.
• Detailed features of an exemplary method including synchronization, staggering of subframes and gating are as follows.FIG. 10 will be described with reference toFIG. 7. At1010, method1000 can includeBS604 synchronizing a downlink subframe fromBS604 to a downlink subframe fromBS602.
• At1020, method1000 can also include staggering the downlink subframe with the downlink subframe such that at least one of the one or more symbols of theBS602 downlink subframe is aligned with at least one of the one or more symbols of the downlink subframe.
• At1030, method1000 can include gating one or more symbols of the downlink subframe. In some embodiments, gating one or more symbols comprises reducing or ceasing a power associated with transmitting the symbols of theBS604 downlink subframe.
• In various embodiments, gating can be performed according to the type of the cyclic prefix forBS604 andBS602. In some embodiments,BS604 andBS602 are configured for normal cyclic prefix operation. In some of these embodiments, the one or more symbols of the downlink subframe comprises three PDCCH symbols, and the one or more symbols of the downlink subframe comprises symbols two, three and/or four of a second slot of the downlink subframe.
• In some embodiments, theBS604 and theBS602 are configured for normal cyclic prefix operation. In some of these embodiments, the one or more symbols of the downlink subframe comprises three PDCCH symbols, and the one or more symbols of the downlink subframe comprises symbols two, three and/or four of a second slot of theBS604 downlink subframe. In some of these embodiments, the method1090 can also include searching, during the symbols two, three and/or four of a second slot of the downlink subframe, for the C-RNTI for theUE606, and determining UL assignment information for the UE served by the serving BS.
• In some of these embodiments for normal cyclic prefix operation, specific interference management can be performed. The interference management can include at least one of: selecting a transport format or one or more RBs to assign on an UL toUE606 served by the servingBS602 or selecting an UL power control command for theUE606 served by the servingBS602.
• In some embodiments, theBS604 and the serving BS are configured for extended cyclic prefix operation. In some of these embodiments, the one or more symbols of the downlink subframe comprises three PDCCH, and the one or more symbols of the downlink subframe comprises symbols two, three and/or four of a second slot of the downlink subframe. In these embodiments, the method can also include power boosting a first symbol containing a cell-specific reference signal in the one or more symbols of the downlink subframe and not transmitting or transmitting at low power (e.g, gating) data in the one or more symbols of the downlink subframe.
• In some embodiments, theBS604 andBS602 are configured for extended cyclic prefix operation. In some of these embodiments, the one or more symbols of the downlink subframe comprises a first one or the first two PDCCH, and wherein the one or more symbols of the downlink subframe comprises symbol two or symbols two and three of a second slot of the downlink subframe. In some of these embodiments, the method can also include decoding the first two PDCCH symbols, wherein decoding comprises using control channel elements (CCEs) decoded by theBS604 during the symbols two and three of a second slot of the downlink subframe.
• In some embodiments, theBS604 andBS602 are configured for extended cyclic prefix operation. In some of these embodiments, the one or more symbols of the downlink subframe comprises a first two PDCCH, and the one or more symbols of the downlink subframe comprises symbols two, three and/or four of a second slot of the downlink subframe, wherein symbol four of the second slot includes a common reference signal and not data.
• In some embodiments, theBS604 and theBS602 are configured for extended cyclic prefix operation. In some of these embodiments, the one or more symbols of the downlink subframe comprises a first two PDCCH symbols, and the one or more symbols of the downlink subframe comprises symbols two, three and/or four of a second slot of the downlink subframe, wherein symbol four of the second slot includes a common reference signal and not data, and wherein the second slot also includes common reference signals transmitted within data RBs from theBS604.
• In some embodiments, theBS604 is configured for normal cyclic prefix operation and theBS602 is configured for extended cyclic prefix operation. In some of these embodiments, the one or more symbols of the downlink subframe comprises three PDCCH symbols, and the one or more symbols of the downlink subframe comprises three symbols, wherein a second symbol of the three symbols is synchronized to align with a first symbol of the three PDCCH.
• In some embodiments, wherein theBS602 is configured for normal cyclic prefix operation and theBS604 is configured for extended cyclic prefix operation, and wherein the one or more symbols of the downlink subframe comprises PDCCH symbols, and wherein the one or more symbols of the downlink subframe are aligned such that a second symbol of a second slot of the downlink subframe is synchronized to align with a first one of the physical downlink control channel symbols.
• Referring back toFIG. 10, at1040, method1000 can include decoding one or more symbols of the downlink subframe.
• In some embodiments, the one or more symbols of the downlink subframe are one or more PDCCH symbols. Additionally, at least a first portion of the information is semi-static information and wherein a second portion of the information is dynamic information. In some embodiments, the semi-static information is included in a coordinating message and comprises a C-RNTI for the UE, a PUCCH resource assigned to the UE, a category of the UE or a PUCCH format. In some embodiments, the dynamic information comprises a set of resource blocks assigned to the UE, hopping information for the UE or MCS information.
• At1050, method1000 can include determining information for performing interference management associated with theUE606. In some embodiments, the information can be determined based, at least, in part, on decoding one or more symbols of the downlink subframe.
• At1060, method1000 can also include performing interference management at theBS604. In some of these embodiments, performing interference management comprises: demodulating and decoding, by theBS604, PDCCH symbols of the downlink subframe; demodulating and decoding, by theBS604, data associated with theUE606 based, at least, on demodulating and decoding the PDCCH symbols of the downlink subframe; re-spreading demodulated soft symbols; canceling re-spread information from a chip-level input stream; and demodulating data associated with a UE served by theBS604 after the canceling re-spread information from a chip-level input stream. In some embodiments, performing interference management can also include quantizing demodulated soft symbols to a nearest constellation prior to re-spreading and canceling.
• FIG. 11 is a flow chart of another example method for facilitating interference management in accordance with various aspects set forth herein.
• At1110,method1100 can include determining, by a non-serving BS, information about a UE served by the serving BS, wherein the determining is performed by decoding PDCCH information transmitted from the serving BS to the UE on a downlink. At1120,method1100 can include adapting, by the non-serving BS, an UL assignment for a selected subframe of theBS604 downlink subframe based, at least, in part, on decoding the PDCCH from the serving BS during a selected subframe of theBS602 downlink subframe. At1130,method1100 can include determining UL transmission attributes for the UE served by the serving BS, wherein the determining UL transmission attributes is performed after the determining whether the UE is scheduled on the UL based on the UL assignment.
• At1140,method1100 can include employing, by the non-serving BS, determined information about the UE to perform at least one of interference management of the UE served by the serving BS or power control based, at least, in part, on interference from the UE served by the serving BS. Performing interference management can be based, at least, in part, on the determined UL transmission attributes in response to determining that the UE served by the serving BS is scheduled on the UL. Interference management can include the interference cancellation, avoidance and other reception techniques described herein.
• FIG. 12 is a flow chart of an example method for facilitating interference management in accordance with various aspects set forth herein.
• At1210,method1200 can include aBS602 receiving UL information indicative of transmissions byUE606. At1220,method1200 can include theBS604 determining, for theUE606, a first carrier on which theUE606 is transmitting, wherein the determining is based, at least, in part, on the UL information. At1230,method1200 can include transmitting signals on a second carrier in response to determining that an unacceptable level of interference is present on the first carrier, wherein the second carrier is different than the first carrier.
• In addition to, or in lieu of, the methods for interference management described above, in some embodiments, in LTE systems, performing interference management comprises performing cancellation of the PUCCH and/or SRS.
• Further, in some embodiments, in LTE systems, a method (not shown) for adapting the UL assignment to a UE served by a serving BS can be employed. The method can be based on a determination of whether the UE is scheduled on the UL. The determination can be made based on decoding the PDCCH transmitted from the serving BS to the UE during the periods for which non-serving BS symbols are gated off. By way of example, but not limitation, with reference toFIG. 7, the UL assignment can be made in subframe k+2 based on hearing the content of the n+1 subframe.
• Additionally, in some embodiments, in LTE systems, a method (not shown) for adapting the DL transmission to a UE served by a serving BS can be employed. In some embodiments, power associated with the DL transmission can be adapted. The power can be adapted based, at least, on a determination of the DL assignment to the UE. By way of example, but not limitation, with reference toFIG. 7, the UL assignment made in subframe k+2 can be adapted based on hearing the content at the n+1 subframe.
• Variously, in UMTS and/or LTS embodiments, performing interference management at the non-serving BS can include at least one of: employing the UL assignment information to cancel an UL signal transmitted from the UE, scheduling transmission of a signal on a carrier different than a carrier on which an uplink signal from the UE is scheduled for transmission. In various embodiments, interference management can include, but is not limited to, interference cancellation, interference avoidance or other reception techniques.
• In other embodiments of methods for facilitating interference management, the bandwidth and/or transport format at which a UE served by theBS604 is scheduled, can be adjusted to facilitate the gating off operation.
• In one embodiment, performing interference management of the UE comprises: canceling, by the non-serving BS, a signal transmitted from the UE, wherein the canceling is performed upon employing the UL assignment information decoded by the non-serving BS.
• In another embodiment, performing interference management of the UE comprises: demodulating and decoding, by the non-serving BS, the dedicated physical control channel information or the enhanced dedicated physical control channel information to determine a transport format combination indicator or an enhanced transport format combination indicator of an accompanying dedicated physical data channel or enhanced dedicated physical data channel.
• In another embodiment, performing interference management of the UE served by the serving BS comprises: demodulating and decoding, by the non-serving BS, the dedicated physical control channel information or the enhanced dedicated physical control channel information transmitted by the UE to the serving BS to determine a transport format combination indicator or an enhanced transport format combination indicator of an accompanying dedicated physical data channel or enhanced dedicated physical data channel, demodulating the accompanying dedicated physical data channel or enhanced dedicated physical data channel, re-spreading demodulated soft symbols, and canceling re-spread information from a chip-level input stream, demodulating the dedicated physical data channel or enhanced dedicated physical data channel of a UE served by the non-serving BS from the chip-level input stream after cancellation of the re-spread information.
• In another embodiment, performing interference management of the UE served by the serving BS comprises: demodulating, by the non-serving BS, one or more UE data symbols within the dedicated physical control channel information or the enhanced dedicated physical control channel information, wherein demodulating is based, at least, in part, on performing synchronization using one or more pilot symbols in the dedicated physical control channel information or the enhanced dedicated physical control channel information, and performing channel estimation.
• In another embodiment, performing interference management of the UE served by the serving BS comprises: demodulating, by the non-serving BS, one or more UE data symbols within the dedicated physical control channel information or the enhanced dedicated physical control channel information, wherein demodulating is based, at least, in part, on performing synchronization using one or more pilot symbols in the dedicated physical control channel information or the enhanced dedicated physical control channel information, and performing channel estimation, quantizing a demodulated one or more UE data symbols to a nearest constellation point, re-spreading a quantized demodulated one or more UE data symbols, and canceling re-spread information from a chip-level input stream.
• In another embodiment, performing interference management of the UE served by the serving BS comprises: demodulating and decoding, by the non-serving BS, the dedicated physical control channel information or enhanced dedicated physical control channel information transmitted by the UE to the serving BS; determining the transport format combination indicator or the enhanced transport format combination indicator based on the demodulating and the decoding, wherein the transport format combination indicator or the enhanced transport format combination indicator are of the accompanying dedicated physical data channel or enhanced dedicated physical data channel; demodulating and decoding the accompanying dedicated physical data channel or enhanced dedicated physical data channel of the UE served by the non-serving BS; re-encoding information symbols obtained based on the demodulating, the decoding and the determining; re-spreading information symbols; canceling re-spread information from a chip-level input stream; demodulating and decoding the dedicated physical data channel or enhanced dedicated physical data channel of a UE served by the non-serving BS from the chip-level input stream after cancellation of re-spread information.
• FIGS. 13-18 are illustrations of block diagrams of example systems employing network listening and/or interference management in accordance with various aspects set forth herein.
• Turning toFIG. 13, illustrated is a system for facilitating interference management. It is to be appreciated thatsystem1300 is represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor, hardware, software, firmware, or combination thereof.System1300 can include alogical grouping1302 of electrical components that can act in conjunction.
• For instance,logical grouping1302 can include anelectrical component1304 for obtaining information about a UE served by a serving BS. Thelogical grouping1302 can include anelectrical component1306 for determining signal information based, at least, in part, on the information.
• Thelogical grouping1302 can also include anelectrical component1308 for disallowing access to the UE served by the serving BS due to restricted access rules for the apparatus.
• Thelogical grouping1302 can also include anelectrical component1310 for performing interference management of the UE served by the serving BS
• In some embodiments, the information is slow time scale information.Logical grouping1302 can also include amemory1312 for storing information.
• Turning toFIG. 14, illustrated is a system for facilitating interference management. It is to be appreciated thatsystem1400 is represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor, hardware, software, firmware, or combination thereof.System1400 can include alogical grouping1402 of electrical components that can act in conjunction.
• For instance,logical grouping1402 can include anelectrical component1404 for determining, by a non-serving BS, information about a UE served by the serving BS.
• Logical grouping1402 can also include anelectrical component1406 for employing, by the non-serving BS, determined information about the UE to receive the UL data channel from the UE to perform interference management or power control.
• Logical grouping1404 can also include anelectrical component1408 for performing interference management on a signal transmitted by the UE served by the serving BS.
• Logical grouping1404 can also include amemory1410 for storing information about the UE.
• Turning now toFIG. 15, illustrated is a system for facilitating interference management. It is to be appreciated thatsystem1500 is represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor, hardware, software, firmware, or combination thereof.System1500 can include alogical grouping1502 of electrical components that can act in conjunction.
• For instance,logical grouping1502 can include anelectrical component1504 for determining information about a UE, wherein the UE is served by a serving BS.
• Logical grouping1502 can also include anelectrical component1506 for synchronizing the non-serving BS to the UE using information indicative of the uplink scrambling code for use by the UE and information indicative of uplink slot configurations being used by the UE.
• Logical grouping1502 can also include anelectrical component1508 for employing determined information about the UE to perform interference management at the apparatus.Logical grouping1504 can also include amemory1510 for storing information about the UE.
• Turning now toFIG. 16, illustrated is a system for facilitating interference management. It is to be appreciated thatsystem1600 is represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor, hardware, software, firmware, or combination thereof.System1700 can include alogical grouping1602 of electrical components that can act in conjunction.
• For instance,logical grouping1602 can include anelectrical component1604 for synchronizing aBS604 downlink subframe to aBS602 downlink subframe.Logical grouping1602 can also include anelectrical component1606 for staggering downlink subframe for the non-serving BS such that at least one symbol overlaps with a symbol of theBS602 downlink subframe.
• Logical grouping1602 can also include anelectrical component1608 for gating one or more symbols.Logical grouping1602 can also include anelectrical component1610 for decoding one or more symbols.
• Logical grouping1602 can also include anelectrical component1612 for determining information for performing interference management.Logical grouping1602 can also include anelectrical component1614 for performing interference management.Logical grouping1602 can also include amemory1616 for storing information.
• Turning now toFIG. 17, illustrated is a system for facilitating interference management. It is to be appreciated thatsystem1700 is represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor, hardware, software, firmware, or combination thereof.System1700 can include alogical grouping1702 of electrical components that can act in conjunction.
• For instance,logical grouping1702 can include anelectrical component1704 for determining, by a non-serving BS, information about a UE served by the serving BS, wherein the determining is performed by decoding PDCCH information transmitted from the serving BS to the UE on a downlink.
• Logical grouping1702 can include anelectrical component1706 for adapting, by the non-serving BS, an UL assignment for a selected subframe of theBS604 downlink subframe based, at least, in part, on decoding the PDCCH from the serving BS during a selected subframe of theBS602 downlink subframe.
• Logical grouping1702 can include anelectrical component1708 for determining UL transmission attributes for the UE served by the serving BS, wherein the determining UL transmission attributes is performed after the determining whether the UE is scheduled on the UL based on the UL assignment.
• Logical grouping1702 can include anelectrical component1710 for employing, by the non-serving BS, determined information about the UE to perform at least one of interference management of the UE served by the serving BS or power control based, at least, in part, on interference from the UE served by the serving BS. In various embodiments, interference management can include, but is not limited to, interference cancellation, interference avoidance or other reception techniques.
• Logical grouping1702 can include amemory1712 for storing information about the UE, UL transmission attributes and UL assignment information.
• Turning now toFIG. 18, illustrated is a system for facilitating interference management. It is to be appreciated thatsystem1800 is represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor, hardware, software, firmware, or combination thereof.System1800 can include alogical grouping1802 of electrical components that can act in conjunction.
• For instance,logical grouping1802 can include anelectrical component1804 for receiving UL information indicative of transmissions by a UE not served by the non-serving BS.
• Logical grouping1802 can include anelectrical component1806 for determining, for the UE not served by the non-serving BS, a first carrier on which the UE not served by the non-serving BS is transmitting, wherein the determining is based, at least, in part, on the UL information.
• Logical grouping1802 can include anelectrical component1808 for transmitting signals on a second carrier in response to determining that an unacceptable level of interference is present on the first carrier, wherein the second carrier is different than the first carrier.
• Logical grouping1802 can include amemory1810 for storing slow time scale and/or fast time scale information, UL information about the UE.
• A wireless multiple-access communication system can simultaneously support communication for multiple wireless access terminals. As mentioned above, each terminal can communicate with one or more BSs via transmissions on the forward and reverse links. The forward link (or DL) refers to the communication link from the BSs to the terminals, and the reverse link (or UL) refers to the communication link from the terminals to the BSs. This communication link can be established via a single-in-single-out system, a multiple-in-multiple-out (MIMO) system, or some other type of system.
• A MIMO system employs multiple (N_T) transmit antennas and multiple (N_R) receive antennas for data transmission. A MIMO channel formed by the N_Ttransmit and N_Rreceive antennas can be decomposed into N_sindependent channels, which are also referred to as spatial channels, where N_s≦min{N_T, N_R}. Each of the N_sindependent channels corresponds to a dimension. The MIMO system can provide improved performance (e.g., higher throughput and/or greater reliability) if the additional dimensionalities created by the multiple transmit and receive antennas are utilized.
• A MIMO system can support time division duplex (TDD) and frequency division duplex (FDD). In a TDD system, the forward and reverse link transmissions are on the same frequency region so that the reciprocity principle allows the estimation of the forward link channel from the reverse link channel. This enables the BS to extract transmit beam-forming gain on the forward link when multiple antennas are available at the BS.
• FIG. 19 shows an example wireless communication system in which the embodiments described herein can be employed in accordance with various aspects set forth herein. The teachings herein may be incorporated into a node (e.g., a device) employing various components for communicating with at least one other node in thewireless communication system1900.FIG. 19 depicts several sample components that may be employed to facilitate communication between nodes. Specifically,FIG. 19 illustrates a BS1910 (e.g., an access point) and a wireless device1950 (e.g., an access terminal) of a wireless communication system1900 (e.g., multiple input multiple output (MIMO) system). AtBS1910, traffic data for a number of data streams is provided from adata source1912 to a transmit (TX)data processor1914.
• In some aspects, each data stream is transmitted over a respective transmit antenna. TheTX data processor1914 formats, codes, and interleaves the traffic data for each data stream based on a particular coding scheme selected for that data stream to provide coded data.
• The coded data for each data stream may be multiplexed with pilot data using OFDM techniques. The pilot data is typically a known data pattern that is processed in a known manner and may be used at the receiver system to estimate the channel response. The multiplexed pilot and coded data for each data stream is then modulated (i.e., symbol mapped) based on a particular modulation scheme (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QSPK), m-ary phase-shift keying (M-PSK), or multi-level quadrature amplitude modulation (M-QAM)) selected for that data stream to provide modulation symbols. The data rate, coding, and modulation for each data stream may be determined by instructions performed by aprocessor1930. Adata memory1932 may store program code, data, and other information used by theprocessor1930 or other components of theBS1910.
• The modulation symbols for all data streams are then provided to aTX MIMO processor1920, which may further process the modulation symbols (e.g., for OFDM). TheTX MIMO processor1920 then provides N_Tmodulation symbol streams to N_Ttransceivers (XCVR)1922A through1922T. In some aspects, theTX MIMO processor1920 applies beam-forming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.
• Each transceiver1922 receives and processes a respective symbol stream to provide one or more analog signals, and further conditions (e.g., amplifies, filters, and upconverts) the analog signals to provide a modulated signal suitable for transmission over the MIMO channel. N_Tmodulated signals fromtransceivers1922A through1922T are then transmitted from N_Tantennas1924A through1924T, respectively.
• At thewireless device1950, the transmitted modulated signals are received by N_Rantennas1952A through1952R and the received signal from each antenna1952 is provided to a respective transceiver (XCVR)1954A through1954R. Each transceiver1954 conditions (e.g., filters, amplifies, and downconverts) a respective received signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding “received” symbol stream.
• A receive (RX)data processor1960 then receives and processes the N_Rreceived symbol streams from N_Rtransceivers1954 based on a particular receiver processing technique to provide N_T“detected” symbol streams. TheRX data processor1960 then demodulates, deinterleaves, and decodes each detected symbol stream to recover the traffic data for the data stream. The processing by theRX data processor1960 is complementary to that performed by theTX MIMO processor1920 and theTX data processor1914 at theBS1910.
• Aprocessor1970 periodically determines which pre-coding matrix to use (discussed below). Theprocessor1970 formulates a reverse link message comprising a matrix index portion and a rank value portion. Adata memory1972 may store program code, data, and other information used by theprocessor1970 or other components of thewireless device1950.
• The reverse link message may comprise various types of information regarding the communication link and/or the received data stream. The reverse link message is then processed by aTX data processor1938, which also receives traffic data for a number of data streams from a data source1936, modulated by amodulator1980, conditioned by thetransceivers1954A through1954R, and transmitted back to theBS1910.
• At theBS1910, the modulated signals from thewireless device1950 are received by the antennas1924, conditioned by the transceivers1922, demodulated by a demodulator (DEMOD)1940, and processed by aRX data processor1942 to extract the reverse link message transmitted by thewireless device1950. Theprocessor1930 then determines which pre-coding matrix to use for determining the beam-forming weights then processes the extracted message.
• FIG. 19 also illustrates that the communication components may include one or more components that perform interference control operations as taught herein. For example, an interference (INTER.)control component1990 may cooperate with theprocessor1930 and/or other components of theBS1910 to send/receive signals to/from another device (e.g., wireless device1950) as taught herein. Similarly, aninterference control component1992 may cooperate with theprocessor1970 and/or other components of thewireless device1950 to send/receive signals to/from another device (e.g., BS1910). It should be appreciated that for eachBS1910 andwireless device1950, the functionality of one or more of the described components may be provided by a single component. For example, a single processing component may provide the functionality of theinterference control component1990 and theprocessor1930 and a single processing component may provide the functionality of theinterference control component1992 and theprocessor1970.
• In an aspect, logical channels can be classified into Control Channels and Traffic Channels. Logical Control Channels can include a Broadcast Control Channel (BCCH), which is a DL channel for broadcasting system control information. Further, Logical Control Channels can include a Paging Control Channel (PCCH), which is a DL channel that transfers paging information. Moreover, the Logical Control Channels can include a Multicast Control Channel (MCCH), which is a Point-to-multipoint DL channel used for transmitting Multimedia Broadcast and Multicast Service (MBMS) scheduling and control information for one or several Multicast Traffic Channels (MTCHs). Generally, after establishing a Radio Resource Control (RRC) connection, this channel is only used by UEs that receive multimedia broadcast multicast service (MBMS) (e.g., old MCCH+MSCH). Additionally, the Logical Control Channels can include a Dedicated Control Channel (DCCH), which is a Point-to-point bi-directional channel that transmits dedicated control information and can be used by UEs having a radio resource control (RRC) connection. In an aspect, the Logical Traffic Channels can comprise a Dedicated Traffic Channel (DTCH), which is a Point-to-point bi-directional channel dedicated to one UE for the transfer of user information. Also, the Logical Traffic Channels can include an MBMS traffic channel (MTCH) for Point-to-multipoint DL channel for transmitting traffic data.
• In an aspect, Transport Channels are classified into DL and UL. DL Transport Channels can include a Broadcast Channel (BCH), a Downlink Shared Data Channel (DL-SDCH) and a Paging Channel (PCH). The PCH can support UE power saving (e.g., Discontinuous Reception (DRX) cycle can be indicated by the network to the UE) by being broadcasted over an entire cell and being mapped to Physical layer (PHY) resources that can be used for other control/traffic channels. The UL Transport Channels can comprise a Random Access Channel (RACH), a Request Channel (REQCH), an Uplink Shared Data Channel (UL-SDCH) and a plurality of PHY channels.
• The PHY channels can include a set of DL channels and UL channels. For example, the DL PHY channels can include: Common Pilot Channel (CPICH); Synchronization Channel (SCH); Common Control Channel (CCCH); Shared DL Control Channel (SDCCH); Multicast Control Channel (MCCH); Shared UL Assignment Channel (SUACH); Acknowledgement Channel (ACKCH); DL Physical Shared Data Channel (DL-PSDCH); UL Power Control Channel (UPCCH); Paging Indicator Channel (PICH); and/or Load Indicator Channel (LICH). By way of further illustration, the UL PHY Channels can include: Physical Random Access Channel (PRACH); Channel Quality Indicator Channel (CQICH); Acknowledgement Channel (ACKCH); Antenna Subset Indicator Channel (ASICH); Shared Request Channel (SREQCH); UL Physical Shared Data Channel (UL-PSDCH); and/or Broadband Pilot Channel (BPICH).
• It is to be understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For a hardware implementation, the processing units can be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors and/or other electronic units designed to perform the functions described herein, or a combination thereof.
• When the embodiments are implemented in software, firmware, middleware or microcode, program code or code segments, they can be stored in a machine-readable medium (or a computer-readable medium), such as a storage component. A code segment can represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment can be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. can be passed, forwarded, or transmitted using any suitable means including memory sharing, message passing, token passing, network transmission, etc.
• For a software implementation, the techniques described herein can be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The software codes can be stored in memory units and executed by processors. The memory unit can be implemented within the processor or external to the processor, in which case it can be communicatively coupled to the processor via various means as is known in the art.
• What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the described embodiments are intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.

Claims (44)

1. A method for facilitating interference management in a wireless communication system, the method comprising:

determining information about a user equipment, wherein the user equipment is served by a serving base station; and

employing determined information about the user equipment to perform interference management at a non-serving base station.

2. The method ofclaim 1, wherein the information comprises a first portion and a second portion, wherein the first portion is determined based, at least, in part, on coordination information signaling obtained from the serving base station, and wherein the second portion is determined by decoding control channel information transmitted by the user equipment.

3. The method ofclaim 2, wherein the first portion comprises semi-static information including at least an uplink scrambling code for use by the user equipment and one of a number of uplink slot configurations being used by the user equipment, and wherein the control channel information transmitted by the user equipment comprises a dedicated physical control channel information or enhanced dedicated physical control channel information.

4. The method ofclaim 2, wherein the second portion comprises a transport format combination indicator or enhanced transport format combination indicator, wherein the transport format combination indicator or enhanced transport format combination indicator is transmitted concurrently with data on an uplink from the user equipment.

5. The method ofclaim 4, further comprising synchronizing the non-serving base station to the user equipment using information indicative of the uplink scrambling code for use by the user equipment and information indicative of uplink slot configurations being used by the user equipment, wherein the second portion is determined after synchronizing.

6. The method ofclaim 5, wherein synchronizing comprises processing one or more pilot symbols of the dedicated physical control channel information or enhanced dedicated physical control channel information, and performing channel estimation.

7. The method ofclaim 6, wherein performing interference management at the non-serving base station comprises at least one of: employing uplink assignment information to cancel an uplink signal transmitted from the user equipment, scheduling transmission of a signal on a carrier different than a carrier on which an uplink signal from the user equipment is scheduled for transmission or adjusting power of a user equipment served by the non-serving base station.

8. The method ofclaim 6, wherein performing interference management at the non-serving base station comprises:

demodulating and decoding, by the non-serving base station, the dedicated physical control channel information or enhanced dedicated physical control channel information to determine at least one of: the transport format combination indicator or enhanced transport format combination indicator of an accompanying dedicated physical data channel or accompanying enhanced dedicated physical data channel.

9. The method ofclaim 8, wherein performing interference management at the non-serving base station further comprises:

demodulating the accompanying dedicated physical data channel or enhanced dedicated physical data channel;

re-spreading demodulated soft symbols;

canceling re-spread information from a chip-level input stream; and

demodulating a dedicated physical data channel or enhanced dedicated physical data channel of a user equipment served by the non-serving base station after the canceling re-spread information from a chip-level input stream.

10. The method ofclaim 9, wherein performing interference management at the non-serving base station further comprises quantizing demodulated data symbols on the dedicated physical data channel or enhanced dedicated physical data channel prior to re-spreading and canceling.

11. The method ofclaim 6, wherein performing interference management at the non-serving base station comprises:

demodulating and decoding, by the non-serving base station, the dedicated physical control channel information or enhanced dedicated physical control channel information transmitted by the user equipment to the serving base station;

determining the transport format combination indicator or enhanced transport format combination indicator based on the demodulating and decoding, wherein the transport format combination indicator or enhanced transport format combination indicator is an indicator of an accompanying dedicated physical data channel or enhanced dedicated physical data channel of the user equipment;

demodulating and decoding the accompanying dedicated physical data channel or enhanced dedicated physical data channel of the user equipment;

re-encoding information symbols obtained based on the demodulating and decoding and based on the determining;

re-spreading information symbols;

canceling re-spread information from a chip-level input stream; and

demodulating and decoding the dedicated physical data channel or enhanced dedicated physical data channel of a user equipment served by the non-serving base station after the canceling re-spread information from a chip-level input stream.

12. A computer program product, comprising:

a computer-readable medium, comprising:

a first set of codes for causing a computer to determine information about a user equipment, wherein the user equipment is served by a serving base station; and

a second set of codes for causing a computer to employ determined information about the user equipment to perform interference management at the computer, wherein a non-serving base station includes the computer.

13. The computer program product ofclaim 12, wherein the information comprises a first portion and a second portion, wherein the first portion is determined based, at least, in part, on coordination information signaling obtained from the serving base station, and wherein the second portion is determined by decoding control channel information transmitted by the user equipment.

14. The computer program product ofclaim 13, wherein the first portion comprises semi-static information including at least an uplink scrambling code for use by the user equipment and one of a number of uplink slot configurations being used by the user equipment, and wherein the control channel information transmitted by the user equipment comprises a dedicated physical control channel information or enhanced dedicated physical control channel information.

15. The computer program product ofclaim 13, wherein the second portion comprises a transport format combination indicator or enhanced transport format combination indicator, wherein the transport format combination indicator or enhanced transport format combination indicator is transmitted concurrently with data on an uplink from the user equipment.

16. The computer program product ofclaim 15, further comprising a third set of codes for causing the computer to synchronize the non-serving base station to the user equipment using information indicative of the uplink scrambling code for use by the user equipment and information indicative of uplink slot configurations being used by the user equipment, wherein the second portion is determined after synchronizing.

17. The computer program product ofclaim 16, wherein synchronizing comprises processing one or more pilot symbols of the dedicated physical control channel information or enhanced dedicated physical control channel information, and performing channel estimation.

18. The computer program product ofclaim 17, wherein performing interference management at the non-serving base station comprises at least one of: employing uplink assignment information to cancel an uplink signal transmitted from the user equipment, scheduling transmission of a signal on a carrier different than a carrier on which an uplink signal from the user equipment is scheduled for transmission or adjusting power of a user equipment served by the non-serving base station.

19. The computer program product ofclaim 17, wherein performing interference management at the computer comprises:

demodulating and decoding the dedicated physical control channel information or enhanced dedicated physical control channel information to determine at least one of: the transport format combination indicator or enhanced transport format combination indicator of an accompanying dedicated physical data channel or accompanying enhanced dedicated physical data channel.

20. The computer program product ofclaim 19, wherein performing interference management at the computer further comprises:

demodulating the accompanying dedicated physical data channel or enhanced dedicated physical data channel;

re-spreading demodulated soft symbols;

canceling re-spread information from a chip-level input stream; and

demodulating a dedicated physical data channel or enhanced dedicated physical data channel of a user equipment served by the computer after the canceling re-spread information from a chip-level input stream.

21. The computer program product ofclaim 20, wherein performing interference management at the non-serving base station further comprises quantizing demodulated data symbols on the dedicated physical data channel or enhanced dedicated physical data channel prior to re-spreading and canceling.

22. The computer program product ofclaim 17, wherein performing interference management at the computer comprises:

demodulating and decoding the dedicated physical control channel information or enhanced dedicated physical control channel information transmitted by the user equipment to the serving base station;

determining the transport format combination indicator or enhanced transport format combination indicator based on the demodulating and decoding, wherein the transport format combination indicator or enhanced transport format combination indicator is an indicator of an accompanying dedicated physical data channel or enhanced dedicated physical data channel of the user equipment;

demodulating and decoding the accompanying dedicated physical data channel or enhanced dedicated physical data channel of the user equipment;

re-encoding information symbols obtained based on the demodulating and decoding and based on the determining;

re-spreading information symbols;

canceling re-spread information from a chip-level input stream; and

demodulating and decoding the dedicated physical data channel or enhanced dedicated physical data channel of a user equipment served by the computer after the canceling re-spread information from a chip-level input stream.

23. An apparatus, comprising:

means for determining information about a user equipment, wherein the user equipment is served by a serving base station; and

means for employing determined information about the user equipment to perform interference management at the apparatus.

24. The apparatus ofclaim 23, wherein the information comprises a first portion and a second portion, wherein the first portion is determined based, at least, in part, on coordination information signaling obtained from the serving base station, and wherein the second portion is determined by decoding control channel information transmitted by the user equipment.

25. The apparatus ofclaim 24, wherein the first portion comprises semi-static information including at least an uplink scrambling code for use by the user equipment and one of a number of uplink slot configurations being used by the user equipment, and wherein the control channel information transmitted by the user equipment comprises a dedicated physical control channel information or enhanced dedicated physical control channel information.

26. The apparatus ofclaim 24, wherein the second portion comprises a transport format combination indicator or enhanced transport format combination indicator, wherein the transport format combination indicator or enhanced transport format combination indicator is transmitted concurrently with data on an uplink from the user equipment.

27. The apparatus ofclaim 26, further comprising means for synchronizing the non-serving base station to the user equipment using information indicative of the uplink scrambling code for use by the user equipment and information indicative of uplink slot configurations being used by the user equipment, wherein the second portion is determined after synchronizing.

28. The apparatus ofclaim 27, wherein synchronizing comprises processing one or more pilot symbols of the dedicated physical control channel information or enhanced dedicated physical control channel information, and performing channel estimation.

29. The apparatus ofclaim 28, wherein performing interference management at the non-serving base station comprises at least one of: employing uplink assignment information to cancel an uplink signal transmitted from the user equipment, scheduling transmission of a signal on a carrier different than a carrier on which an uplink signal from the user equipment is scheduled for transmission or adjusting power of a user equipment served by the non-serving base station.

30. The apparatus ofclaim 28, performing interference management at the apparatus comprises:

demodulating and decoding the dedicated physical control channel information or enhanced dedicated physical control channel information to determine at least one of: the transport format combination indicator or enhanced transport format combination indicator of an accompanying dedicated physical data channel or accompanying enhanced dedicated physical data channel.

31. The apparatus ofclaim 30, wherein performing interference management at the apparatus further comprises:

demodulating the accompanying dedicated physical data channel or enhanced dedicated physical data channel;

re-spreading demodulated soft symbols;

canceling re-spread information from a chip-level input stream; and

demodulating a dedicated physical data channel or enhanced dedicated physical data channel of a user equipment served by the apparatus after the canceling re-spread information from a chip-level input stream.

32. The apparatus ofclaim 31, wherein performing interference management at the apparatus further comprises quantizing demodulated data symbols on the dedicated physical data channel or enhanced dedicated physical data channel prior to re-spreading and canceling.

33. The apparatus ofclaim 28, wherein performing interference management at the apparatus comprises:

demodulating and decoding the dedicated physical control channel information or enhanced dedicated physical control channel information transmitted by the user equipment to the serving base station;

determining the transport format combination indicator or enhanced transport format combination indicator based on the demodulating and decoding, wherein the transport format combination indicator or enhanced transport format combination indicator is an indicator of an accompanying dedicated physical data channel or enhanced dedicated physical data channel of the user equipment;

demodulating and decoding the accompanying dedicated physical data channel or enhanced dedicated physical data channel of the user equipment;

re-encoding information symbols obtained based on the demodulating and decoding and based on the determining;

re-spreading information symbols;

canceling re-spread information from a chip-level input stream; and

demodulating and decoding the dedicated physical data channel or enhanced dedicated physical data channel of a user equipment served by the apparatus after the canceling re-spread information from a chip-level input stream.

34. An apparatus, comprising:

a non-serving base station configured to:

determine information about a user equipment, wherein the user equipment is served by a serving base station; and

employ determined information about the user equipment to perform interference management at the non-serving base station.

35. The apparatus ofclaim 34, wherein the information comprises a first portion and a second portion, wherein the first portion is determined based, at least, in part, on coordination information signaling obtained from the serving base station, and wherein the second portion is determined by decoding control channel information transmitted by the user equipment.

36. The apparatus ofclaim 35, wherein the first portion comprises semi-static information including at least an uplink scrambling code for use by the user equipment and one of a number of uplink slot configurations being used by the user equipment, and wherein the control channel information transmitted by the user equipment comprises a dedicated physical control channel information or enhanced dedicated physical control channel information.

37. The apparatus ofclaim 35, wherein the second portion comprises a transport format combination indicator or enhanced transport format combination indicator, wherein the transport format combination indicator or enhanced transport format combination indicator is transmitted concurrently with data on an uplink from the user equipment.

38. The apparatus ofclaim 37, wherein the non-serving base station is further configured to synchronize the non-serving base station to the user equipment using information indicative of the uplink scrambling code for use by the user equipment and information indicative of uplink slot configurations being used by the user equipment, wherein the second portion is determined after synchronizing.

39. The apparatus ofclaim 38, wherein synchronizing comprises processing one or more pilot symbols of the dedicated physical control channel information or enhanced dedicated physical control channel information, and performing channel estimation.

40. The apparatus ofclaim 39, wherein performing interference management at the non-serving base station comprises at least one of: employing uplink assignment information to cancel an uplink signal transmitted from the user equipment, scheduling transmission of a signal on a carrier different than a carrier on which an uplink signal from the user equipment is scheduled for transmission or adjusting power of a user equipment served by the non-serving base station.

41. The apparatus ofclaim 39, wherein performing interference management at the non-serving base station comprises:

demodulating and decoding the dedicated physical control channel information or enhanced dedicated physical control channel information to determine at least one of: the transport format combination indicator or enhanced transport format combination indicator of an accompanying dedicated physical data channel or accompanying enhanced dedicated physical data channel.

42. The apparatus ofclaim 41, wherein performing interference management at the non-serving base station further comprises:

demodulating the accompanying dedicated physical data channel or enhanced dedicated physical data channel;

re-spreading demodulated soft symbols;

canceling re-spread information from a chip-level input stream; and

demodulating a dedicated physical data channel or enhanced dedicated physical data channel of a user equipment served by the non-serving base station after the canceling re-spread information from a chip-level input stream.

43. The apparatus ofclaim 42, wherein performing interference management at the non-serving base station further comprises quantizing demodulated data symbols on the dedicated physical data channel or enhanced dedicated physical data channel prior to re-spreading and canceling.

44. The apparatus ofclaim 39, wherein performing interference management at the non-serving base station comprises:

demodulating and decoding the dedicated physical control channel information or enhanced dedicated physical control channel information transmitted by the user equipment to the serving base station;

determining the transport format combination indicator or enhanced transport format combination indicator based on the demodulating and decoding, wherein the transport format combination indicator or enhanced transport format combination indicator is an indicator of an accompanying dedicated physical data channel or enhanced dedicated physical data channel of the user equipment;

demodulating and decoding the accompanying dedicated physical data channel or enhanced dedicated physical data channel of the user equipment;

re-encoding information symbols obtained based on the demodulating and decoding and based on the determining;

re-spreading information symbols;

canceling re-spread information from a chip-level input stream; and

demodulating and decoding the dedicated physical data channel or enhanced dedicated physical data channel of a user equipment served by the non-serving base station after the canceling re-spread information from a chip-level input stream.

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