The application is a divisional application of PCT international application No. PCT/US2018/015894, international application No. 2018, 01 month and 30 days, application No. 201880006005.1 entering China national stage, and application name of 'reliable unlicensed uplink transmission in NR URLLC'.
The present application claims priority from U.S. provisional patent application Ser. No. 62/455,439, filed on 2/6 of 2017, entitled "RELIABLE UPLINK TRANSMISSION WITHOUT GRANT IN NR URLLC (reliable unlicensed uplink transmission in NR URLLC)", the entire contents of which are incorporated herein by reference.
Detailed Description
The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of others. Embodiments given in the claims include all available equivalents of those claims.
Fig. 1 illustrates an architecture of a system 100 of a network in accordance with certain embodiments. The system 100 is shown to include a User Equipment (UE) 101 and a UE 102. The UEs 101 and 102 are illustrated as smartphones (e.g., handheld touch screen mobile computing devices connectable to one or more cellular networks), but may also include any mobile or non-mobile computing device, such as a Personal Data Assistant (PDA), pager, laptop computer, desktop computer, wireless handset, or any computing device that includes a wireless communication interface.
In some embodiments, any of the UEs 101 and 102 can comprise an internet of things (IoT) UE, which can include a network access layer designed for low power IoT applications that utilize short-term UE connections. IoTUE can utilize technologies such as machine-to-machine (M2M) or Machine Type Communication (MTC) to exchange data with MTC servers or devices via Public Land Mobile Networks (PLMNs), proximity-based services (ProSe) or device-to-device (D2D) communications, sensor networks, or IoT networks. The M2M or MTC data exchange may be a machine initiated data exchange. IoT networks describe interconnected IoT UEs that may include uniquely identifiable embedded computing devices (within the internet infrastructure) with short-term connections. The IoT UE may execute a background application (e.g., keep-alive messages, status updates, etc.) to facilitate connection of the IoT network.
UEs 101 and 102 may be configured to connect (e.g., communicatively couple) with a Radio Access Network (RAN) 110—ran 110 may be, for example, an evolved Universal Mobile Telecommunications System (UMTS) terrestrial radio access network (E-UTRAN), a next generation RAN (NG RAN), or other type of RAN. The UEs 101 and 102 utilize connections 103 and 104, respectively, each of which includes a physical communication interface or layer (discussed in further detail below); in this example, connections 103 and 104 are illustrated as air interfaces to enable communicative coupling and can be consistent with cellular communication protocols, such as global system for mobile communications (GSM) protocols, code Division Multiple Access (CDMA) network protocols, push-to-talk (PTT) protocols, PTT Over Cellular (POC) protocols, universal Mobile Telecommunications System (UMTS) protocols, 3GPP Long Term Evolution (LTE) protocols, 5G/NR protocols, and so forth.
In this embodiment, the UEs 101 and 102 may further exchange communication data directly via the ProSe interface 105. Alternatively, proSe interface 105 may be referred to as a side link interface including one or more logical channels, including, but not limited to, a physical side link control channel (PSCCH), a physical side link shared channel (PSSCH), a physical side link discovery channel (PSDCH), and a physical side link broadcast channel (PSBCH).
UE 102 is shown configured to access an Access Point (AP) 106 via a connection 107. Connection 107 can comprise a local wireless connection, such as a connection consistent with any IEEE 802.11 protocol, where AP 106 would comprise a wireless fidelity (WiiFi) router. In this example, the AP 106 is shown connected to the internet and not to the core network of the wireless system (described in further detail below).
RAN 110 can include one or more access nodes that enable connections 103 and 104. These Access Nodes (ANs) can be referred to as Base Stations (BS), nodebs, evolved nodebs (enbs), next generation nodebs (gigabit nodebs-gnbs), RAN nodes, etc., and can include ground stations (e.g., ground access points) or satellite stations that provide coverage within a geographic area (e.g., cell). RAN 110 may include one or more RAN nodes (e.g., macro RAN node 111) for providing macro cells, and one or more RAN nodes (e.g., low Power (LP) RAN node 112) for providing femto cells or pico cells (e.g., cells with smaller coverage areas, smaller user capacities, or higher bandwidths than macro cells).
Either of the RAN nodes 111 and 112 can terminate the air interface protocol and can be the first point of contact for the UEs 101 and 102. In some embodiments, any of RAN nodes 111 and 112 are capable of satisfying various logical functions of RAN 110, including, but not limited to, radio Network Controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management.
According to some embodiments, UEs 101 and 102 can be configured to communicate with each other or any of RAN nodes 111 and 112 over a multicarrier communication channel using Orthogonal Frequency Division Multiplexing (OFDM) communication signals in accordance with various communication techniques such as, but not limited to, orthogonal Frequency Division Multiple Access (OFDMA) communication techniques (e.g., for downlink communications) or single carrier frequency division multiple access (SC-FDMA) communication techniques (e.g., for uplink and ProSe or side link communications), although the scope of the embodiments is not limited in this respect. The OFDM signal can include a plurality of orthogonal subcarriers.
In some embodiments, the downlink resource grid can be used for downlink transmissions from any of the RAN nodes 111 and 112 to the UEs 101 and 102, while the uplink transmissions can utilize similar techniques. The grid can be a time-frequency grid, referred to as a resource grid or time-frequency resource grid, which is a physical resource in the downlink in each time slot. This time-frequency plane representation is a common practice for OFDM systems, which makes radio resource allocation intuitive. Each column and each row of the resource grid corresponds to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in the radio frame. The smallest time-frequency unit in the resource grid is denoted as a resource element. Each resource grid includes a plurality of resource blocks that describe the mapping of certain physical channels to resource elements. Each resource block includes a set of resource elements; in the frequency domain, this may represent the minimum amount of resources that can be currently allocated. There are several different physical downlink channels transmitted using such resource blocks.
The Physical Downlink Shared Channel (PDSCH) may carry user data and higher layer signaling to UEs 101 and 102. The Physical Downlink Control Channel (PDCCH) may carry information on a transport format and resource allocation related to the PDSCH channel, etc. It may also inform UEs 101 and 102 about the transport format, resource allocation, and H-ARQ (hybrid automatic repeat request) information related to the uplink shared channel. Typically, downlink scheduling (allocation of control and shared channel resource blocks to UEs 102 within a cell) may be performed at either of the RAN nodes 111 and 112 based on channel quality information fed back from either of the UEs 101 and 102. The downlink resource allocation information may be transmitted on a PDCCH for (e.g., allocated to) each of the UEs 101 and 102.
The PDCCH may transmit control information using a Control Channel Element (CCE). The PDCCH complex-valued symbols may first be organized into quadruples before mapping to resource elements, and the quadruples may then be permuted using a sub-block interleaver for rate matching. Each PDCCH may be transmitted using one or more of these CCEs, where each CCE may correspond to nine sets of four physical resource elements known as Resource Element Groups (REGs). Four Quadrature Phase Shift Keying (QPSK) symbols may be mapped to each REG. The PDCCH can be transmitted using one or more CCEs depending on the size of Downlink Control Information (DCI) and channel conditions. There are four or more different PDCCH formats defined in LTE with different numbers of CCEs (e.g., aggregation level, l=1, 2,4, or 8).
Some embodiments may use concepts for resource allocation of control channel information, which are extensions of the concepts described above. For example, some embodiments may utilize an Enhanced Physical Downlink Control Channel (EPDCCH) that uses PDSCH resources for control information transmission. The EPDCCH may be transmitted using one or more Enhanced Control Channel Elements (ECCEs). Similar to above, each ECCE may correspond to nine sets of four physical resource elements known as Enhanced Resource Element Groups (EREGs). In some cases, ECCEs may have other amounts of EREGs.
RAN 110 is shown communicatively coupled to a Core Network (CN) 120 via an SI interface 113. In an embodiment, the CN 120 may be an Evolved Packet Core (EPC) network, a next generation packet core (NPC) network, or some other type of CN. In this embodiment, the S1 interface 113 is divided into two parts: an S1-U interface 114, which carries traffic data between RAN nodes 111 and 112 and a serving gateway (S-GW) 122, and an S1-Mobility Management Entity (MME) interface 115, which is a signaling interface between RAN nodes 111 and 112 and MME 121.
In this embodiment, the CN 120 includes an MME 121, an S-GW 122, a Packet Data Network (PDN) gateway (P-GW) 123, and a Home Subscriber Server (HSS) 124. The MME 121 may be similar in function to the control plane of a conventional serving General Packet Radio Service (GPRS) support node (SGSN). MME 121 may manage mobility aspects in the access such as gateway selection and tracking area list management. HSS 124 may include a database for network users including subscription-related information for supporting network entity handling communication sessions. The CN 120 may include one or several HSS 124 depending on the number of mobile users, the capacity of the device, the organization of the network, etc. For example, the HSS 124 can provide support for routing/roaming, authentication, authorization, naming/addressing resolution, location dependencies, and the like.
S-GW 122 may terminate S1 interface 113 towards RAN 110 and route data packets between RAN 110 and CN 120. In addition, the S-GW 122 may be a local mobility anchor for inter-RAN node handover and may also provide an anchor for inter-3 GPP mobility. Other responsibilities may include lawful interception, billing, and some policy enforcement.
The P-GW 123 may face the PDN termination SGi interface. The P-GW 123 may route data packets between the EPC network 123 and an external network, such as a network that includes an application server 130 (alternatively referred to as an Application Function (AF)), via an Internet Protocol (IP) interface 125. In general, the application server 130 may be an element that provides applications (e.g., UMTS Packet Service (PS) domain, LTE PS data service, etc.) that use IP bearer resources with the core network. In this embodiment, P-GW 123 is shown communicatively coupled to application server 130 via IP communication interface 125. The application server 130 can also be configured to support one or more communication services (e.g., voice over internet protocol (VoIP) sessions, PTT sessions, group communication sessions, social networking services, etc.) of the UEs 101 and 102 via the CN 120.
The P-GW 123 may also be a node for policy enforcement and charging data collection. Policy and Charging Rules Function (PCRF) 126 is a policy and charging control element of CN 120. In a non-roaming scenario, there may be a single PCRF in a Home Public Land Mobile Network (HPLMN) associated with an internet protocol connectivity access network (IP-CAN) session of the UE. In a roaming scenario with local traffic bursts, there may be two PCRFs associated with the IP-CAN session of the UE: a home PCRF (H-PCRF) within the HPLMN and a visited PCRF (V-PCRF) in a Visited Public Land Mobile Network (VPLMN). PCRF 126 may be communicatively coupled to application server 130 via P-GW 123. The application server 130 may signal the PCRF 126 to indicate the new traffic flow and select the appropriate quality of service (QoS) and charging parameters. PCRF 126 may employ appropriate Traffic Flow Templates (TFTs) and QoS type identifiers (QCIs) to specify the rules in a Policy and Charging Enforcement Function (PCEF) (not shown) that begins QoS and charging specified by application server 130.
Fig. 2 illustrates example components of a device 200 in accordance with certain embodiments. In some embodiments, device 200 may include application circuitry 202, baseband circuitry 204, radio Frequency (RF) circuitry 206, front End Module (FEM) circuitry 208, one or more antennas 210, and Power Management Circuitry (PMC) 212 coupled together at least as shown. The illustrated components of the device 200 may be included in a UE or RAN node. In some embodiments, the device 200 may include fewer elements (e.g., the RAN node may not utilize the application circuitry 202, but instead include a processor/controller to process IP data received from the EPC). In some embodiments, device 200 may include additional elements such as memory/storage, displays, cameras, sensors, or input/output (I/O) interfaces. In other embodiments, the components described below may be included in more than one device (e.g., the circuitry may be included separately in multiple devices for a cloud-RAN (C-RAN) implementation).
The application circuitry 202 may include one or more application processors. For example, application circuitry 202 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. A processor may include any combination of general-purpose and special-purpose processors (e.g., graphics processors, application processors, etc.). The processor may be coupled to or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications or operating systems to run on the device 200. In some embodiments, the processor of application circuitry 202 may process IP data packets received from the EPC.
Baseband circuitry 204 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 204 may include one or more baseband processors or control logic to process baseband signals received from the receive signal path of the RF circuitry 206 and to generate baseband signals for the transmit signal path of the RF circuitry 206. The baseband processing circuit 204 may interface with the application circuit 202 for generating and processing baseband signals and for controlling the operation of the RF circuit 206. For example, in some embodiments, the baseband circuitry 204 may include a third generation (3G) baseband processor 204A, a fourth generation (4G) baseband processor 204B, a 5G/NR baseband processor 204C, or other baseband processor(s) 204D for other existing generations, generations under development, or generations to be developed in the future (e.g., second generation (2G), sixth generation (6G), etc.). The baseband circuitry 204 (e.g., one or more of the baseband processors 204A-D) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 206. In other embodiments, some or all of the functionality of the baseband processors 204A-D may be included in modules stored in the memory 204G and executed via the Central Processing Unit (CPU) 204E. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, and the like. In some embodiments, the modulation/demodulation circuitry of baseband circuitry 204 may include Fast Fourier Transform (FFT), precoding, or constellation mapping/demapping functions. In some embodiments, the encoding/decoding circuitry of baseband circuitry 204 may include convolution, tail-biting convolution, turbo, viterbi, or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of the modem and encoder/decoder functions are not limited to these examples and may include other suitable functions in other embodiments.
In some embodiments, the baseband circuitry 204 may include one or more audio Digital Signal Processors (DSPs) 204F. The audio DSP 204F may include elements for compression/decompression and echo cancellation, and may include other suitable processing elements in other embodiments. In some embodiments, components of the baseband circuitry may be suitably combined on a single chip, a single chipset, or disposed on the same circuit board. In some embodiments, some or all of the constituent components of baseband circuitry 204 and application circuitry 202 may be implemented together (e.g., on a system on a chip (SOC)).
In some embodiments, baseband circuitry 204 may provide for communication compatible with one or more radio technologies. For example, in some embodiments, baseband circuitry 204 may support communication with an Evolved Universal Terrestrial Radio Access Network (EUTRAN) or other Wireless Metropolitan Area Network (WMAN), wireless Local Area Network (WLAN), wireless Personal Area Network (WPAN). An embodiment in which the baseband circuitry 204 is configured to support radio communications for multiple wireless protocols may be referred to as a multimode baseband circuitry.
The RF circuitry 206 may enable communication with a wireless network through a non-solid medium and using modulated electromagnetic radiation. In various embodiments, RF circuitry 206 may include switches, filters, amplifiers, and the like to facilitate communication with a wireless network. The RF circuitry 206 may include a receive signal path that may include circuitry for down-converting RF signals received from the FEM circuitry 208 and providing baseband signals to the baseband circuitry 204. RF circuitry 206 may also include a transmit signal path that may include circuitry for up-converting baseband signals provided by baseband circuitry 204 and providing RF output signals to FEM circuitry 208 for transmission.
In some embodiments, the receive signal path of RF circuit 206 may include a mixer circuit 206A, an amplifier circuit 206B, and a filter circuit 206C. In some embodiments, the transmit signal path of RF circuit 206 may include filter circuit 206C and mixer circuit 206A. The RF circuit 206 may also include a synthesizer circuit 206D for synthesizing frequencies used by the mixer circuit 206A of the receive signal path and the transmit signal path. In some embodiments, the mixer circuit 206A of the receive signal path may be configured to down-convert the RF signal received from the FEM circuit 208 based on the synthesized frequency provided by the synthesizer circuit 206D. The amplifier circuit 206B may be configured to amplify the down-converted signal and the filter circuit 206C may be a Low Pass Filter (LPF) or a Band Pass Filter (BPF) configured to remove unwanted signals from the down-converted signal to produce an output baseband signal. The output baseband signal may be provided to baseband circuitry 204 for further processing. In some embodiments, the output baseband signal may be a zero frequency baseband signal, but this is not required. In some embodiments, the mixer circuit 206A of the receive signal path may comprise a passive mixer, although the scope of the embodiments is not limited in this respect.
In some embodiments, the mixer circuit 206A of the transmit signal path may be configured to upconvert the input baseband signal based on the synthesized frequency provided by the synthesizer circuit 206D to generate an RF output signal for the FEM circuit 208. The baseband signal may be provided by baseband circuitry 204 and may be filtered by filter circuitry 206C.
In some embodiments, the mixer circuit 206A of the receive signal path and the mixer circuit 206A of the transmit signal path may comprise two or more mixers and may be arranged for quadrature down-conversion and up-conversion, respectively. In some embodiments, the mixer circuit 206A of the receive signal path and the mixer circuit 206A of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., hartley image rejection). In some embodiments, the mixer circuit 206A and the mixer circuit 206A of the receive signal path may be arranged for direct down-conversion and direct up-conversion, respectively. In some embodiments, the mixer circuit 206A of the receive signal path and the mixer circuit 206A of the transmit signal path may be configured for superheterodyne operation.
In some embodiments, the output baseband signal and the input baseband signal may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternative embodiments, the output baseband signal and the input baseband signal may be digital baseband signals. In these alternative embodiments, the RF circuitry 206 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry, and the baseband circuitry 204 may include a digital baseband interface to communicate with the RF circuitry 206.
In some dual mode embodiments, separate radio IC circuits may be provided for processing the signals for each spectrum, although the scope of the embodiments is not limited in this respect.
In some embodiments, synthesizer circuit 206D may be a fractional-N synthesizer or a fractional N/n+1 synthesizer, although the scope of embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuit 206D may be a delta sigma synthesizer, a frequency multiplier, or a synthesizer including a phase locked loop with a frequency divider.
Synthesizer circuit 206D may be configured to synthesize an output frequency for use by mixer circuit 206A of RF circuit 206 based on the frequency input and the divider control input. In some embodiments, synthesizer circuit 206D may be a fractional N/N+1 synthesizer.
In some embodiments, the frequency input may be provided by a Voltage Controlled Oscillator (VCO), but this is not required. The divider control input may be provided by the baseband circuitry 204 or the application processor 202, depending on the desired output frequency. In some embodiments, the divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the application processor 202.
The synthesizer circuit 206D of the RF circuit 206 may include a frequency divider, a Delay Locked Loop (DLL), a multiplexer, and a phase accumulator. In some embodiments, the frequency divider may be a dual-mode frequency divider (DMD) and the phase accumulator may be a Digital Phase Accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by N or n+1 (e.g., based on a carry) to provide a fractional divide ratio. In some example embodiments, the DLL may include a set of cascaded, tunable delay cells, a phase detector, a charge pump, and a D-type flip-flop. In these embodiments, the delay element may be configured to decompose the VCO period into Nd equal phase packets, where Nd is the number of delay cells in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.
In some embodiments, synthesizer circuit 206D may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with a quadrature generator and a divider circuit to generate a plurality of signals having a plurality of different phases from one another at the carrier frequency. In some embodiments, the output frequency may be an LO frequency (fLO). In some embodiments, the RF circuit 206 may include an IQ/polarity converter.
FEM circuitry 208 may include a receive signal path that may include circuitry configured to operate on RF signals received from one or more antennas 210, amplify the received signals, and provide an amplified version of the received signals to RF circuitry 206 for further processing. FEM circuitry 208 may also include a transmit signal path, which may include circuitry configured to amplify signals provided by RF circuitry 206 for transmission by one or more of the one or more antennas 210. In various embodiments, amplification through the transmit or receive signal paths may be accomplished in only RF circuit 206, only FEM208, or both RF circuit 206 and FEM 208.
In some embodiments, FEM circuitry 208 may include TX/RX switches to switch between transmit and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include an LNA to amplify the received RF signal and provide the amplified received RF signal as an output (e.g., to the RF circuitry 206). The transmit signal path of FEM circuitry 208 may include: a Power Amplifier (PA) to amplify an input RF signal (e.g., provided by RF circuitry 206); and one or more filters to generate RF signals for subsequent transmission (e.g., via one or more of the one or more antennas 210).
In some embodiments, PMC212 may manage the power provided to baseband circuitry 204. In particular, the PMC212 may control power supply selection, voltage scaling, battery charging, or DC-to-DC conversion. PMC212 may often be included when device 200 is capable of being powered by a battery (e.g., when the device is included in a UE). PMC212 may improve power conversion efficiency while providing desired implementation size and heat dissipation characteristics.
Although fig. 2 shows PMC 212 coupled only with baseband circuitry 204, in other embodiments PMC 212 may additionally or alternatively be coupled with other components, such as, but not limited to application circuitry 202, RF circuitry 206, or FEM208, and perform similar power management operations with respect to other components.
In some embodiments, PMC 212 may control or otherwise be part of various power saving mechanisms of device 200. For example, if the device 200 is in an rrc_connected state (rrc_connected) in which it is still Connected to the RAN node because it wants to receive traffic for a short time, it may enter a state known as discontinuous reception mode (DRX) after an inactivity period. During this state, the device 200 may be powered down for a brief interval, thus saving power.
If no data traffic is active for an extended period of time, the device 200 may transition to the RRC idle state. In the RRC idle state, the device 200 may disconnect from the network and avoid performing operations such as channel quality feedback, handover, etc. The device 200 may enter a very low power state and perform paging, where the device 200 may periodically wake up to listen to the network and then power down again. To receive the data, the device 200 may transition back to the rrc_connected state.
The additional power saving mode may allow the period of device unavailability to the network to be longer than the paging interval (ranging from a few seconds to a few hours). During this time, the device is completely inaccessible to the network and may be completely powered down. Any data transmitted during this period will create a large delay and the delay is assumed to be acceptable.
The processor of the application circuitry 202 and the processor of the baseband circuitry 204 may be used to execute units of one or more instances of the protocol stack. For example, the processor of baseband circuitry 204 (alone or in combination) may be used to perform layer 3, layer 2, or layer 1 functions, while the processor of application circuitry 204 may utilize data (e.g., packet data) received from these layers and further perform layer 4 functions (e.g., transmission Communication Protocol (TCP) and User Datagram Protocol (UDP) layers). As mentioned herein, layer 3 may include a Radio Resource Control (RRC) layer, which will be described in further detail below. As mentioned herein, layer 2 may include a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, and a Packet Data Convergence Protocol (PDCP) layer, which will be described in further detail below. As mentioned herein, layer 1 may include a Physical (PHY) layer of a UE/RAN node, as will be described in further detail below.
Fig. 3 illustrates an example interface of baseband circuitry in accordance with certain embodiments. As discussed above, the baseband circuitry 204 of fig. 2 can include processors 204A-XT04E and memory 204G used by the processors. Processors 204A-XT04E may each include a memory interface 304A-XU04E to transmit and receive data to and from memory 204G, respectively.
The baseband circuitry 204 may also include one or more interfaces to communicatively couple to other circuits/devices, such as a memory interface 312 (e.g., an interface to transmit/receive data to/from memory external to the baseband circuitry 204), an application circuit interface 314 (e.g., an interface to transmit/receive data to/from the application circuitry 202 of fig. 2), an RF circuit interface 316 (e.g., an interface to transmit/receive data to/from the RF circuitry 206 of fig. 2), a wireless hardware connection interface 318 (e.g., an interface to transmit/receive data to/from a Near Field Communication (NFC) component, a bluetooth component (e.g., bluetooth low energy), a Wi-Fi component, and other communication components), and a power management interface 320 (e.g., an interface to transmit/receive power or control signals to/from the PMC 212).
Fig. 4 is an illustration of a control plane protocol stack in accordance with some embodiments. In this embodiment, the control plane 400 is shown as a communication protocol stack between the UE 101 (or alternatively, UE 102), the RAN node 111 (or alternatively, RAN node 112), and the MME 121.
The PHY layer 401 may send or receive information used by the MAC layer 402 over one or more air interfaces. PHY layer 401 may also perform link adaptation or Adaptive Modulation and Coding (AMC), power control, cell search (e.g., for initial synchronization and handover purposes), and other measurements used by higher layers such as RRC layer 405. PHY layer 401 may also perform error detection for the transport channels, forward Error Correction (FEC) encoding/decoding of the transport channels, modulation/demodulation of the physical channels, interleaving, rate matching, mapping to the physical channels, and multiple-input multiple-output (MIMO) antenna processing.
The MAC layer 402 may perform mapping between logical channels and transport channels, multiplexing MAC Service Data Units (SDUs) from one or more logical channels to Transport Blocks (TBs) to be delivered to the PHY via the transport channels, demultiplexing MAC SDUs from one or more logical channels from Transport Blocks (TBs) to be delivered from the PHY via the transport channels, multiplexing MAC SDUs to TBs, scheduling information reporting, error correction by hybrid automatic repeat request (HARQ), and logical channel prioritization.
The RLC layer 403 may operate in a variety of modes of operation including: transparent Mode (TM), unacknowledged Mode (UM), and Acknowledged Mode (AM). The RLC layer 403 may perform transmission of upper layer Protocol Data Units (PDUs), error correction by automatic repeat request (ARQ) for AM data transmission, and concatenation, segmentation and reassembly of RLC SDUs for UM and AM data transmission. The RLC layer 403 may also perform re-segmentation of RLC data PDUs for AM data transfer, re-ordering RLC data PDUs for UM and AM data transfer, detecting duplicate data for UM and AM data transfer, discarding RLC SDUs for UM and AM data transfer, detecting protocol errors for AM data transfer, and performing RLC re-establishment.
The PDCP layer 404 may perform header compression and decompression of IP data, maintain PDCP Sequence Numbers (SNs), perform sequential delivery of upper layer PDUs when reconstructing lower layers, eliminate duplication of lower layer SDUs when reconstructing lower layers for radio bearers mapped on RLC AMs, encrypt and decrypt control plane data, perform integrity protection and integrity verification of control plane data, control timer-based data dropping, and perform security operations (e.g., ciphering, deciphering, integrity protection, integrity verification, etc.).
The primary services and functions of the RRC layer 405 may include broadcasting of system information (e.g., included in a Master Information Block (MIB) or System Information Block (SIB) associated with a non-access stratum (NAS)), broadcasting of system information associated with an Access Stratum (AS), paging, establishment, maintenance and release of RRC connections between UEs and E-UTRAN (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), establishment, configuration, maintenance and release of point-to-point radio bearers, security functions including key management, inter-Radio Access Technology (RAT) mobility, and measurement configuration of UEs. The MIB and SIB may include one or more cells (IEs), each of which may include a separate data field or data structure.
The UE 101 and the RAN node 111 may utilize a Uu interface (e.g., an LTE-Uu interface) to exchange control plane data via a protocol stack including a PHY layer 401, a MAC layer 402, an RLC layer 403, a PDCP layer 404, and an RRC layer 405.
The non-access stratum (NAS) protocol 406 forms the highest layer of the control plane between the UE 101 and the MME 121. The NAS protocol 406 supports mobility and session management procedures for the UE 101 to establish and maintain an IP connection between the UE 101 and the P-GW 123.
The S1 application protocol (S1-AP) layer 415 may support the functionality of the S1 interface and include basic procedures (EPs). An EP is an interworking unit between the RAN node 111 and the CN 120. The S1-AP layer traffic may include two groups: UE-associated traffic and non-UE-associated traffic. The functions performed by these services include, but are not limited to: E-UTRAN radio access bearer (E-RAB) management, UE capability indication, mobility, NAS signaling transport, RAN Information Management (RIM), and configuration transport.
A Stream Control Transmission Protocol (SCTP) layer (alternatively referred to as SCTP/IP layer) 414 may ensure reliable transfer of signaling messages between RAN node 111 and MME 121 based in part on the IP protocols supported by IP layer 413. The L2 layer 412 and the L1 layer 411 may refer to communication links (e.g., wired or wireless) used by the RAN node and MME to exchange information.
RAN node 111 and MME 121 may exchange control plane data via a protocol stack comprising L1 layer 411, L2 layer 412, IP layer 413, SCTP layer 414, and S1-AP layer 415 using an S1-MME interface.
Fig. 5 is an illustration of a user plane protocol stack in accordance with some embodiments. In this embodiment, user plane 500 is shown as a communication protocol stack between UE 101 (or alternatively, UE 102), RAN node 111 (or alternatively, RAN node 112), S-GW 122, and P-GW 123. The user plane 500 may use at least some of the same protocol layers as the control plane 400. For example, the UE 101 and the RAN node 111 may exchange user plane data via a protocol stack including a PHY layer 401, a MAC layer 402, an RLC layer 403, a PDCP layer 404 using a Uu interface (e.g., an LTE-Uu interface).
A General Packet Radio Service (GPRS) tunneling protocol for the user plane (GTP-U) layer 504 may be used to carry user data within the GPRS core network and between the radio access network and the core network. For example, the transmitted user data can be in any of IPv4, IPv6, or PPP formats. The UDP and IP security (UDP/IP) layer 503 may provide a checksum of data integrity for addressing port numbers of different functions at the source and destination, as well as encryption and authentication of selected data streams. RAN node 111 and S-GW 122 may utilize the S1-U interface to exchange user plane data via a protocol stack comprising L1 layer 411, L2 layer 412, UDP/IP layer 503, and GTP-U layer 504. The S-GW 122 and the P-GW 123 may exchange user plane data via a protocol stack including an L1 layer 411, an L2 layer 412, a UDP/IP layer 503, and a GTP-U layer 504 using an S5/S8a interface. As discussed above with respect to fig. 4, the NAS protocol supports mobility and session management procedures for the UE 101 to establish and maintain an IP connection between the UE 101 and the P-GW 123.
Fig. 6 is a block diagram illustrating components capable of reading instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and performing any one or more of the methods discussed herein, according to certain example embodiments. In particular, FIG. 6 shows a graphical representation of a hardware resource 600 including one or more processors (or processor cores) 610, one or more memory/storage devices 620, and one or more communication resources 630, each of which may be communicatively coupled via a bus 640. For embodiments in which node virtualization (e.g., NFV) is utilized, the hypervisor 602 can be executed to provide an execution environment for one or more network slices/sub-slices to utilize the hardware resources 600.
The processor 610 (e.g., a Central Processing Unit (CPU), a Reduced Instruction Set Computing (RISC) processor, a Complex Instruction Set Computing (CISC) processor, a Graphics Processing Unit (GPU), a Digital Signal Processor (DSP) such as a baseband processor, an Application Specific Integrated Circuit (ASIC), a Radio Frequency Integrated Circuit (RFIC), another processor, or any suitable combination thereof) may include, for example, a processor 612 and a processor 614.
Memory/storage 620 may include main memory, disk storage, or any suitable combination thereof. Memory/storage 620 may include, but is not limited to, any type of volatile or non-volatile memory, such as Dynamic Random Access Memory (DRAM), static Random Access Memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid state memory, and the like.
Communication resources 630 may include interconnections or network interface components or other suitable devices to communicate with one or more peripheral devices 604 or one or more databases 606 via network 608. For example, the communication resources 630 may include wired communication components (e.g., for coupling via a Universal Serial Bus (USB)), cellular communication components, NFC components, bluetooth components (e.g., bluetooth low energy), wi-Fi components, and other communication components.
The instructions 650 may include software, programs, applications, applets, apps, or other executable code for causing at least any one of the processors 610 to perform any one or more of the methods discussed herein. The instructions 650 may reside, completely or partially, within at least one of the processors 610 (e.g., within a cache memory of the processor), within the memory/storage device 620, or within any suitable combination thereof. In some embodiments, instructions 650 may reside on a tangible, non-volatile communication device-readable medium, which may comprise a single medium or multiple media. Further, any portion of instructions 650 may be transferred from any combination of peripherals 604 or databases 606 to hardware resource 600. Accordingly, the memory of the processor 610, the memory/storage 620, the peripherals 604, and the database 606 are examples of computer readable and machine readable media.
As described above, with the advent of NR systems, other types of communication are currently being developed in addition to those developed for 4G systems. This type of communication includes URLLC and enhanced mobile broadband (eMBB) communications. URLLC can have very stringent delay limits of 0.5-1ms (compared to the more normal >4ms delay). Such limitations may result in uplink transmissions supporting dynamic scheduling and unlicensed transmissions. These transmissions may take advantage of the following: transmission of a Scheduling Request (SR) from a UE to a gNB on a PUCCH to schedule Uplink (UL) resources for new transmissions from the UE is eliminated, and grant from the gNB to the UE on a PDCCH to access the resources is eliminated.
Fig. 7A illustrates grant-based uplink transmissions in accordance with certain embodiments; fig. 7B illustrates unlicensed uplink transmissions in accordance with certain embodiments. The transmission may be in an FDD system based on mini-slots of 0.071 ms. By using dynamically scheduled uplink and unlicensed transmissions, the delay goal can be achieved within about 99.999%. As shown in fig. 7A, grant-based uplink transmission 710 may be triggered by a UE transmitting SR712 to the gNB on the UL channel to indicate that the UE has data to send to the gNB. The gNB may respond by transmitting an grant 714 to the UE on a Downlink (DL) channel on a later predetermined amount of time (e.g., 2 subframes). Grant 714 may indicate the timing of UL transmissions, and UL channels to be used. The UE may respond to receiving grant 714 by transmitting data 716 on an allocated UL channel (shown in fig. 7A as the same UL channel as the SR712 was transmitted). The gNB may then send another grant or ACK/NACK 718. In contrast, in fig. 7B, unlicensed UL transmission 720 may include only the UE transmitting data on a predetermined UL channel (e.g., as provided in RRC signaling). The gNB may send an ACK/NACK in response to the data. Similar to fig. 7a, the ue may periodically transmit data and the gNB responds with an ACK/NACK.
URLLC can relate to two general types of traffic: periodic and sporadic. For periodic traffic (such as reference signals and reporting transmissions), the arrival time and packet size may be known to the gNB. In this case, an unlicensed transmission scheme with orthogonal resource reservation may be optimal. For sporadic traffic, messages can be generated at random times, with generally unpredictable packet generation rates. In this case, reserving resources in an orthogonal manner for each associated user may result in unsatisfactory resource utilization and system capacity. Non-orthogonal (contention-based) unlicensed resource allocation may provide better resource utilization for sporadic types of traffic. However, care should be taken to design unlicensed resource allocation to meet the above-described reliability of URLLC. For example, semi-static unlicensed transmission scheduling (SPS) may not be appropriate for NR URLLC traffic, due to periodic resource reservations and forced UE transmissions, even though the UE has no data to transmit. Furthermore, SPS may employ DCI activation and deactivation (layer 1 signaling), as opposed to unlicensed resource allocation that can be used immediately by UEs once scheduled; that is, the transmission by the UE using unlicensed resource allocation may be without layer 1 signaling in the UE. Alternatively, contention-based unlicensed transmission with random resource selection may be used, but reliability targets may not be guaranteed due to uncontrolled interference and the probability of persistent collisions.
Thus, a framework is provided below with well controlled resource configuration and adaptation for unlicensed transmission, including resource configuration, signaling, and retransmission schemes. These schemes may provide ultra-reliable and spectrally efficient operation for unlicensed uplink transmission schemes. In some embodiments, these and other concepts may also be applied to grant-based uplink operations or a combination of grant-free and grant-based schemes.
Fig. 8 illustrates unlicensed uplink transmissions in accordance with certain embodiments. Fig. 8 may indicate a frequency-time resource configuration 800 that is notified by the gNB shown in one or more of fig. 1-6 to the UE shown in one or more of fig. 1-6. As described above, the gNB may send an indication of the resource configuration 800 in control signaling, such as RRC signaling. The resource configuration 800 may include a transmission resource pool 808. The transmission resource pool 808 may be a subset of resources from a common set of transmission resources (e.g., from all uplink shared channel resources). In various embodiments, the transmission resource pool 808 may be UE-specific, UE group-specific (for a particular UE group associated with a particular group ID), or cell-specific. As discussed in more detail below, the transmission resource pool 808 may be used to allocate exclusive or partially overlapping resources for unlicensed transmissions in a cell, or to organize frequency/time reuse among different cells or different portions of a cell (e.g., cell center and cell edge). One of the IEs in RRC signaling may be used to provide the active carrier for the bitmap, although other IEs may be used to provide the carrier range.
The transmission resource pool 808 may contain one or more frequency resource units 802 and one or more time resource units 804. The frequency resource unit 802 is the smallest part of the logical frequency band that is assumed to be a single frequency resource. For example, the frequency resource units 802 may be measured in Physical Resource Blocks (PRBs). The logical to physical resource mapping may be distributed or centralized in frequency. The time resource unit 804 is the smallest portion of time that is assumed to be a single time resource. For example, in different embodiments, the duration granularity of the time resource unit 804 may be a mini-slot, a set of OFDM symbols, a slot, or a subframe. The transmission resource pool 808 may contain one or more transmission resource units. The transmission resource units may be schedulable time-frequency resource units. One frequency resource unit 802 allocated in one time resource unit 804 may constitute the smallest transmission resource unit. A set of transport resource units within the transport resource pool 808 may be used for transport block transmission and retransmission. The set of transmission resource units may be referred to as a transmission pattern (pattern) 806 and may be UE-specific or UE-group specific. One or more transmission patterns 806 for one or more UEs or groups of UEs may exist in a single transmission resource pool 808. As shown in fig. 8, the transmission pattern 806 may include the same number of frequency resource units 802 and/or time resource units 804, but in other embodiments the number of one or both may differ between the transmission patterns 806. Similarly, the transmission patterns 806 may be arranged in the same frequency resource unit 802 or time resource unit 804, but at least one may be different for different transmission patterns 806.
The resource pool configuration may be based on determining transmission resources for each time instant. In some embodiments, a bitmap approach may be used for frequency domain resource pool configuration; fig. 9 illustrates bitmap based allocation in accordance with certain embodiments. The bitmap-based allocation may indicate a frequency-time resource configuration used by the gNB shown in one or more of fig. 1-6 for one or more of fig. 1-6. As shown in fig. 9, one or more bit strings may be used to determine the logical frequency resources allocated to a particular resource pool. The number of bits for each frequency bit string may be less than or equal to the number of resources in the transmission resource pool. In some embodiments, the bit strings may be of equal length, while in other embodiments, the bit strings (e.g., for indicating a time pattern) may be different. For example, as shown in fig. 9, "0" in a particular position in the bit string may indicate that a resource is not allocated for transmission by the UE, and "1" may indicate that a resource has been allocated for transmission by the UE.
In another embodiment, the resource pool configuration may be indicated by a starting frequency resource unit index and a plurality of consecutive resource units allocated to a particular resource pool. In addition, the resource pool configuration may span multiple subbands. In one example, the end index may be used to indicate where the second portion of the resource pool ends, thus providing two subbands (with the same number of consecutive resource units) in the transmission resource pool. Each subband may contain the same number of frequency resource units. In some embodiments, the transmission pattern may be indicated by a plurality of start and a plurality of consecutive frequency resource units. The number of consecutive frequency resource units may be different for different starting frequency resource units. In addition, the start and/or number of consecutive frequency resource units may be different for different time resource units.
Alternatively, the resource pool may be configured for all frequency resources. In this case, access to the frequency resources may be controlled by a transmission pattern.
Similarly, a bitmap approach may be used for time domain resource pool configuration. As shown in fig. 9, the bit string may additionally or alternatively be used to determine the time resources allocated to a particular resource pool. The mapping of the bitmap to the slots or mini-slots or OFDM symbol groups indicated by the respective bits is performed by the gNB using a modulo operation of the bitmap size. An offset (e.g., system frame number zero) relative to the anchor instant may be configured for mapping of the bitmap. The individual bits may have the same size (e.g., slots) as the frequency map, or may have a different size (e.g., the frequency bitmap may be a subframe).
Alternatively, the time domain resource pool configuration may use a periodic equation method. In this case, a conventional mapping rule may be used, which may be described by an offset, the number of consecutive time resource units, and a period. For example, the resource pool including each second mini-slot of the slots may be indicated by the number of units in the case of an offset of 0 or 1, by period 2, and by 1.
In some embodiments, the resource pool may include all available time resources in the uplink spectrum. In this case, access to time resources may be controlled by a transmission pattern configured to a specific UE.
The bitmap approach may be able to provide the best tradeoff between signaling overhead and flexibility. The bitmap approach may signal frequency and/or time resources similar to the signaling of an Almost Blank Subframe (ABS) pattern or a pool of side link resources. In some embodiments, the resource pool configuration may be a semi-static parameter of the cell. When semi-static parameters, the resource pool configuration may be indicated in one or more IEs of an RRC message, such as an RRC connection reconfiguration (RRCConnectionReconfiguration) message. In some embodiments, both system information and UE-specific RRC messages may be used. After reception, the UE may store the bit string (or periodic equation, depending on the method) in memory. In some embodiments, the gNB may reconfigure the transmission parameters of the UE after the UE does not successfully receive the transport block.
Different cells may be configured with a set of resource pools, which may be different. In general, the configuration of the pool may be left to the gNB implementation and vendor specific inter-cell optimization. However, where the gNBs from different vendors operate nearby, inter-gNB communication protocols such as the X2-AP interface may be used to coordinate the configuration of the pool. In this case, the resource pool configuration may be exchanged using the X2-AP message. This may be desirable for UEs at the cell edge or UEs in a network with multiple small cells.
As described above, the transmission resource pattern configurations within different transmission resource pools may be different. For URLLC, two types of transmission patterns can be applied to different situations: orthogonal Transmission Patterns (OTP) (type 1 transmission patterns) and quasi-orthogonal transmission patterns (QTP) (type 2 transmission patterns). The OTP may be a set of transmission patterns that do not overlap each other. The group may be cell specific or cell group specific. In some embodiments, the cell-specific or cell group-specific transmission pattern may be located within the same transmission resource pool as the at least one other gNB. This type of pattern may provide a completely orthogonal resource allocation between associated UEs if there are a sufficient number of resources and a relatively small number of UEs. In QTP, each pattern may overlap with one or more other patterns. In some embodiments, the overlap order N (i.e., overlap with up to N resources of other patterns) may be limited to a small value, e.g., 1 or 2, where NF -1 may be the maximum value. Note that if n=0, the set becomes a type-1 transmission mode. In some embodiments, when a high N is used, the gNB may use interference cancellation or rejection techniques.
The discussion of patterns can be divided into frequency domain patterns and time domain patterns. Either or both of OTP or QTP may be used. OTP may be used when there are sufficient resources and there are relatively few UEs, which may be provided in an orthogonal manner. QTP may have more patterns than OTP and thus may be used to increase resource utilization and spectral efficiency for unlicensed transmission of sporadic traffic. Potential collisions between patterns of different UEs transmitted simultaneously can be resolved by the gNB reception process and retransmission scheduling.
The frequency domain transmission pattern may be defined by a variable: nF -number of frequency resource units in the transmission resource pool, and KF -number of frequency resource units in the transmission pattern. The number of orthogonal patterns may beThe number of quasi-orthogonal patterns with up to KF -1 overlapping resources may be nchoosek (NF,KF). As an example, the transmission resource pool size may be 24 PRBs. If the frequency resource unit is 3 PRBs, there are NF =8 units in the transmission resource pool. If each transmission pattern has two resource units, KF =2. In this case, the number of orthogonal patterns is 4, and the number of quasi-orthogonal patterns is 28, as illustrated in table 1 below.
Table 1: frequency domain transmission pattern with NF =8 and KF =2
A set of frequency domain patterns may be configured to the UE by the gNB using RRC signaling. Different cells and/or UEs may have different sets of patterns. A set of different numbers of KF may be configured to a UE depending on the channel quality and traffic requirements of each UE. For example, a UE with a larger data rate may be provided with a pattern having a larger KF than a UE with a small data rate. Rules for selecting one pattern of the set may be defined and controlled by the gNB.
Similarly, the time domain transmission pattern may be an OTP or QTP. Alternatively, the default scenario of the time domain transmission pattern may be that each time unit in the transmission resource pool is available when the packet arrives at the UE, and possible collisions are resolved by frequency domain partitioning. However, OTP or QTP time domain patterns may be useful for randomizing interference and collisions in intra-cell and inter-cell communications. The function describing the time domain pattern may be counted from the first slot or mini-slot in a subframe or frame. The time domain pattern may be configured by a bitmap or an equation featuring periodic occurrences of period values, offsets, and slot/mini-slot numbers in the occasion.
The time pattern may also indicate resources for initial transmission and retransmission. In this case, the round trip time of ACK/NACK feedback or retransmission grant (DCI) can be considered. Fig. 10 illustrates a time pattern of a single transmission prior to ACK/NACK feedback (or new grant) in accordance with certain embodiments. The time pattern may illustrate an initial packet (data) transmission 1002 by the UE illustrated in one or more of fig. 1-6 and a single ACK/NACK 1004 sent by the gNB illustrated in one or more of fig. 1-6. Note that packets and ACK/NACKs as other transmissions may be generated and encoded at the source (whether UE or gNB) and decoded and further processed at the destination (whether gNB or UE), all by processing circuitry in the respective device.
In fig. 10, it may be assumed that one mini-slot is used for processing initial transmission, one mini-slot is used for ACK/NACK/grant transmission, and one mini-slot is used for processing at the UE. In general, there may be 3 minislot gaps between the initial transmission 1002 and the feedback-based retransmission 1004. Under these conditions, the time pattern may have at least 3 zeros, provided that there is no automatic repetition/retransmission, i.e. the repetition/retransmission is not based on feedback. In fig. 10, a single transmission may be allowed before an ACK/NACK is received.
However, in some cases, it may be desirable to increase the link budget of FIG. 10. Fig. 11 illustrates a time pattern of bundled transmissions with single ACK/NACK feedback in accordance with certain embodiments. The time pattern may show an initial packet transmission by the UE shown in one or more of fig. 1-6, as well as a single ACK/NACK sent by the gNB shown in one or more of fig. 1-6. In FIG. 11, like TTI bundling and unlike FIG. 10, multiple (K, where K.gtoreq.1) automatic retransmissions can be scheduled prior to the time of feedback reception to improve the link budget. Thus, the initial transmission and at least one retransmission may occur before receiving an ACK/NACK/grant corresponding to the initial packet transmission.
In some cases, multiple ACK/NACKs/grants may be used in response to an initial transmission to improve the link budget of the ACK/NACK/grants, rather than a single ACK/NACK/grant transmission. Fig. 12 illustrates a time pattern for bundled transmissions with multiple ACK/NACK feedback in accordance with certain embodiments. The time pattern may illustrate initial packet transmissions for the UE shown in one or more of fig. 1-6, as well as a single ACK/NACK sent by the gNB shown in one or more of fig. 1-6. As shown, instead of sending feedback only after the last transmission within K retransmissions, the gNB may transmit a single ACK/NACK/grant transmission after each UE transmission. If there is no limitation on DL ACK/NACK/DCI reliability and capacity, multiple ACK/NACK/grant transmissions may be used.
In some embodiments, K retransmissions may not be consecutive to the initial transmission. This may be used to further randomize potential collisions and interference between UEs. As discussed above, randomization may be controlled by a time domain transmission pattern component.
In some embodiments, the value of K may be individually configurable for initial transmission and retransmission. The initial value K may be determined by the gNB based on, for example, quality of service (QoS) parameters, such as a channel quality estimate and a target block error rate (BLER) or Packet Error Rate (PER), which may be higher than the target reliability of URLLC traffic. In other words, K may be determined assuming a specific BLER, e.g. a BLER of 1% or 10%. The value of K for retransmission (K1,K2, a.) can be calculated to consider K0 TTIs that have been sent to meet reliability. In some embodiments, the value K may be dynamically signaled in the DCI for retransmission as well as transmission patterns, as discussed above. The retransmission parameters in this case may be adjusted based on instantaneous channel and interference measurements performed by the UE during the initial transmission.
In some embodiments, a dedicated DCI format can be defined to carry information to reconfigure unlicensed transmission parameters. The size of the DCI may be minimized to indicate only a limited set of changed transmission parameters and/or offsets relative to previous parameters, thus improving the reliability of such compact DCI reception.
Alternatively, for unlicensed transmission, the set of K values ([ K0,K1,K2,...KM ]) for each of the M possible retransmissions may be configured in advance using RRC messages or higher layer signaling in the MAC Control Element (CE). This may have lower spectral efficiency than dynamic adaptation to channel conditions, but may give up signaling of DCI for retransmission. In this case, NACK signaling may be sufficient. Note that transmission parameters other than the K value may be configured for each transmission. These transmission parameters may include modulation, code rate, resource allocation, and power, which may be preconfigured using higher layer signaling.
In order to combine the above frequency and time transmission pattern components, the gNB may allocate an index to the UE of a frequency and time pattern to be used by the UE when the UE has traffic to be transmitted in an unlicensed manner. The allocation of the pattern index may be indicated by the DCI using physical layer signaling, RRC message, or using a combination thereof. For example, RRC may specify a default pattern index, while DCI signaling may override RRC configuration in a dynamic manner. In addition, a jump equation may be defined to change the pattern index over time. A hash function can be applied. The hash function may depend on one or more UE-specific and/or UE-independent variables, such as UE ID, slot/mini-slot index, cell ID. Different cells may have different sets of patterns or different hopping behavior to randomize inter-cell interference. The time pattern may be changed by DCI which schedules retransmissions belonging to the initial transmission in an unlicensed manner.
In some embodiments, the NR uplink unlicensed transmission may include a pool of resources configured for unlicensed uplink transmission and a set of gnbs of quasi-orthogonal transmission patterns. The gNB may also configure the transmission pattern index of the UE and reconfigure the transmission parameters after receiving the transport block is unsuccessful. The resource pool configuration may include frequency domain and time domain resource pool configurations. The frequency domain resource pool configuration may include a bitmap of frequency resources, where a zero indicates that the corresponding unit is not included, and a 1 indicates that the corresponding resource unit is included in the resource pool. The frequency domain resource pool configuration may include a start index, an end index, and a plurality of frequency resource units. The time domain resource pool configuration may include a bitmap of time resources, where zero indicates that the corresponding resource unit is not included, and 1 indicates that the corresponding resource unit is included in the resource pool. The bitmap may repeat within a defined period and start with an offset relative to the anchor moment. The anchor instant may be a system frame number zero. The time domain resource pool configuration may include an offset, a period, and a plurality of resource units in an occasion. The UE transmission pattern may include a frequency domain pattern and a time domain pattern. The frequency domain patterns may be orthogonal to each other. The frequency domain patterns may be quasi-orthogonal to a limited number of overlapping resources between each other. The quasi-orthogonal pattern may include NF elements, where there are KF 1 s, while the others are zero. Different UEs may be configured with different values of KF. Different cells may have different sets of patterns. The time domain pattern may indicate resources for initial transmission and multiple retransmissions. The index of the time and frequency transmission pattern may be signaled to the UE by the gNB in the DCI. The time pattern may be represented by a number K, which may include initial transmission and retransmission, and may be signaled in DCI. The index of the time and frequency transmission pattern may be signaled to the UE by the gNB in an RRC message. The indexes of the initial transmission and retransmission may be configured separately. The transmission pattern may be a function of mini-slot/subframe index, a function of UE identity, and/or a function of cell identity. The resource pool configuration may be exchanged between the gnbs using X2-AP interface messages.
Example
Example 1 is a User Equipment (UE) apparatus, comprising: a memory; and processing circuitry arranged to: decoding control signaling from a gndeb (gNB), the control signaling indicating a transmission pattern for unlicensed uplink transmissions to the gNB, the transmission pattern indicated in the control signal being: at least one frequency domain resource pool configuration including a plurality of Frequency Resource Units (FRUs), and at least one TRU indicated in a time domain resource pool configuration including a plurality of Time Resource Units (TRUs), wherein the frequency domain resource pool configuration and the time domain resource pool configuration are disposed within a resource pool that is a subset of resources from a common set of resources available to the gNB, and wherein the transmission pattern is selected from at least one of a set of Orthogonal Transmission Patterns (OTPs) and a set of quasi-orthogonal transmission patterns (QTPs) in the resource pool, the selection being dependent on a number of UEs served by the eNB and a size of the resource pool; storing a transmission pattern received from the control signaling in a memory; and encoding unlicensed uplink transmissions on the at least one FRU and TRU in the stored transmission pattern for transmission to the gNB.
In example 2, the subject matter of example 1 includes, wherein: at least one of the frequency domain resource pool configuration and the time domain resource pool configuration is indicated in the control message by a corresponding bitmap of resource units of the resource pool, and the processing circuitry is further arranged to determine at least one of the FRUs and TRUs using the bitmap of the at least one of the frequency domain resource pool configuration and the time domain resource pool configuration.
In example 3, the subject matter of examples 1-2 includes, wherein: the frequency domain resource pool configuration is indicated in the control message by: the starting frequency resource unit index indicating the starting FRU, and the number of consecutive FRUs, and the processing circuitry is further arranged to determine the FRU using the starting frequency resource unit index and the number of consecutive FRUs.
In example 4, the subject matter of example 3 includes, wherein: the frequency domain resource pool configuration is further indicated in the control message by an ending frequency resource unit index indicating an ending FRU, the frequency domain resource pool configuration comprising a plurality of subbands of a plurality of consecutive FRUs corresponding to a number of consecutive FRUs, and the processing circuitry is further arranged to determine the FRU using the ending frequency resource unit index.
In example 5, the subject matter of examples 1-4 includes, wherein: the time domain resource pool configuration is periodic, the time domain resource pool configuration being indicated in the control message by an offset, a number of consecutive TRUs and a period, and the processing circuitry is further arranged to determine the TRU using the offset, the number of consecutive TRUs and the period.
In example 6, the subject matter of examples 1-5 includes, wherein: the control signal is a Radio Resource Control (RRC) message.
In example 7, the subject matter of examples 1-6 include, wherein: the resource pool is one of a plurality of cell-specific resource pools.
In example 8, the subject matter of examples 1-7 include, wherein: the transmission pattern is one of a plurality of cell-specific or cell group-specific OTP transmission patterns of the resource pool.
In example 9, the subject matter of examples 1-8 include, wherein: the transmission pattern is one of a plurality of UE-specific QTP transmission patterns of the resource pool.
In example 10, the subject matter of examples 1-9 includes, wherein: the time domain resource pool configuration indicates resources for initial transmission and retransmission, and the TRU for retransmission depends on round trip acknowledgement/negative acknowledgement (ACK/NACK) feedback or time of retransmission grant.
In example 11, the subject matter of example 10 includes, wherein: multiple individually retransmitted TRUs for initial transmission are scheduled before the UE receives ACK/NACK feedback.
In example 12, the subject matter of examples 10-11 include, wherein: the TRU of the multiple bundling retransmissions for the bundled initial transmission is scheduled before the UE receives the ACK/NACK feedback.
In example 13, the subject matter of example 12 includes, wherein: the number of retransmissions within each retransmission bundle depends on at least one quality of service (QoS) parameter.
In example 14, the subject matter of examples 12-13 includes, wherein: the number of retransmissions in each retransmission bundle is indicated together with the transmission pattern in the Downlink Control Information (DCI) for the retransmission.
In example 15, the subject matter of examples 10-14 includes, wherein: before the UE receives the ACK/NACK feedback, each retransmission, and each initial transmission, a plurality of separate neighbor retransmissions for each initial neighbor transmission are scheduled.
In example 16, the subject matter of examples 1-15 includes, wherein the processing circuitry is further configured to: different pattern indexes are periodically decoded, each pattern index configured to indicate a unique time-domain and frequency-domain resource pool configuration.
In example 17, the subject matter of examples 1-16 includes, wherein: the processing circuit includes a baseband processor configured to encode transmissions to the gNB and to decode transmissions from the gNB.
Example 18 is a gndeb (gNB) apparatus, comprising: a memory; and processing circuitry arranged to: determining a transmission pattern of a plurality of User Equipments (UEs), the transmission pattern for unlicensed uplink transmission to a gNB, the transmission pattern being disposed within at least one resource pool that is a subset of resources from a common set of resources available to the gNB, the at least one resource pool comprising a resource pool configuration including a frequency domain resource pool configuration and a time domain resource pool configuration, the transmission pattern of the at least one resource pool selected from at least one of a set of cell-specific or cell group-specific Orthogonal Transmission Patterns (OTPs) or a set of UE-specific quasi-orthogonal transmission patterns (QTPs) in the at least one resource pool; storing the transmission pattern in a memory; encoding control signaling indicating one of the transmission patterns stored in the memory using the frequency domain resource pool configuration and the time domain resource pool configuration for transmission to one of the UEs; and decoding, from the UE, the unlicensed uplink transmission on the one transmission pattern.
In example 19, the subject matter of example 18 includes, wherein: at least one of the frequency domain resource pool configuration or the time domain resource pool configuration is indicated in the control message by a corresponding bitmap of resource units of the resource pool.
In example 20, the subject matter of examples 18-19 include, wherein: the frequency domain resource pool configuration is indicated in the control message by a starting frequency resource unit index indicating a starting Frequency Resource Unit (FRU) and a number of consecutive FRUs.
In example 21, the subject matter of example 20 includes, wherein: the frequency domain resource pool configuration is further indicated in the control message by an ending frequency resource unit index indicating an ending FRU, the frequency domain resource pool configuration comprising a plurality of subbands of a plurality of consecutive FRUs corresponding to the number of consecutive FRUs.
In example 22, the subject matter of examples 18-21 includes, wherein: the time domain resource pool configuration is periodic and is indicated in the control message by an offset, a number of consecutive Time Resource Units (TRUs), and a period.
In example 23, the subject matter of examples 18-22 includes, wherein: the resource pool is one of a plurality of cell-specific resource pools.
In example 24, the subject matter of examples 18-23 includes, wherein the processing circuitry is further configured to: different pattern indexes for a particular UE are periodically encoded, each pattern index configured to indicate unique time-domain and frequency-domain resource pool configurations.
In example 25, the subject matter of example 24 includes, wherein the processing circuitry is further configured to: a hash function is applied to each pattern index prior to transmitting the pattern index, the hash function being dependent on at least one of a UE Identification (ID), a slot or mini-slot index at the time of transmitting the pattern index, or a cell ID of the gNB.
In example 26, the subject matter of examples 24-25 includes wherein: each pattern index is unique to the gNB.
In example 27, the subject matter of examples 18-26 includes, wherein the processing circuitry is further configured to: the frequency domain and time domain resource pool configuration of the gNB and other gNBs is coordinated with other gNBs through X2-AP messages.
Example 28 is a non-transitory computer-readable storage medium storing instructions for execution by one or more processors of a User Equipment (UE) to, when executing the instructions, configure the UE to: receiving a Radio Resource Control (RRC) message from a gnob (gNB), the RRC message indicating a transmission pattern of unlicensed uplink transmissions to the gNB, the transmission pattern being disposed within a resource pool that is a subset of resources of a common set of resources available to the gNB, the resource pool including a frequency domain resource pool configuration and a time domain resource pool configuration indicated in the RRC message, the transmission pattern including at least one of a set of cell-specific or cell group-specific Orthogonal Transmission Patterns (OTPs) in the resource pool, or a set of UE-specific quasi-orthogonal transmission patterns (QTPs); and transmitting an unlicensed uplink transmission to the gNB on the transmission pattern.
In example 29, the subject matter of example 28 includes one of: at least one of a frequency domain resource pool configuration or a time domain resource pool configuration indicated in the RRC message by a corresponding bitmap of resource units in the resource pool, the frequency domain resource pool configuration being indicated in the RRC message by a starting frequency resource unit index indicating a starting Frequency Resource Unit (FRU) and a plurality of consecutive FRUs, or the time domain resource pool configuration being periodic and indicated in the RRC message by an offset, a number of consecutive Time Resource Units (TRUs), and a period.
In example 30, the subject matter of examples 28-29 include, wherein the instructions further configure the one or more processors to configure the UE to: different pattern indexes are periodically decoded, each pattern index being configured to indicate a unique time-domain and frequency-domain resource pool configuration.
Example 31 is at least one machine-readable medium comprising instructions that when executed by processing circuitry cause the processing circuitry to perform operations to implement any one of examples 1-30.
Example 32 is an apparatus comprising means for implementing any of examples 1-30.
Example 33 is a system to implement any of examples 1-30.
Example 34 is a method of implementing any one of examples 1-30.
Although embodiments have been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader scope of the disclosure. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. The accompanying drawings that form a part hereof show by way of illustration, and not of limitation, specific embodiments in which the subject matter may be practiced. The embodiments set forth are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. The detailed description is, therefore, not to be taken in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.
The abstract of the disclosure is provided to conform to 37 c.f.r. ≡1.72 (b) (abstract that requires a quick determination of the nature of the technical disclosure by the reader). This abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing detailed description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment.