Disclosure of Invention
The technical problem to be solved by the present invention is to provide a device discovery method for device-to-device communication, a user equipment, and a network side device, so as to improve the reliability of device-to-device communication.
In order to solve the above technical problem, the present invention discloses a device discovery method for device-to-device communication, comprising:
the method comprises the steps that user equipment receives equipment discovery first configuration signaling sent by network side equipment;
the user equipment determines equipment discovery resources used for equipment discovery signal transmission according to the first configuration signaling, and performs equipment discovery through the equipment discovery resources;
the first configuration signaling is sent in a broadcast mode and at least comprises one or more of the following parameters:
time domain radio resource configuration parameters for indicating device discovery frames and/or subframes;
a frequency domain radio resource configuration parameter for indicating a device discovery band location;
a sequence configuration parameter for indicating a device discovery signal sequence.
Preferably, in the method, the time domain radio resource configuration parameter includes:
indicating the parameters of a time domain resource period, a wireless frame offset and a subframe position discovered by equipment, and determining the time domain resource for equipment discovery by the user equipment according to the parameters; or,
indicating the parameters of a time domain resource period and subframe offset discovered by equipment, and determining the time domain resource used for equipment discovery by the user equipment according to the parameters; or,
indicating the parameters of the time domain resource period and the subframe position discovered by the equipment, and determining the time domain resource for equipment discovery by the user equipment according to the parameters; or,
and the user equipment determines time domain resources for equipment discovery according to the parameters.
Preferably, in the above method, the frequency domain radio resource configuration parameter is represented by one of the following manners:
a predefined frequency domain resource configuration index; or,
resource allocation parameters based on a frequency domain resource block allocation mode defined by a Long Term Evolution (LTE) system; or,
a parameter used to indicate the start of a frequency domain resource.
Preferably, in the above method, the determining, by the ue, the device discovery resource for device discovery signal transmission according to the first configuration signaling includes:
the user equipment determines a discovery signal sending time slot in the equipment discovery resource according to a preset rule, and sends an equipment discovery signal in the sending time slot, wherein the preset rule comprises:
the user equipment randomly selects a time slot in the time domain resource to send an equipment discovery signal; or,
the user equipment determines a time slot in the time domain resource period, and sends an equipment discovery signal in the time slot, wherein the determination mode is random selection; or,
the user equipment determines a sending period of a discovery signal and sends the equipment discovery signal according to the sending period, wherein the sending period is integral multiple of the time domain common resource period; or,
and the user equipment calculates the sending time slot of the discovery signal according to the user equipment identification and an agreed formula, and sends the discovery signal in the sending time slot.
Preferably, in the method, the frequency domain resource where the ue sends the device discovery signal is a frequency band indicated by a frequency domain radio resource configuration parameter in the first configuration signaling.
Preferably, in the above method, the determining, by the ue, the device discovery resource for device discovery signal transmission according to the first configuration signaling includes:
and the user equipment detects a device discovery signal in the device discovery resource, and discovers target user equipment through the detection.
Preferably, the method further comprises:
the user equipment receives a second configuration signaling of equipment discovery sent by the network side equipment, determines a user equipment dedicated resource for equipment discovery signal transmission according to the first configuration signaling and the second configuration signaling, and sends an equipment discovery signal in the dedicated resource;
wherein, the second configuration signaling at least comprises one or more of the following parameters:
time domain radio resource configuration parameters indicating user equipment-specific device discovery frames and/or subframes;
a frequency domain radio resource configuration parameter for indicating a user equipment-specific device discovery band location;
a sequence configuration parameter for indicating a user equipment-specific device discovery signal sequence;
a power control parameter for indicating a user equipment specific device discovery signal transmission power.
Preferably, in the above method, the time domain radio resource configuration parameter in the second configuration signaling at least includes one or more of the following parameters:
parameters for indicating a UE-specific device discovery resource period, a radio frame offset, and a subframe location;
parameters indicating a user equipment-specific device discovery subframe period, subframe offset.
Preferably, in the above method:
the second configuration signaling is a high-level signaling and is carried through a dedicated RRC signaling; or,
the second configuration signaling is physical layer signaling and is carried by downlink control information or a physical downlink shared channel.
Preferably, the method further comprises:
the user equipment receives a second configuration signaling of equipment discovery sent by the network side equipment, determines a sending or detecting time slot of the equipment discovery signal according to the first configuration signaling and the second configuration signaling, and sends or detects the equipment discovery signal in the time slot;
wherein, the second configuration signaling is used for triggering the user equipment to send or detect a device discovery signal, and at least includes one or several of the following parameters:
a trigger parameter for instructing the user equipment to perform device discovery signal transmission or detection;
a parameter indicating a device discovery signal transmission period;
an indication parameter for indicating a number or duration of device discovery signal transmissions;
a device discovery signal index parameter for indicating a sequence of device discovery signals;
a power control parameter for indicating a user equipment specific device discovery signal transmission power.
Preferably, in the above method, the second configuration signaling is physical layer signaling and is carried by downlink control information or a physical downlink shared channel.
Preferably, in the above method:
the wireless resources are allocated in an uplink frequency band of a Frequency Division Duplex (FDD) system; or,
the wireless resources are distributed in an uplink subframe of a Time Division Duplex (TDD) system; or,
the radio resources are configured in a dedicated frequency band, which means that the frequency band is dedicated for device-to-device communication.
The invention also discloses a device discovery method for device-to-device communication, which comprises the following steps:
a network side device sends a device discovery first configuration signaling to a user device, wherein the first configuration signaling configures a device discovery resource for device discovery signal transmission, and the user device performs device discovery through the device discovery resource;
wherein, the first configuration signaling at least comprises one or more of the following parameters:
time domain radio resource configuration parameters for indicating device discovery frames and/or subframes;
a frequency domain radio resource configuration parameter for indicating a device discovery band location;
a sequence configuration parameter for indicating a device discovery signal sequence.
Preferably, the method further comprises:
the network side sends a second configuration signaling of the user equipment dedicated resource for determining equipment discovery signal transmission to the user equipment;
wherein, the second configuration signaling at least comprises one or more of the following parameters:
time domain radio resource configuration parameters indicating user equipment-specific device discovery frames and/or subframes;
a frequency domain radio resource configuration parameter for indicating a user equipment-specific device discovery band location;
a sequence configuration parameter for indicating a user equipment-specific device discovery signal sequence;
a power control parameter for indicating a user equipment specific device discovery signal transmission power.
Preferably, the method further comprises:
the network side sends a second configuration signaling for triggering the user equipment to send or detect a device discovery signal to the user equipment;
wherein, the second configuration signaling at least comprises one or more of the following parameters:
a trigger indication parameter for indicating the user equipment to perform device discovery signal transmission or detection;
a parameter indicating a device discovery signal transmission period;
an indication parameter for indicating a number of times or duration that the user equipment transmits a device discovery signal;
a device discovery signal index parameter for indicating the device discovery signal sequence;
a power control parameter for indicating a user equipment specific device discovery signal transmission power.
The invention also discloses a user equipment, comprising:
the first communication module receives a device discovery first configuration signaling sent by a network side device, wherein the first configuration signaling at least comprises one or more of the following parameters:
time domain radio resource configuration parameters for indicating device discovery frames and/or subframes;
a frequency domain radio resource configuration parameter for indicating a device discovery band location;
a sequence configuration parameter for indicating a device discovery signal sequence;
a resource determining module, configured to determine a device discovery resource for device discovery signal transmission according to the first configuration signaling;
a second communication module to transmit a device discovery signal or detect a device discovery signal through the device discovery resource, wherein the device discovery signal is used for device discovery for device-to-device communication.
Preferably, in the above user equipment, the determining, by the resource determining module, the device discovery resource for device discovery signal transmission according to the first configuration signaling includes:
the resource determining module determines a discovery signal transmission time slot in the device discovery resource according to a preset rule, wherein the preset rule includes:
randomly selecting a time slot for device discovery signal transmission in the time domain resource; or,
determining a time slot for sending a device discovery signal in the time domain resource period, wherein the determined mode is random selection; or,
determining a transmission period of a discovery signal, and determining a time slot for transmitting a device discovery signal in the transmission period, wherein the transmission period is an integral multiple of the time domain common resource period; or,
and calculating the sending time slot of the discovery signal according to the user equipment identification and an appointed formula.
Preferably, in the user equipment, the frequency domain resource for sending the device discovery signal is a frequency band indicated by the frequency domain radio resource configuration parameter in the first configuration signaling.
Preferably, in the user equipment, the second communication module detects a device discovery signal in the device discovery resource, and discovers the target user equipment through the detection.
Preferably, in the user equipment, the first communication module is further configured to receive a second configuration signaling for device discovery sent by the network side device, where the second configuration signaling at least includes one or more of the following parameters:
time domain radio resource configuration parameters indicating user equipment-specific device discovery frames and/or subframes;
a frequency domain radio resource configuration parameter for indicating a user equipment-specific device discovery band location;
a sequence configuration parameter for indicating a user equipment-specific device discovery signal sequence;
a power control parameter for indicating a user equipment-specific device discovery signal transmission power;
the resource determining module determines a user equipment dedicated resource for device discovery signal transmission according to the first configuration signaling and the second configuration signaling;
the second communication module transmits a device discovery signal in the dedicated resource.
Preferably, in the user equipment:
the first communication module is further configured to receive a device discovery second configuration signaling sent by the network side device and used for triggering user equipment to send or detect a device discovery signal, where the second configuration signaling at least includes one or more of the following parameters:
a trigger parameter for instructing the user equipment to perform device discovery signal transmission or detection;
a parameter indicating a device discovery signal transmission period;
an indication parameter for indicating a number or duration of device discovery signal transmissions;
a device discovery signal index parameter for indicating a sequence of device discovery signals;
a power control parameter for indicating a user equipment-specific device discovery signal transmission power;
the resource determining module determines a sending or detecting time slot of a device discovery signal according to the first configuration signaling and the second configuration signaling;
the second communication module transmits or detects the device discovery signal in the time slot.
The invention also discloses a network side device, comprising:
the resource configuration module is used for configuring the device discovery resources and generating a first configuration signaling for device discovery, wherein the first configuration signaling at least comprises one or more of the following parameters:
time domain radio resource configuration parameters for indicating device discovery frames and/or subframes;
a frequency domain radio resource configuration parameter for indicating a device discovery band location;
a sequence configuration parameter for indicating a device discovery signal sequence;
a communication module to transmit the device discovery first configuration signaling in a broadcast form.
Preferably, in the network side device, the time domain radio resource configuration parameter includes:
indicating the parameters of a time domain resource period, a wireless frame offset and a subframe position discovered by equipment, and determining the time domain resource for equipment discovery by the user equipment according to the parameters; or,
indicating the parameters of a time domain resource period and subframe offset discovered by equipment, and determining the time domain resource used for equipment discovery by the user equipment according to the parameters; or,
indicating the parameters of the time domain resource period and the subframe position discovered by the equipment, and determining the time domain resource for equipment discovery by the user equipment according to the parameters; or,
and the user equipment determines time domain resources for equipment discovery according to the parameters.
Preferably, in the above network side device, the frequency domain radio resource configuration parameter is represented by one of the following modes:
a predefined frequency domain resource configuration index; or,
resource allocation parameters based on a frequency domain resource block allocation mode defined by a Long Term Evolution (LTE) system; or,
a frequency domain resource start parameter.
Preferably, in the network side device:
the resource configuration module is configured to configure a user equipment dedicated resource for device discovery and generate a second configuration signaling after the communication module sends the first configuration signaling;
the communication module sends the second configuration signaling to the user equipment, wherein the second configuration signaling at least comprises one or more of the following parameters:
time domain radio resource configuration parameters indicating user equipment-specific device discovery frames and/or subframes;
a frequency domain radio resource configuration parameter for indicating a user equipment-specific device discovery band location;
a sequence configuration parameter for indicating a user equipment-specific device discovery signal sequence;
a power control parameter for indicating a user equipment specific device discovery signal transmission power.
Preferably, in the network side device, the time domain radio resource configuration parameter in the second configuration signaling at least includes one or more of the following parameters:
parameters for indicating a UE-specific device discovery resource period, a radio frame offset, and a subframe location;
parameters indicating a user equipment-specific device discovery subframe period, subframe offset.
Preferably, in the network-side device described above,
the second configuration signaling is a high-level signaling and is carried through a dedicated RRC signaling; or,
the second configuration signaling is physical layer signaling and is carried by downlink control information or a physical downlink shared channel.
Preferably, in the above network side device, after the communication module sends the first configuration signaling, the resource configuration module further generates a second configuration signaling that triggers the user equipment to send or detect a device discovery signal, where the second configuration signaling at least includes one or more of the following parameters:
a trigger indication parameter for indicating the user equipment to perform device discovery signal transmission or detection;
a parameter indicating a device discovery signal transmission period;
an indication parameter for indicating a number of times or duration that the user equipment transmits a device discovery signal;
a device discovery signal index parameter for indicating the device discovery signal sequence;
a power control parameter for indicating a user equipment-specific device discovery signal transmission power;
the communication module sends the second configuration signaling to the user equipment.
Preferably, in the network side device, the second configuration signaling is physical layer signaling and is carried by downlink control information or a physical downlink shared channel.
Preferably, in the network-side device described above,
the wireless resources are allocated in an uplink frequency band of a Frequency Division Duplex (FDD) system; or,
the wireless resources are distributed in an uplink subframe of a Time Division Duplex (TDD) system; or,
the radio resources are configured in a dedicated frequency band, which means that the frequency band is dedicated for device-to-device communication.
The technical scheme of the application solves the problem of device discovery of device-to-device communication in a cellular communication system, avoids interference between device discovery of device-to-device communication and cellular communication, ensures the efficiency of device discovery, and is beneficial to improving the universality of device-to-device communication application.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be further described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments of the present application may be arbitrarily combined with each other without conflict.
The techniques described herein are applicable to a cellular wireless communication system or network. A common cellular wireless communication system may be based on CDMA (Code Division multiple Access) technology, FDMA (Frequency Division multiple Access) technology, OFDMA (Orthogonal-FDMA) technology, SC-FDMA (Single Carrier-FDMA), Single Carrier-Frequency Division multiple Access) technology, and the like. For example, the downlink (or referred to as the forward link) of a 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution)/LTE-a (LTE-Advanced) cellular communication system is based on OFDMA technology and the uplink (or referred to as the reverse link) is based on SC-FDMA multiple access technology. It is possible in the future to support hybrid multiple access techniques on one link.
In an OFDMA/SC-FDMA system, the wireless communication resources are in the form of two dimensions, time-frequency. For example, for the LTE/LTE-a system, the communication resources of the uplink and downlink are divided in units of radio frames (radio frames) in the time direction, each radio frame (radio frame) has a length of 10ms, and includes 10 subframes (sub-frames) with a length of 1ms, and each subframe includes two slots (slots) with a length of 0.5ms, as shown in fig. 1. And each slot may include 6 or 7 OFDM or SC-FDM symbols depending on a configuration of a Cyclic Prefix (CP).
In the frequency direction, resources are divided in units of subcarriers (subcarriers), and specifically, in communication, the minimum unit of frequency domain Resource allocation is RB (Resource Block) and corresponds to one PRB (Physical RB) of a Physical Resource. One PRB includes 12 sub-carriers in the frequency domain, corresponding to one slot (slot) in the time domain. The Resource corresponding to one subcarrier on each OFDM/SC-FDM symbol is called a Resource Element (RE). As shown in fig. 2.
In LTE/LTE-a cellular communication, a user equipment UE discovers an LTE network by detecting a Synchronization Signal (SS). The synchronization signals include Primary Synchronization Signals (PSS) and Secondary Synchronization Signals (SSs). By detecting the synchronization signal, the UE acquires downlink frequency and time synchronization with the base station. Moreover, since the synchronization signal carries the physical cell identifier, detecting the synchronization signal also means that the UE finds the LTE/LTE-a cell.
In the uplink, when the UE has uplink data transmission, it needs to initiate Random Access (RA) for uplink synchronization and establish RRC (Radio Resource Control), that is, enter an RRC Connected (Connected) state from an RRC Idle (Idle) state. When the random access is performed, the UE needs to send a random access preamble (preamble), and the network side detects the random access preamble in a specific time-frequency resource to identify the UE and synchronize the uplink.
Fig. 3 is a schematic diagram of a network deployment of a cellular wireless communication system. The illustration may be a 3gpp LTE/LTE-a system, or other cellular wireless communication technology. In an access network of a cellular wireless communication system, a network device generally includes a certain number of base stations (referred to as Node bs, evolved Node bs, enbs, or enhanced Node bs, enbs), and other network entities (network entities). Or, in summary, it may also be referred to as an Evolved Universal terrestrial radio Access Network (E-UTRAN), which is referred to as a Network side E-UTRAN. The base station herein also includes a Low Power Node (LPN) in the network, such as a femtocell or a Home base station (pico, Relay, femto, HeNB, or Home eNB). For simplicity of description, only 3 base stations are shown in fig. 3. A base station provides a certain coverage area for radio signals, and terminals (or User equipments, UEs, or devices) within the coverage area can communicate with the base station wirelessly. The wireless signal coverage area of a base station may be divided into one or more cell cells or sector sectors based on some criteria, for example, three cells, and the wireless communication of each cell may be processed by a separate subsystem, for example, a separate rf unit.
When device discovery for device-to-device communication is performed in a cellular communication system, since device discovery uses wireless resources of a cellular network, the device discovery process may require network-side assistance, device discovery is managed by the network assistance, interference of the device discovery on cellular communication is avoided, and efficiency of device discovery is improved by the network assistance. The network entity managing the radio resources is typically a base station, e.g. a radio resource may be allocated by the base station for device discovery, in which a UE performing device discovery of device-to-device communication transmits or detects a device discovery signal. Alternatively, the allocation of the radio resources may be performed by the base station according to an instruction from an upper network entity.
Specifically, the device discovery method based on the above consideration includes:
user equipment receives a first configuration signaling of equipment discovery sent by a network side; and the user equipment determines equipment discovery resources used for equipment discovery signal transmission according to the first configuration signaling, and performs equipment discovery through the equipment discovery resources. Wherein the first configuration signaling is sent in a broadcast form and includes at least one of: time domain radio resource configuration parameters for indicating device discovery frames and/or subframes; a frequency domain radio resource configuration parameter for indicating a device discovery band location; a sequence configuration parameter for indicating a device discovery signal sequence.
The following describes the implementation process of the above method in detail with reference to practical applications.
Example 1
The first configuration signaling may include a time domain radio resource configuration parameter for indicating a device discovery frame and/or subframe, and the time domain radio resource configuration parameter is used for configuring the device discovery time domain resource.
The radio frames for device discovery may be allocated by a time domain resource period, a radio frame offset. For example, an allocation Period (Period) of a device discovery radio Frame and a radio Frame allocation Offset (Offset) may be defined, and when a System Frame Number (SFN) of the radio Frame satisfies SFN modperiodic ═ Offset, the radio Frame is indicated as a radio Frame used for device discovery, and mod indicates a modulo operation. For example, the allocation period may be configurable, such as 1, 2, 4, 8, 16, 32, 64, etc., the allocation offset may be configurable, such as 0/1/2/3/4/5/6/7, etc.; alternatively, the allocation period may be agreed, such as 16, or 32, the allocation offset may be configurable, such as 0-16, or 0-32, etc. It should be noted that the numbers are only examples and should not be construed as limiting the invention. The numerical value may take any integer value within the system frame number range.
By configuring the device discovery radio frame with the aforementioned period and offset, the device discovery subframe may be reconfigured in the radio frame, for example, a subframe configured as a device discovery resource in the radio frame may be represented in the form of a bitmap, for example, a bitmap which may be m bits represents a device discovery subframe configured in one radio frame, and m is a maximum number of subframes configurable as a device discovery subframe in one radio frame, such as 5 or 6 or 10; or, the device discovery subframe may also be configured with a plurality of radio frames as a basic unit, for example, 2 or 4 or 8 or 16 or 32 radio frames as a basic time unit, where the size of the bitmap is 2m, 4m, 8m, 16m, and 32m bits, respectively, and m is as defined above. It should also be noted that 2/4/8/16/32 is exemplary and not limiting. In conclusion, the configuration of the device discovery time domain common resource can be realized.
One example is shown in figure 4. The time domain resource period configured by the first configuration signaling is 4, which means that the time domain resource period is 4 wireless frames; the configured radio frame offset is 1, indicating that a radio frame satisfying SFN mod4 ═ 1 is configured as a device discovery radio frame; the bitmap is 0000001000, indicating that subframe number 6 within the device discovery radio frame is configured as a device discovery subframe.
In another example, the time domain resource period is the same as the offset above, but the bitmap is 100000, indicating that the subframe numbered 1 within the device discovery radio frame that can be configured as a device discovery subframe is configured as a device discovery subframe. For example, in the TDD system, the subframe configurable as the device discovery subframe is an uplink subframe, and the maximum set of uplink subframe numbers in the TDD system is 2/3/4/7/8/9 (subframe numbers 0-9), and the bitmap described above indicates that the subframe number 2 is configured as the device discovery subframe.
Or, the time domain resource is configured by indicating a period and a subframe offset. For example, an allocation Period (Period) of the device discovery resource may be defined, and the allocation Period may be used to indicate a repetition interval or time of the device discovery resource, for example, the allocation Period may be in units of radio frames, and may be configured to be 1, 2, 4, 8, 16, 32, etc., indicating that the device discovery resource is repeated once by 1 or 2 or 4. The allocation period may also be configured in units of other time units, such as n radio frames (n is an integer greater than or equal to 1, for example, n ═ 4), may be configured to be 1, 2, 3, 4, and so on, and respectively indicate that the repetition period of the device discovery resource is n, 2n, 3n, 4n.. radio frames; or may also be configured in units of subframes, for example, may be configured as 5, 10, 20, 40, 80, 160, and so on, which respectively indicate that the repetition period of the device discovery resource is 5, 10, 20, 40, 80, 160 subframes.
The subframe Offset (Offset) parameter included in the time domain resource configuration is used to indicate a specific subframe position within the time domain resource allocation period. For example, the subframe offset may be configured as 0/1/2/3/4/. to indicate that the 1/2/3/4/5/. to.. subframes are configured as device discovery resources within the time domain resource allocation period, respectively. It should be noted that the numbers are only examples and should not be construed as limiting the invention.
For example, a device discovery resource period is configured in units of subframes, and an example of determining a specific subframe position by subframe offset is shown in fig. 5. In this configuration, when the Subframe Number (SN) satisfies (SFN × 10+ SN) mod Period ═ Offset, it indicates that the subframe is configured as a device discovery subframe. In fig. 5, the Period of the device discovery resource configured by the first configuration signaling is 320 milliseconds, that is, 320 subframes; the subframe Offset, is 83, based on which it may be determined that the device discovery subframe is as shown in the blue subframe in fig. 5.
Alternatively, the subframe offset may also indicate that k consecutive subframes beginning with the 1/2/3/4/5/. ang. subframe within the time domain resource allocation period are configured as device discovery resources, where k is an integer greater than or equal to 1, and may be configured by signaling or agreed in the system. For the example of fig. 5, if the convention or configuration k is 2, then the device discovery subframe of the first configuration signaling configuration is as shown in the blue subframe in fig. 6.
Alternatively, the time domain resource may be configured by indicating the period and the subframe position. The description of the period is the same as that described above and is not repeated.
The subframe location parameter included in the time domain resource configuration is used to indicate a specific allocated subframe in the time domain resource allocation period. For example, the subframe position may be configured in a bitmap manner, and whether the bitmap has a 1 position indicates whether the subframe corresponding to the bit is configured as the device discovery subframe.
Or, the time domain resource is determined by indicating the subframe combination. For example, subframes belonging to one uplink Hybrid automatic Repeat Request (HARQ) Process (Process) may be agreed as one combination, so that there are 8 combinations in total, and an 8-bit bitmap is used to indicate whether or not the subframe in the corresponding combination is configured as a device discovery subframe. For example, the 1 st bit in the bitmap indicates that the subframe with the subframe number SN satisfying (SFN × 10+ SN) mod8 ═ 0 is configured as the device discovery subframe (SN ranges from 0 to 9), the 2 nd bit in the bitmap indicates that the subframe with the subframe number SN satisfying (SFN × 10+ SN) mod8 ═ 1 is configured as the device discovery subframe, and so on.
Example 2
The first configuration signaling may further include a frequency domain radio resource configuration parameter for indicating a device discovery band location, where the frequency domain radio resource configuration parameter is used to allocate device discovery frequency domain resources.
The frequency domain resources may be allocated by a frequency domain resource block allocation manner in the LTE system (that is, the frequency domain wireless configuration parameter in the first configuration signaling is a resource allocation parameter based on the frequency domain resource block allocation manner defined by the LTE system). For example, the frequency domain Resource allocation may be performed by Resource allocation type 0(Resource allocation type0, RA type0), Resource allocation type 1(RA type1), or Resource allocation type 2(RA type2), which will not be described in detail.
Alternatively, the frequency domain resources may be allocated in a bitmap (bitmap) manner (that is, the frequency domain radio configuration parameter in the first configuration signaling is a predefined frequency domain resource configuration index). For example, if the device discovery signal occupies k resource blocks in the frequency domain, the length of the bitmap is n/k rounded down (i.e., the bitmap is n/k rounded down)) And n is the system bandwidth of the carrier where the frequency domain resource is located or the maximum bandwidth of one carrier supported by the system, and the unit is a resource block. Whether a bit in the bitmap is set to 1 indicates whether the frequency band represented by the bit is configured as a device discovery resource. Alternatively, the bitmap may be n in length, with each bit representing the bitWhether the resource block to which the bit corresponds is configured as a device discovery resource.
Or, the frequency domain resources are allocated by using the frequency offset parameter, that is, the frequency domain wireless configuration parameter in the first configuration signaling is a parameter indicating the start of the frequency domain resources, and at this time, the user can determine the frequency domain resources for device discovery according to the parameter of the start of the frequency domain resources and the pre-agreed frequency domain resource bandwidth. For example, if the device discovery signal occupies k resource blocks in the frequency domain, the value of the frequency offset parameter is 0 to n/k rounded down, and the meaning of n is the same as the foregoing. Taking 0 indicates that k resource blocks with resource block numbers starting from 0 are configured as device discovery resources, taking 1 indicates that k resource blocks with resource block numbers starting from k +1 are configured as device discovery resources, taking 2 indicates that k resource blocks with resource block numbers starting from 2 × k +1 are configured as device discovery resources, and so on. Or, the value of the frequency offset parameter is 0 to n-k, taking 0 indicates that k resource blocks with resource block numbers starting from 0 are configured as the device discovery resource, taking 1 indicates that k resource blocks with resource block numbers starting from 1 are configured as the device discovery resource, taking 2 indicates that k resource blocks with resource block numbers starting from 2 are configured as the device discovery resource, and so on.
Example 3
The network device allocates the device discovery common resource according to the configuration mode, generates a first configuration signaling according to the device discovery common resource, and sends the first configuration signaling to the user equipment.
The first configuration signaling may be transmitted in the form of a broadcast. For example, the first configuration signaling may be sent through System Information (SI) and carried in a System Information Block (SI Block, SIB). The system information block may be a SIB of an existing system or a newly added SIB in the system, for example, a SIB newly added for D2D communication.
The user equipment supporting D2D device discovery or having D2D device discovery requirement receives the first configuration signaling transmitted by the broadcast.
When the user equipment has a requirement for sending the equipment discovery signal, the user equipment obtains an equipment discovery time domain resource set according to the received broadcast signaling, and determines a time domain resource, such as a subframe, for sending the equipment discovery signal in the resource set according to a preset rule.
The preset rule may be a manner of randomly selecting the time domain discovery resource. For example, in one period of the device discovery resource, the UE randomly selects the time domain resource in the time domain resource set, for example, selects one subframe to transmit the device discovery signal, that is, the UE transmits the device discovery signal with the period of the device discovery resource as a period. Or, the UE determines a transmission period of the device discovery signal, where the period is a multiple of the device discovery resource period, and in the device discovery signal transmission period, the UE randomly selects a time domain resource in the time domain resource set, for example, selects a subframe to transmit the device discovery signal, that is, the UE transmits the device discovery signal with a specific multiple of the device discovery resource period as a period.
The preset rule may be that the UE calculates the available time domain discovery resources according to the device identity (UE _ ID). For example, assuming that the period of sending the discovery signal by the UE is the same as the period of discovering the time domain resource by the device, that is, the discovery signal is sent once in each time domain resource period, and the user equipment calculates the time domain resource location of sending the discovery signal according to the device identifier. Assuming that N time domain resources or subframes are allocated in one time domain resource period for discovery signal transmission, the time domain subframe position of the UE sending the device discovery signal can be determined by using the UE _ ID mod N.
Alternatively, the period of the UE sending the discovery signal may be a multiple of the period of the device discovery time domain resource, for example, i represents the multiple, i may be an integer greater than or equal to 1, and the UE _ ID mod (i × N) may be used to determine the time domain subframe position of the UE sending the device discovery signal.
The device identity (UE _ ID) may be an RNTI (Radio network temporary identity) of the user equipment or a partial bit in the RNTI, or an IMSI (International Mobile Subscriber identity) or a partial bit in the IMSI. The part of the bits may be, for example, a part of the binary identification. The device identifier may also be other identifiers, which is not described in detail.
Example 4
In this embodiment, the allocated device discovery resource set is indicated to the user equipment through the first configuration signaling, and the user equipment is triggered or authorized to perform the transmission of the device discovery signal through the second configuration signaling.
Specifically, in this embodiment, the device discovery process of device-to-device communication is as follows:
the user equipment receives a first configuration signaling sent by the network equipment through the broadcast message, and the user equipment determines the equipment discovery time domain resource set according to the first configuration signaling, wherein the specific description and the sending mode of the first configuration signaling can refer to embodiment 1; when the network device authorizes the user device to send the device discovery signal, the network device sends a second configuration signaling to the user device, and the user device is triggered or authorized to send the device discovery signal through the second configuration signaling.
In one embodiment, the first configuration signaling may be used for configuring the device discovery common parameter, such as configuring a device discovery time domain common resource set, a frequency domain resource set; the second configuration signaling may be used for configuration of device discovery specific parameters, e.g. device discovery time domain specific resources of the configurable user equipment. When the time domain resource, such as the subframe, meets the condition that the subframe is the subframe in the device discovery time domain resource set configured by the first configuration signaling and the subframe is the user equipment special device discovery subframe configured by the second configuration signaling, the user equipment sends a device discovery signal in the subframe.
One specific example is shown in fig. 7. In the figure, the device discovery time domain resource set configured by the first configuration signaling is a subframe represented by blue, the ue dedicated device discovery resource configured by the second configuration signaling is a subframe represented by red, and the two subframes coincide with each other, that is, the subframe represented by red is a subframe in which the ue transmits a device discovery signal.
The second configuration signaling can configure the time domain radio frame position of the UE-specific device discovery resource by configuring the radio frame period and the radio frame offset, and set the device discovery subframe position in the radio frame through a bitmap. For example, in the ue-specific device discovery resource configuration shown in fig. 7, the radio frame period indicated by the second configuration signaling is 2, the radio frame offset is 1, and the bitmap is 0001000000.
Alternatively, the second configuration signaling may configure the UE specific device discovery subframe by configuring a subframe period, a subframe offset. For example, the ue-specific discovery resource configuration shown in fig. 7, the subframe period indicated by the second configuration signaling is 20, and the subframe offset is 13.
Alternatively, the second configuration signaling may configure the UE-specific device discovery subframe by configuring a transmission period and a subframe offset of the device discovery signal. For example, the configured period of the device discovery time domain common resource is represented by a radio frame as Pr, and then the transmission period Pt configured by the second configuration signaling may be an integer greater than or equal to 1, which represents that the period of the ue sending the device discovery signal is represented by a radio frame as Pt × Pr; the subframe offset is used to indicate the location of the dedicated device discovery subframe configured for the user equipment within the transmission period. For example, in the example shown in fig. 7, Pr is 1, Pt is 2, that is, the transmission period of the device discovery signal configured for the ue by the second configuration signaling is 2 radio frames, and the subframe offset is 1, which indicates that the 2 nd device discovery subframe is configured as a device discovery dedicated subframe of the ue in the transmission period.
It should be noted that each parameter configured in the second configuration signaling may be represented by an independent parameter in the second configuration signaling, or each parameter may be jointly encoded and represented by an independent parameter obtained by joint encoding.
The second configuration signaling described in this example may be higher layer signaling, for example, sent to the user through RRC signaling. Or may be physical layer signaling, for example, the signaling is sent through a physical downlink shared channel PDSCH indicated by a physical downlink control channel PDCCH; or sending through PDCCH, for example, second configuration signaling may be set in existing downlink control information DCI or DCI for D2D communication scheduling, or reuse some DCI formats in the system to perform transmission of the second configuration signaling, for example, redefine DCI format 0 or format 1A or format 3 or other existing formats, and use the DCI format to perform bearer of the second configuration signaling.
After receiving the first configuration signaling and the second configuration signaling, the user equipment determines an equipment discovery subframe according to the configuration signaling, and sends or detects an equipment discovery signal in the equipment discovery subframe.
When the second configuration signaling is sent in a physical layer signaling manner, the second configuration signaling may also be used to trigger the user equipment to send the device discovery signal.
For example, a trigger indication parameter is included in the second configuration signaling, and the trigger parameter indicates whether the transmission of the device discovery signal is triggered. It may be agreed that, after receiving the second configuration signaling in subframe m, the ue transmits the device discovery signal in the first device discovery subframe that satisfies that the interval with the second configuration signaling transmission subframe is greater than or equal to k, where k is an agreed integer, for example, k may be 4, or k may be 6, and so on.
One specific example is shown in fig. 8. In the figure, the device discovery time domain resource set configured by the first configuration signaling is shown as a blue subframe in the figure, and the second configuration signaling is sent in a subframe 9 (subframe number 0-9) of a radio frame 4n + 1. And after receiving the second configuration signaling in the subframe 9 of the radio frame 4n +1, the user equipment sends a device discovery signal in the first device discovery subframe which has the interval greater than or equal to k with the subframe 9 of the radio frame 4n + 1. For example, k is 4, the ue transmits a device discovery signal in subframe 3 of radio frame 4n + 2; e.g., k is 6, the ue transmits a device discovery signal in subframe 3 of radio frame 4(n + 1).
After the user equipment receives the second configuration signaling, the number of times of sending the device discovery signal may be only one time, or multiple times. The multiple transmissions may be determined by a convention form, for example, after the convention user equipment receives the second configuration signaling, the transmission is continued for i times in the next available device discovery subframe satisfying the interval requirement, where i is an integer greater than or equal to 1. The number of transmissions may also be configured, for example, the second configuration signaling also includes a parameter for indicating the number of continuous transmissions of the device discovery signal, and the user equipment determines the number of continuous transmissions of the device discovery signal according to the indication of the parameter.
When the device discovery signal is transmitted multiple times, the device discovery signal may be transmitted in each device discovery subframe that meets the time interval requirement, or may be transmitted in a periodic form, for example, a period in which the user equipment is instructed to transmit the device discovery signal in the second configuration signaling may be represented by a multiple of a period of the device discovery time domain resource, for example, 1/2/3/4 may be configured, and the period in which the user equipment transmits the device discovery signal is 1/2/3/4. For the example in fig. 8, the device discovery time domain resource period is 20ms, and then configured as 1/2/3/4.
The second configuration signaling may also include a power control parameter for indicating the transmission power of the device discovery signal dedicated to the user equipment, and the user equipment sets the transmission power of the device discovery signal according to the parameter.
Example 5
The present embodiment provides a device discovery method for device-to-device communication, which mainly includes the following operations:
the network side equipment sends a first configuration signaling for equipment discovery to the user equipment, the first configuration signaling configures equipment discovery resources used for equipment discovery signal transmission, and the user equipment discovers the equipment through the equipment discovery resources;
the first configuration signaling at least comprises one or more of the following parameters:
time domain radio resource configuration parameters for indicating device discovery frames and/or subframes;
a frequency domain radio resource configuration parameter for indicating a device discovery band location;
a sequence configuration parameter for indicating a device discovery signal sequence.
Specifically, the description of each parameter included in the first configuration signaling may refer to the corresponding content in the foregoing embodiments 1 and 2, and is not repeated herein.
Some further schemes provide that, on the basis of the foregoing method, the network side may further send, to the user equipment, a second configuration signaling for determining a user equipment-specific resource for device discovery signal transmission, where the second configuration signaling includes at least one or more of the following parameters:
time domain radio resource configuration parameters indicating user equipment-specific device discovery frames and/or subframes;
a frequency domain radio resource configuration parameter for indicating a user equipment-specific device discovery band location;
a sequence configuration parameter for indicating a user equipment-specific device discovery signal sequence;
a power control parameter for indicating a user equipment specific device discovery signal transmission power.
Another scheme provides that, on the basis of the foregoing method, the network side may also send, to the user equipment, a second configuration signaling for triggering the user equipment to send or detect a device discovery signal, where the second configuration signaling at least includes one or more of the following parameters:
a trigger indication parameter for indicating the user equipment to perform device discovery signal transmission or detection;
an indication parameter for indicating a number of times or duration that the user equipment transmits a device discovery signal;
a device discovery signal index parameter for indicating the device discovery signal sequence;
a power control parameter for indicating a user equipment specific device discovery signal transmission power.
It should be noted that the second configuration signaling involved in the above two schemes may be a higher layer signaling, which is carried by a dedicated RRC signaling. Or physical layer signaling, which is carried by downlink control information or a physical downlink shared channel.
Specifically, the time domain radio resource configuration parameter in the second configuration signaling at least includes one or more of the following parameters:
parameters for indicating a UE-specific device discovery resource period, a radio frame offset, and a subframe location;
parameters indicating a user equipment-specific device discovery subframe period, subframe offset.
Example 6
This embodiment provides a user equipment, which can implement the device discovery methods of embodiments 1 and 2, and the structure of the user equipment is shown in fig. 9, and includes a first communication module, a resource determination module, and a second communication module.
The first communication module is used for communicating with the network equipment and receiving equipment discovery first configuration signaling sent by the network side equipment, wherein the first configuration signaling at least comprises one or more of the following parameters:
time domain radio resource configuration parameters for indicating device discovery frames and/or subframes;
a frequency domain radio resource configuration parameter for indicating a device discovery band location;
a sequence configuration parameter for indicating a device discovery signal sequence.
A resource determining module, configured to determine a device discovery resource for device discovery signal transmission according to the first configuration signaling;
specifically, the determining, by the resource determining module, the device discovery resource for device discovery signal transmission according to the first configuration signaling includes:
the resource determining module determines a discovery signal transmission time slot in the device discovery resource according to a preset rule, wherein the preset rule includes:
randomly selecting a time slot for device discovery signal transmission in the time domain resource; or,
determining a time slot for sending a device discovery signal in the time domain resource period, wherein the determined mode is random selection; or,
determining a transmission period of a discovery signal, and determining a time slot for transmitting a device discovery signal in the transmission period, wherein the transmission period is an integral multiple of the time domain common resource period; or,
and calculating the sending time slot of the discovery signal according to the user equipment identification and an appointed formula.
And the second communication module is used for sending the device discovery signal or detecting the device discovery signal through the device discovery resource and carrying out device discovery of device-to-device communication according to the device discovery signal.
Specifically, the second communication module detects a device discovery signal in the device discovery resource, and discovers the target user device through the detection.
In some other schemes, a first communication module in the user equipment may further receive a device discovery second configuration signaling sent by the network side device, where the second configuration signaling at least includes one or more of the following parameters:
time domain radio resource configuration parameters indicating user equipment-specific device discovery frames and/or subframes;
a frequency domain radio resource configuration parameter for indicating a user equipment-specific device discovery band location;
a sequence configuration parameter for indicating a user equipment-specific device discovery signal sequence;
a power control parameter for indicating a user equipment specific device discovery signal transmission power.
At this time, the resource determining module determines the user equipment dedicated resource for device discovery signal transmission according to the first configuration signaling and the second configuration signaling;
the second communication module may be configured to transmit the device discovery signal in the determined dedicated resource.
Certainly, some other schemes provide that the first communication module in the user equipment may further receive a device discovery second configuration signaling sent by the network side device and used for triggering the user equipment to send or detect a device discovery signal, where the second configuration signaling at least includes one or more of the following parameters:
a trigger parameter for instructing the user equipment to perform device discovery signal transmission or detection;
an indication parameter for indicating a number or duration of device discovery signal transmissions;
a device discovery signal index parameter for indicating a sequence of device discovery signals;
a power control parameter for indicating a user equipment specific device discovery signal transmission power.
At this time, the resource determining module determines the sending or detecting time slot of the device discovery signal according to the first configuration signaling and the second configuration signaling;
the second communication module transmits or detects the device discovery signal in the determined time slot.
The specific forms of the first configuration signaling and the second configuration signaling related in the user equipment can be referred to corresponding contents in embodiments 1, 2, and 3, and are not described herein again.
Example 7
The present embodiment provides a network-side device, which can implement the device discovery methods in embodiments 1 to 3, and the structure of the network-side device is shown in fig. 10, and includes a resource configuration module and a communication module.
The resource configuration module is configured to configure the device discovery resource and generate a configuration signaling. The configuration signaling includes a first configuration signaling, and the specific form of the first configuration signaling may refer to the corresponding contents in embodiments 1 to 3, which are not described again.
The communication module is used for broadcasting the first configuration signaling configured by the resource configuration module to the user equipment;
some solutions further provide that, after the communication module sends the first configuration signaling, the resource configuration module in the network-side device further configures a second configuration signaling, where the second configuration signaling is used to allocate a device discovery resource dedicated to the user equipment in the resource configured by the first configuration signaling or is used to trigger the user equipment to send or detect a device discovery signal. At this time, the communication module sends the first configuration signaling and the second configuration signaling configured by the resource configuration module to the user equipment. For a specific form of the second configuration signaling, reference may be made to the corresponding contents in embodiments 1 to 3, which are not described again.
Example 8
The present embodiment provides a network-side device, whose structure is shown in fig. 11, and includes a resource configuration module, a trigger module, and a communication module.
A resource configuration module, configured to configure the device discovery resource and generate a first configuration signaling. And will not be described in detail.
And the triggering module is used for triggering the user equipment to send or detect the equipment discovery signal and generating a second configuration signaling.
The communication module is used for sending the first configuration signaling configured by the resource configuration module to the user equipment; and sending the second configuration signaling generated by the trigger module to the user equipment.
Wherein, the second configuration signaling at least comprises one or more of the following parameters:
a trigger indication parameter for indicating the user equipment to perform device discovery signal transmission or detection;
an indication parameter for indicating a number of times or duration that the user equipment transmits a device discovery signal;
a device discovery signal index parameter for indicating the device discovery signal sequence;
the communication module sends the second configuration signaling to the user equipment.
The second configuration signaling may be physical layer signaling, and is carried by downlink control information or a physical downlink shared channel.
The radio resource configured on the network side can be allocated in the uplink Frequency band of an FDD (Frequency Division duplex) system; or,
allocating in an uplink subframe of a Time Division Duplex (TDD) system; or,
configured in a dedicated frequency band, which refers to a frequency band dedicated to device-to-device communication.
It will be understood by those skilled in the art that all or part of the steps of the above methods may be implemented by instructing the relevant hardware through a program, and the program may be stored in a computer readable storage medium, such as a read-only memory, a magnetic or optical disk, and the like. Alternatively, all or part of the steps of the above embodiments may be implemented using one or more integrated circuits. Accordingly, each module/unit in the above embodiments may be implemented in the form of hardware, and may also be implemented in the form of a software functional module. The present application is not limited to any specific form of hardware or software combination.
The above description is only a preferred example of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.