CN105991247A

CN105991247A - Device-to-device sending method, receiving method, scheduling method and corresponding devices

Info

Publication number: CN105991247A
Application number: CN201510085284.3A
Authority: CN
Inventors: 吴栓栓; 戴博; 陈琳; 郁光辉; 贺海港; 黄莹
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2015-02-16
Filing date: 2015-02-16
Publication date: 2016-10-05
Also published as: WO2016131344A1

Abstract

The invention discloses a device-to-device (D2D) sending method, a device-to-device (D2D) receiving method, a device-to-device (D2D) scheduling method and corresponding devices. The objective of the invention is to improve the transmission efficiency of device-to-device (D2D) communication. The receiving method includes the following steps that: UE1 receives a D2D data packet sent by UE2; and the UE1 checks the D2D data packet and sends feedback information indicating a check result, wherein the feedback information is an ACK or an NACK, if the feedback information is an NACK, the retransmission of the D2D data packet is received. The sending method includes the following steps that: the UE2 transmits the D2D data packet to the UE1; and when the feedback information which is sent by the UE1 and received by the UE2 is an NACK, or the UE2 receives authorization information sent by network side equipment, the UE2 re-transmits the D2D data packet to the UE1. The scheduling method includes the following steps that: the network side equipment sends first authorization information to the UE2 and schedules the UE2 to send the D2D data packet to the UE1; and if the feedback information which is sent by the UE1 and received by the network side equipment is an NACK, the network side equipment sends second authorization information to the UE2 and schedules the UE2 to re-transmit the D2D data packet.

Description

Device-to-device transmitting, receiving and scheduling method and corresponding device

Technical Field

The invention relates to the field of wireless communication, in particular to a device-to-device transmitting, receiving and scheduling method and a corresponding device.

Background

With diversification of mobile communication services, for example, popularization of applications such as social networks, electronic payments, and the like in wireless communication systems, service transmission demands among close-range users are increasing. Therefore, a Device-to-Device (D2D) communication mode is receiving increasing attention. D2D is that Service data is directly transmitted to a target User Equipment (UE) through an air interface by a source User Equipment (UE) without being forwarded by a base station and a core network, which may also be referred to as Proximity Service (ProSe). For users of short-range communication, D2D not only saves wireless spectrum resources, but also reduces data transmission pressure of the core network.

The wireless communication generally includes communication modes such as broadcast (broadcast), multicast (groupcast), unicast (unicast), and the like. Broadcasting generally does not have a specific receiving end, for example, a device interested in a service transmitted by a transmitting end can receive the service; multicast is another one-to-many communication, and a terminal forming a communication group can receive a service sent by a sending end; unicast is to send the traffic to a specific receiver. LTE Rel-12 defines D2D broadcast communications at the physical layer. The broadcast communication of LTE Rel-12 includes two communication modes: mode 1 and mode 2. The former is broadcast communication based on eNB scheduling; the latter is autonomously selected by the UE for D2D transmissions in a D2D pool of communication resources.

D2D broadcast communication is characterized by the absence of HARQ ACK feedback, which is clearly not optimal for unicast communication.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a device-to-device transmitting, receiving, scheduling method and a corresponding apparatus, which implement HARQ feedback and improve the transmission efficiency of D2D communication.

In order to solve the above technical problem, the present invention provides a device-to-device D2D packet receiving method, including:

the method comprises the steps that a first User Equipment (UE) receives a D2D data packet sent by a second UE;

the first UE checks the received D2D data packet and sends feedback information indicating the checking result, wherein the feedback information is Acknowledgement (ACK) or non-acknowledgement (NACK), and if the feedback information is NACK, retransmission of the D2D data packet is received.

Further, a subframe for sending feedback information is a feedback subframe, and the first UE determines the position of the feedback subframe according to a preset rule or determines the position of the feedback subframe according to an indication in a control signaling.

Further, the determining, by the first UE, the position of the feedback subframe according to a preset rule includes: the preset rule is that a first preset interval is arranged between the feedback subframe and a subframe for receiving the D2D data packet, the first preset interval is a fixed time domain interval or a minimum time domain interval, and the first UE determines the position of the feedback subframe according to the position of the subframe for receiving the D2D data packet and the first preset interval.

Further, when the first UE determines the feedback subframe position according to the subframe position of the received D2D data packet and the first preset interval, the method further includes: when there is a D2D data reception need in the determined feedback subframe, the first UE relinquishing D2D data reception; when there is a D2D data transmission need in the determined feedback subframe and the target UE for the D2D data transmission is not the second UE, the first UE relinquishes D2D data transmission; when there is a requirement for transmitting D2D data in the determined feedback subframe and the target UE for transmitting the D2D data is the second UE, the first UE transmits the feedback information in the feedback subframe after multiplexing the feedback information with the D2D data.

Further, the determining, by the first UE, the position of the feedback subframe according to an indication in a control signaling includes: the indication in the control signaling comprises a parameter for indicating a position of a feedback subframe or a parameter for indicating a first feedback interval, wherein the first feedback interval is an interval between the feedback subframe and a subframe for receiving the D2D data packet, the first feedback interval is a fixed time domain interval or a minimum time domain interval, and the first UE determines the position of the feedback subframe according to the indication in the control signaling.

Further, the determining, by the first UE, the position of the feedback subframe according to the minimum time domain interval includes: determining a first available feedback subframe satisfying the minimum time domain interval as a feedback subframe for sending feedback information, wherein the first available feedback subframe refers to a subframe satisfying at least one of the following conditions: a subframe configured with feedback information transmission resources or indicated as a feedback information transmission subframe, a cellular communication data reception or transmission subframe other than the first UE, a D2D data reception or transmission subframe other than the first UE, a random access subframe other than the first UE.

Further, the first UE receiving the retransmission of the D2D data packet includes: the first UE receives retransmission of the D2D data packet according to scheduling of network side equipment or second UE; or, the first UE receives a retransmission of the D2D data packet in the same HARQ process; or, the first UE determines a retransmission position of the D2D data according to the position of the feedback subframe and a second preset interval, where the second preset interval is an interval between the feedback subframe and a retransmission subframe of the D2D data packet, the second preset interval is a fixed time domain interval, and the first UE receives a retransmission of the D2D data packet at the retransmission position of the D2D data.

Further, the receiving, by the first UE, the retransmission of the D2D data packet according to the scheduling of the network side device or the second UE includes: the first UE receives a control signaling sent by a network side device or a control signaling sent by a resource used for scheduling and allocating SA retransmission by a second UE at D2D, the control signaling is used for scheduling retransmission of the D2D data packet, and the first UE receives the retransmission of the D2D data packet according to the indication of the control signaling.

Further, the control signaling includes part or all of the following parameters for indicating retransmission of the D2D data packet: HARQ process number, new data indication NDI, redundancy version RV, time domain and/or frequency domain resource allocation parameters of data retransmission.

Further, the receiving, by the first UE, retransmission of the D2D data packet in the same HARQ process, includes: and the first UE receives the retransmission of the D2D data in a subframe corresponding to the same HARQ process, wherein the subframe corresponding to the same HARQ process is a subframe corresponding to an HARQ process of cellular communication uplink transmission or a subframe corresponding to an HARQ process of D2D communication.

Further, the first UE receives a D2D data packet sent by a second UE, including: the first UE receiving a D2D data packet at a subframe indicated by a bitmap; the first UE receiving the retransmission of the D2D data packet, comprising: the first UE receiving a retransmission of the D2D data packet at a subframe indicated by the bitmap; each bit in the bitmap corresponds to one HARQ process.

In order to solve the above technical problem, the present invention further provides a D2D data packet receiving device, including a first D2D data packet receiving module, a verification module, a first sending module, and a second D2D data packet receiving module, wherein:

the first D2D data packet receiving module is configured to receive a D2D data packet sent by a second UE;

the verification module is used for verifying the D2D data packet;

the first sending module is configured to send feedback information used for indicating a check result, where the feedback information is ACK or NACK;

the second D2D data packet receiving module, configured to receive a retransmission of the D2D data packet when the feedback information is NACK.

In order to solve the above technical problem, the present invention further provides a D2D data packet sending method, including:

the second UE transmitting a D2D data packet to the first UE;

and when receiving feedback information which is used for indicating a checking result and is sent by the first UE and the feedback information is not confirmed NACK, or receiving authorization information which is sent by network side equipment and is used for indicating D2D data packet retransmission, retransmitting the D2D data packet to the first UE.

Further, a subframe in which the first UE sends the feedback information is a feedback subframe, the second UE determines a position of the feedback subframe according to a preset rule or determines a position of the feedback subframe according to an indication in a control signaling, and receives the feedback information in the feedback subframe.

Further, the determining, by the second UE, the position of the feedback subframe according to a preset rule includes: the preset rule is that a third preset interval is arranged between the feedback subframe and the subframe for sending the D2D data packet, the third preset interval is a fixed time domain interval or a minimum time domain interval, and the second UE determines the position of the feedback subframe according to the position of the subframe for sending the D2D data packet and the third preset interval.

Further, the determining, by the second UE, the position of the feedback subframe according to an indication in a control signaling includes: the indication in the control signaling comprises a parameter for indicating the position of the feedback subframe or a parameter for indicating a second feedback interval, where the second feedback interval is an interval between the feedback subframe and a subframe for sending a D2D data packet, the second feedback interval is a fixed time domain interval or a minimum time domain interval, and the second UE determines the position of the feedback subframe according to the indication in the control signaling.

Further, the determining, by the second UE, the position of the feedback subframe according to the minimum time domain interval includes: determining a second available feedback subframe satisfying the minimum time domain interval as a feedback subframe for receiving feedback information, wherein the second available feedback subframe refers to a subframe satisfying at least one of the following conditions: and configuring feedback information transmission resources, wherein the subframes are not D2D data receiving or transmitting subframes of the second UE and are not random access subframes of the second UE.

Further, the retransmitting the D2D data packet to the first UE includes: the second UE determines resources for D2D data packet retransmission according to control signaling sent by the network side equipment, and retransmits the D2D data packet in the resources for D2D data packet retransmission; or, the second UE determines resources for D2D data packet retransmission, sends control signaling for scheduling the D2D data packet retransmission to the first UE, and retransmits the D2D data packet in the resources for D2D data packet retransmission.

Further, the retransmitting the D2D data packet to the first UE includes: the second UE retransmits the D2D data packet in the same hybrid automatic repeat request (HARQ) process, wherein the subframe corresponding to the same HARQ process is a subframe corresponding to an HARQ process of cellular communication uplink transmission or a subframe corresponding to an HARQ process of D2D communication; or, the second UE determines a retransmission position of the D2D data according to a position of a feedback subframe and a fourth preset interval, where the fourth preset interval is an interval between the feedback subframe and a retransmission subframe of the D2D data packet, the fourth preset interval is a fixed time domain interval, and the second UE retransmits the D2D data packet at the retransmission position of the D2D data.

Further, the second UE determining resources for D2D data packet retransmission, sending control signaling to the first UE for scheduling the D2D data packet retransmission, retransmitting the D2D data packet in the resources for D2D data packet retransmission, comprising: the second UE sends control signaling for scheduling D2D data packet retransmission to the first UE on resources for D2D scheduling assignment SA retransmission, and the second UE retransmits the D2D data packet on retransmission resources indicated by the control signaling.

Further, the second UE transmitting the D2D data packet to the first UE, including: the second UE sends a D2D data packet in a subframe indicated by the bitmap; the second UE retransmitting the D2D data packet to the first UE, comprising: the second UE retransmits the D2D data packet in the subframe indicated by the bitmap; each bit in the bitmap corresponds to one HARQ process.

In order to solve the above technical problem, the present invention further provides a device-to-device D2D data packet sending apparatus, including a transmission module and a retransmission module, wherein:

the transmission module is used for transmitting a D2D data packet to the first UE;

the retransmission module is configured to retransmit the D2D data packet to the first UE when receiving feedback information that is sent by the first UE and used for indicating a check result, where the feedback information is NACK or receiving authorization information that is sent by a network side device and used for indicating retransmission of the D2D data packet.

In order to solve the above technical problem, the present invention further provides a D2D communication scheduling method, including:

the method comprises the steps that network side equipment sends first authorization information to second User Equipment (UE), wherein the first authorization information is used for scheduling the second UE to send a D2D data packet to the first UE;

receiving feedback information which is sent by the first UE and used for representing the D2D data packet checking result, wherein the feedback information is Acknowledgement (ACK) or non-acknowledgement (NACK);

and if the received feedback information is NACK, sending second authorization information to the second UE, wherein the second authorization information is used for scheduling the second UE to retransmit the D2D data packet.

Further, receiving feedback information sent by the first UE and used for indicating the D2D data packet verification result includes: the network side equipment determines that a subframe having a fifth preset interval with a subframe for sending a D2D data packet is a feedback subframe for sending feedback information by a first UE, where the fifth preset interval is a fixed time domain interval or a minimum time domain interval, and the network side equipment receives the feedback information sent by the first UE in the feedback subframe.

Further, the determining, by the network side device, that the subframe having the fifth preset interval with the subframe transmitting the D2D data packet is the feedback subframe for the first UE to transmit the feedback information includes: the network side equipment determines a subframe which is separated from a subframe of a D2D data packet sent by the first UE by a fixed time interval as a feedback subframe for receiving feedback information; or, the network side device determines, as a feedback subframe for receiving feedback information, a third available feedback subframe where an interval between the third available feedback subframe and a subframe where the first UE transmits a D2D data packet satisfies a minimum time domain interval, where the third available feedback subframe refers to a subframe that satisfies at least one of the following conditions: and configuring feedback information transmission resources, wherein the subframes are not D2D data receiving or transmitting subframes of the first UE, are not D2D data receiving or transmitting subframes of the second UE, and are not random access subframes.

Further, if the feedback information is NACK, the method further includes: the network side equipment sends a control signaling to the first UE, wherein the control signaling is used for scheduling the first UE to receive retransmission of the D2D data packet; the control signaling includes part or all of the following parameters for indicating retransmission of the D2D data packet: HARQ process number, new data indication NDI, redundancy version RV, time domain and/or frequency domain resource allocation parameters of data retransmission.

In order to solve the above technical problem, the present invention further provides a device-to-device D2D communication scheduling apparatus, including a first scheduling module, a feedback information receiving module, and a second scheduling module, wherein:

the first scheduling module is configured to send first authorization information to a second user equipment UE, where the first authorization information is used to schedule the second UE to send a D2D data packet to the first UE;

the feedback information receiving module is configured to receive feedback information that is sent by the first UE and used for indicating the D2D data packet checking result, where the feedback information is ACK or NACK;

the second scheduling module, when the received feedback information is NACK, is configured to send second grant information to the second UE, where the second grant information is used to schedule the second UE to retransmit the D2D data packet.

The embodiment of the invention can use the existing D2D communication as far as possible, can introduce the D2D unicast communication based on HARQ ACK/NACK feedback and retransmission based on feedback based on the existing D2D transmission mode on the premise of not increasing the complexity of terminal realization and signaling overhead remarkably, improves the spectrum efficiency of D2D by the unicast communication based on HARQ, and enlarges the application range of D2D communication.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the example serve to explain the principles of the invention and not to limit the invention.

Fig. 1 is a schematic diagram of a cellular network deployment in the related art;

fig. 2 is a diagram illustrating a radio resource structure in the related art;

fig. 3 is a flowchart of a D2D data packet receiving method according to an embodiment of the present invention;

fig. 4 is a flowchart of a second D2D data packet sending method according to an embodiment of the present invention;

fig. 5 is a flowchart of a three-D2D communication scheduling method according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a fourth scheduling apparatus according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a fourth receiving device according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a fourth transmitting apparatus according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

The steps illustrated in the flow charts of the figures may be performed in a computer system such as a set of computer-executable instructions. Also, while a logical order is shown in the flow diagrams, in some cases, the steps shown or described may be performed in an order different than here.

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), 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 the OFDMA/SC-FDMA system, a Radio Resource (Radio Resource) for communication is a two-dimensional form of time-frequency. For example, for the LTE/LTE-a system, the communication resources of the uplink and downlink are divided in the time direction by radio frame (radio frame), 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 0.5 ms. And the usual subframes are numbered 0-9 within the radio frame; the radio frames are numbered 0-1023. As shown in fig. 1.

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. Two PRBs adjacent in the time domain within a subframe are called a PRB pair (PRB pair). The Resource corresponding to one subcarrier on each OFDM/SC-FDM symbol is called a Resource Element (RE).

Fig. 2 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 (or referred to as Node bs (Node bs)), or evolved Node bs (enbs), or enhanced Node bs (enbs)), and other network entities (network entities) or network elements (network elements). Alternatively, in general, the Network side may also be referred to as an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) in 3 GPP. The base station herein also includes a Low Power Node (LPN) in a network, such as a femto cell or a Home base station (pico, Relay, femto, HeNB, Home eNB, etc.), and may also be referred to as a small cell (small cell). For simplicity of description, only 3 base stations are shown in fig. 2. A base station provides a certain radio signal coverage area with which terminals (or User Equipments (UEs) or devices) within the coverage area can communicate 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, such as possibly three cells.

Example one

The present embodiment provides a device-to-device packet receiving method, as shown in fig. 3, including the following steps:

step 110, the first UE receives a D2D data packet sent by the second UE;

the first UE may determine, according to an indication in the control signaling sent by the network side device or the second UE, a resource for receiving the D2D data packet, where the D2D data packet sent by the second UE is received. The control signaling sent by the network side device or the second UE carries a parameter for instructing to receive the D2D data packet. The parameter for indicating reception of the D2D packet may be a bitmap (bitmap) indicating the subframe positions where the D2D packet is received.

Step 120, the first UE checks the received D2D data packet and sends feedback information indicating a check result, where the feedback information is an Acknowledgement (ACK) or a Negative Acknowledgement (NACK); receiving a retransmission of the D2D data packet if the feedback information is a NACK.

The first UE may send the feedback information to the second UE or to the network side device. A subframe for transmitting ACK or NACK (hereinafter, abbreviated as ACK/NACK) feedback information is a feedback subframe. When the first UE sends feedback information to the second UE, the feedback subframe is one of the following subframes: an uplink subframe or a downlink subframe of a cellular communication system, the uplink subframe or the downlink subframe being configured with a feedback resource (i.e. a feedback information transmission resource); the subframe indicated by the control signaling. When the first UE sends feedback information to the base station, the feedback subframe is one of the following subframes: an uplink subframe of a cellular communication system, the uplink subframe being configured with a feedback resource (i.e. a feedback information transmission resource); the subframe indicated by the control signaling.

Based on the Rel-12D2D SA (Scheduling Assignment) period, HARQ feedback information of the D2D data packet is transmitted in the SA period in which the data is transmitted. However, the rule for blindly retransmitting each packet 4 times in Rel-12 needs to be redefined: whether retransmission depends on received ACK/NACK feedback, if the check result is ACK, retransmission is not needed, and if the check result is NACK, feedback information is sent in a feedback subframe. The feedback subframe may be determined according to a preset rule or according to an indication in the control signaling. The following description will be made separately.

In a first mode, the first UE determines the position of a feedback subframe according to a preset rule

1 a: the predetermined rule is that there is a first predetermined interval between the feedback sub-frame and the sub-frame for receiving the D2D data packet, and the first predetermined interval is a fixed time domain interval.

For example, if the ue receives the D2D data packet at the subframe n, it determines that the subframe n + k having a fixed interval k with the D2D data packet is used for transmitting ACK/NACK feedback information, where k is an integer. For example, k is 3, 4, 5, etc. Or, the value of k is related to the duplex mode, for example, the values of the frequency division duplex FDD system and the time division duplex TDD system may be different; for the TDD system, the value of k may be a fixed value, or the value of k includes multiple values, and the values of k may be different for different TDD uplink and downlink configurations (UL-DL configurations).

The subframe n and the subframe n + k may be for all subframes (such as all uplink subframes or all downlink subframes), or for subframes in a specific set of subframes. For the former, the interval k is an actual interval, e.g., k is 4, and then the interval between the subframe n and the subframe n + k is 4 milliseconds (ms) under the assumption that the subframe duration is 1 ms. For the latter, the actual spacing may be different from the value of k. For example, a part of subframes (which form a subframe set) in the uplink subframe is allocated for D2D communication (which may be allocated for D2D data transmission and feedback information transmission, or only for feedback information transmission), and the position of the subframe n + k is determined based on the subframes in the subframe set and the k value. For example, if the subframe set includes subframes numbered 1, 2, 4, 6, 8, and 9, then for the transmission of the D2D packet in subframe 2, if k is 4, its feedback information is transmitted in subframe 9, that is, only the subframes in the subframe set are considered when calculating the interval k.

In this approach, the ACK/NACK feedback of the D2D UE has the highest priority, i.e. if colliding with other transmissions, the other transmissions are dropped. For example, if a packet that needs to be received is found in the feedback, the UE considers that this is a scheduling error (error case); if the feedback has the packets needing to be sent, if the feedback is sent to the same UE, the ACK/NACK can be transmitted after being multiplexed, and if the feedback is sent to other UEs, the sending of other UEs is cancelled. Specifically, the method comprises the following steps:

(1) when the first UE has a D2D reception requirement at the same subframe as the subframe sending the feedback information, for example, the determined feedback subframe is n + k, but the control signaling sent by the base station or other UEs indicates that the subframe n + k is the D2D reception subframe of the first UE, the first UE may send only ACK/NACK feedback information and abandon D2D reception.

(2) When the first UE has a D2D transmission requirement at the same subframe for transmitting the feedback information, for example, the determined feedback subframe is n + k, but a control signaling sent by the base station or another UE indicates that the subframe n + k is a D2D data transmission subframe of the first UE, and the transmitted target UE is different from the target UE to which the feedback information is transmitted (in this example, is a non-second UE), the first UE may send only ACK/NACK feedback information and abandon sending D2D data to the non-feedback information target UE.

(3) When the first UE has a D2D transmission requirement at the same subframe for transmitting the feedback information, for example, the determined feedback subframe is n + k, but a control signaling sent by the base station or another UE indicates that the subframe n + k is a D2D data transmission subframe of the first UE, and the transmitted target UE is the same as the target UE (in this example, the second UE) for transmitting the feedback information, the first UE may multiplex the ACK/NACK feedback information with the D2D data and transmit the multiplexed ACK/NACK feedback information. For example, the multiplexing mode may be similar to a multiplexing mode of ACK/NACK information in a Physical Uplink Shared Channel (PUSCH) in an LTE system.

1 b: the predetermined rule is that there is a first predetermined interval between the feedback sub-frame and the sub-frame for receiving the D2D data packet, and the first predetermined interval is a minimum time domain interval.

In this embodiment, a first available feedback subframe satisfying the minimum time domain interval is determined, and ACK/NACK feedback information is transmitted in the first feedback subframe. The first available feedback subframe refers to a subframe satisfying at least one of the following conditions: a subframe configured with feedback information transmission resources or indicated as a feedback information transmission subframe; a cellular communication data reception or transmission subframe of a non-first UE; a D2D data reception or transmission subframe for a non-first UE; a random access subframe other than the first UE. Preferably, the first available feedback subframe is determined as the subframe position of the feedback information transmission, i.e. the UE transmits the feedback information in the first subframe not colliding with D2D transmission/reception.

For example, the minimum time domain interval is k (may take a positive integer value, such as 3 or 4 or 5). After receiving the D2D data in the subframe n, the ue transmits ACK/NACK feedback information of the D2D data in a first available feedback subframe after the subframe n + k (the n + k subframe itself is not included here, and other embodiments may also include depending on the value of k). For example, the available feedback subframes are subframes 1, 2, 4, 6, 8, 9, and k is 3; after receiving the D2D data in subframe 1, the first UE transmits ACK/NACK information in the first available feedback subframe after subframe 4, since the first available feedback subframe after subframe 4 is subframe 6, that is, the first UE transmits feedback information in subframe 6.

Specifically, the subframe configured with the feedback information transmission resource refers to a resource configured or preconfigured by the network side device for D2D feedback information transmission in the subframe. The feedback information transmission resources may be configured in a part of subframes, for example, the network side configures or pre-configures the feedback information transmission resources in a part of subframes, or the feedback information transmission resources in all subframes (all downlink subframes or all uplink subframes).

For example, after receiving the D2D data, the first UE needs to send corresponding feedback information to the D2D data sender (the second UE). It is assumed that subframes 1, 3, 6, 7, 8 are configured with feedback resources and still that k is 3. Then if the first UE receives D2D data in subframe 1, the corresponding ACK/NACK feedback information needs to be sent after subframe 4. Meanwhile, assuming that the subframe 6 is a D2D reception subframe of the first UE, that is, the subframe 6 needs to receive D2D data sent by other UEs (second UE or other UEs), the subframe 6 cannot be used for feedback information transmission, that is, the subframe 6 is not an available feedback subframe of the first UE, and it needs to be determined that a subframe after the subframe 6 is used for transmission of ACK/NACK feedback information.

In the second mode, the first UE determines the position of the feedback subframe according to the indication in the control signaling

The indication in the control signaling sent by the eNB or the sending-end UE includes a parameter for indicating a position of a feedback subframe or includes a parameter for indicating a first feedback interval, in this embodiment, the first feedback interval is an interval between the feedback subframe and a subframe for receiving the D2D data packet, the first feedback interval may be a fixed time domain interval or a minimum time domain interval, and the first UE determines the position of the feedback subframe according to the indication in the control signaling.

2 a: and the subframe for sending the ACK/NACK feedback information is a feedback subframe indicated by control signaling. For example, the first UE receives a control signaling sent by a network side device or the second UE, where the control signaling carries a parameter for indicating a subframe position for transmitting the feedback information; and the user equipment sends the feedback information according to the indication of the parameters.

For example, a subframe position where the feedback information is transmitted is indicated by a bitmap (bitmap); the bitmap may be the same as a bitmap indicating a D2D data Transmission subframe (i.e., a subframe indicating reception of a D2D data packet), such as T-RPT in LTE Release-12D2D, Time-Resource Pattern of Transmission, or may be a different parameter. If the bitmap is the same parameter as the bitmap indicating the D2D data transmission subframe, it may be agreed that "1" indicating a specific bit position in the bitmap indicates the position of the feedback information transmission subframe. For example, the last "1" in the bitmap indicates the feedback information transmission subframe position; or "1" in an odd (or even) position in the bitmap indicates a feedback information transmission subframe position, where the odd position refers to a subframe position corresponding to the mth "1" in the bitmap, and m is an odd number, or a subframe position corresponding to the mth bit in the bitmap, and m is an odd number; or, a "1" appearing in the second half of the bitmap indicates a feedback information transmission subframe position (for example, the bitmap length is 8 bits, and the second half refers to the last 4 bits); and the like.

2 b: and determining the subframe for sending the ACK/NACK feedback information according to the indication of a control signaling, wherein the control signaling comprises a parameter for indicating a first feedback interval. For example, the first UE receives a control signaling sent by a network side device or the second UE, where the control signaling carries a parameter for indicating a first feedback interval, where the first feedback interval represents an interval between a subframe for transmitting the feedback information and the data transmission subframe (i.e., a subframe in which the first UE receives the D2D data packet); and the first UE determines the position of a subframe for transmitting the feedback information according to the interval and sends the feedback information in the subframe.

The indicated first feedback interval may be defined similarly to the first preset interval in the first mode, that is, the first feedback interval may be a fixed time domain interval or a minimum time domain interval, but the first feedback interval is different from the aforementioned first preset interval in that the first feedback interval is an interval value indicated by control signaling, and the first preset interval is a predefined or preconfigured interval value; after determining the interval value based on the indicated first feedback interval, a specific manner of determining the feedback subframe may be the same as the aforementioned manner of determining the feedback subframe based on the first preset interval.

If the Control signaling indicating the first feedback interval is sent by a network side device, the Control signaling may be a physical layer signaling, for example, carried in DCI (Downlink Control Information); it may also be higher layer signaling, such as carried in dedicated RRC (Radio resource control) signaling, or such as carried in broadcast Signaling (SIB).

After receiving the D2D data packet and sending the feedback information, the first UE waits to receive a retransmission of the data packet if the feedback information is NACK. There are three ways to determine the retransmission location.

Mode 1: after the first UE sends the feedback information, retransmission receiving is carried out according to the scheduling of the network side equipment or the second UE;

in this approach, the first UE detects control signaling for scheduling retransmission of the data packet. The control signaling may be sent by the base station, for example, the base station sends Downlink Control Information (DCI) to schedule data transmission and retransmission of the D2D link; or the sending end UE (i.e. sent by the second UE), such as Sidelink Control Information (SCI), which may also be referred to as Scheduling Assignment (SA)). And after detecting the control signaling, the first UE receives the retransmission data of D2D according to the indication of the control signaling.

Part or all of the following parameters may be included in the control signaling: HARQ process number (HARQ process number) of the D2D link, New Data Indicator (NDI), Redundancy Version (Redundancy Version, RV), time domain and/or frequency domain resource allocation parameters for Data retransmission, Orthogonal mask (OCC), identification (Identifier, ID) of a sender (e.g., a second UE) of the D2D packet, and ID of a receiver (e.g., a first UE) of the D2D packet. The above parameters are not necessarily carried, and may be determined by convention or other implicit means.

1 a: the D2D data packet sender UE sends control signaling, and may send control Signaling (SA) for scheduling D2D data packet retransmission at the resource for D2D SA retransmission. For example, the SA in the D2D communication will be transmitted 2 times in each SA cycle, and then the SA for the first transmission is used to schedule the first transmission of the D2D data packet, and the SA for the second transmission (i.e., the SA for retransmission) is used to schedule the retransmission of the D2D data packet.

Further, in addition to the above-described embodiments, there are also preferred embodiments as follows:

(1) the number of transmissions of the SA within a period is increased for scheduling the retransmission of the D2D data packet. For example, assuming that the maximum number of transmissions in a period allowed by a D2D packet is p (i.e., p-1 retransmissions can be performed at most), it may be agreed that each SA in the period can transmit p times (or p transmissions at most), where the first transmission can be used to schedule the first transmission of the D2D packet and the remaining transmissions are used to schedule the retransmission of the D2D packet. If the D2D data packet is received correctly (i.e. the feedback information is ACK) at the first transmission time, the transmission of other D2D data packets can be continued in the period; or, only one D2D data packet is transmitted in each period, and if the D2D data packet is received correctly during the first transmission, the transmission of other D2D data packets needs to wait until the next period. When a plurality of parallel HARQ processes are supported, for a certain HARQ process, if the D2D data packet is received correctly (namely, the feedback information is ACK) during first transmission, other transmission subframes corresponding to the HARQ process in the period can continue to transmit other D2D data packets; or, it is stipulated that each HARQ process only transmits one D2D data packet in each period, and if the D2D data packet is received correctly during first transmission, it is necessary to wait for the next period before performing transmission of other D2D data packets in the subframe corresponding to the HARQ process.

It should be noted that the p value may be fixed, for example, the value of p is the same no matter how many SA cycles are; or the p value is determined according to the size of the SA cycle, for example, when the SA cycle is 40ms, the p value is 4, and when the SA cycle is 80ms, the p value is 8, and so on.

(2) And carrying a new data indication in the control signaling for indicating the first transmission or the retransmission, wherein the bit number of the new data indication can be determined according to the schedulable HARQ process number. For example, at most 8 HARQ processes can be scheduled, the length of the NDI indication signaling is 8 bits, and each bit corresponds to one HARQ process.

Further, the new data indication may also be used in combination with a bitmap indicating the HARQ process, for example, an 8-bit bitmap indicates whether the corresponding HARQ process has data scheduled, and further, whether the scheduled HARQ process is the first transmission or the retransmission is determined according to the NDI.

(3) The first transmission or retransmission may also be implicitly indicated by the RV. For example, the RV sequence of the data packet transmission is agreed to be [0213], when the indicated RV version is 0, the first transmission of the D2D data packet is indicated, when the RV version is 1, the second transmission (i.e., the first retransmission) of the D2D data packet is indicated, and so on.

1 b: the control signaling comprises time domain and/or frequency domain resource allocation parameters of data retransmission, and the D2D data packet is transmitted in the time domain and/or frequency domain resources indicated by the resource allocation parameters.

And if the control signaling does not comprise the time domain and/or frequency domain resource allocation parameters of data retransmission, the time domain and/or frequency domain resources transmitted by the D2D data packet are the same as the first transmission position. Specifically, if the time domain resource allocation parameter is not included, the time domain resource of the D2D data packet during retransmission is the same as that of the first transmission; if the frequency domain resource allocation parameters are not included, the frequency domain resources when the D2D data packet is retransmitted are the same as the first transmission; and so on. The time domain is the same, that is, the subframe for transmitting the D2D data packet is a subframe corresponding to the same HARQ process (where the HARQ process refers to a D2D HARQ process, or a cellular communication HARQ process, such as a cellular uplink HARQ process); or, the position of the subframe transmitting the D2D data packet in the transmission period is the same, for example, the first transmission is in the 1 st subframe in the transmission period, and then in the 1 st subframe in the next transmission period during retransmission, the transmission period may be kept the same as the SA period, or the SA period is divided. The frequency domain identity refers to that the frequency domain position for transmitting the D2D data packet is the same as the frequency domain position used for the initial transmission or the last transmission, or is determined according to the position of the initial transmission or the last transmission and a frequency hopping (frequency hopping) rule.

Mode 2: after the first UE sends the feedback information, if the feedback information is NACK, the retransmission reception is performed strictly and synchronously, that is, the first UE receives the retransmission of the D2D data packet in the same HARQ process, and the HARQ RTT (Round Trip Time ) is fixed;

the HARQ transmission adopts a synchronous HARQ transmission mode, wherein the synchronous means that the subframe positions of multiple data transmissions corresponding to the same HARQ process are fixed.

And the first UE receives the retransmission of the D2D data in a subframe corresponding to the same HARQ process. And if the control signaling comprises the parameter for indicating the HARQ process number, the retransmission and the first transmission have the same HARQ process number.

Specifically, the subframe corresponding to the same HARQ process is a subframe corresponding to an HARQ process of cellular communication uplink transmission. For example, for an FDD system, the uplink has 8 HARQ processes in total, that is, subframes spaced by 8 subframes belong to the same HARQ process, for example, subframe n +8, subframe n +16, and … belong to the same HARQ process. Therefore, when the check result of the D2D data packet received by the UE in the subframe n is NACK, the data packet is retransmitted in the subframe n +8, and the UE at the transmitting end and the UE at the receiving end respectively transmit and receive the retransmission of the D2D data packet in the subframe n + 8.

Or the subframe corresponding to the same HARQ process is a subframe corresponding to the HARQ process of D2D communication. For example, the number of HARQ processes of the D2D link is N, and the numbers of the D2D subframes are 0, 1, 2, and … (the D2D subframe may be all subframes within a certain starting and ending range, for example, all downlink subframes or all uplink subframes, or may be a part of subframes allocated in the cellular communication resource, for example, a part of cellular uplink subframes is allocated as a D2D subframe), the numbers of the D2D subframes are modulo N, and as a result, the same subframes all belong to the same D2D HARQ process. For example, if the number N of HARQ processes of the D2D link is 6, for example, the D2D subframes numbered 1, 7, 13, and … belong to the same HARQ process. Therefore, when the check result of the D2D data packet transmitted in the D2D subframe 1 is NACK, the transmitting end of the D2D data packet retransmits the D2D data packet in the D2D subframe 7, and the receiving end receives the D2D data packet in the subframe 7.

Specifically, the subframe of D2D data transmission is indicated by using a bitmap, where each bit in the bitmap corresponds to one HARQ process. For example, the bitmap has a length of M, and each bit in the bitmap corresponds to 1 set of subframes. Assuming that the numbers of the D2D subframes are 0, 1, 2, … (the meaning of the D2D subframes may be the same as in the above example), the numbers of the D2D subframes are modulo M, and the modulo result corresponds to the corresponding bit in the bitmap. Assuming that M is 12 and the bitmap for scheduling D2D data transmission is 001000000000, HARQ processes corresponding to subframes numbered 2, 14, and … are used for transmitting the D2D data packet, and if the check result of the D2D data packet transmitted in subframe 2 is NACK, the retransmission is performed in subframe 14, and so on, which is not described again.

Mode 3: after the first UE sends the feedback information, determining a retransmission position of the D2D data according to a position of a feedback subframe and a second preset interval, and synchronously performing retransmission reception, where the second preset interval is an interval between the feedback subframe and a retransmission subframe of a D2D data packet, and the second preset interval is a fixed time domain interval, and the first UE receives a retransmission of the D2D data packet at the retransmission position of the D2D data (that is, receives a retransmission in a next subframe (or an available subframe) that satisfies the second preset interval);

when the check result is NACK, the retransmission position of the D2D data is determined according to the subframe position of the feedback information transmission, such as the retransmission of the device-to-device communication data is transmitted in the D2D subframe having the second predetermined interval with the feedback subframe. Further, the second predetermined interval may be a fixed interval value; the D2D subframes may be all subframes (such as all uplink subframes within a particular starting and ending range), or subframes configured for D2D data transmission. If the D2D subframe is all subframes, the D2D data packet is transmitted in a subframe having a fixed interval from a feedback information transmission subframe. If the D2D subframe is a subframe configured for D2D data transmission, the D2D data packet is transmitted in the first (available) D2D data transmission subframe after a fixed interval of the feedback information transmission subframe; at this time, only the subframe of D2D data transmission is calculated at a fixed interval, or all subframes, for example, all uplink subframes, are calculated. The sub-frame of the D2D data transmission is calculated at fixed intervals, that is, the D2D data packet is transmitted in the first (available) D2D data transmission sub-frame after the fixed-interval D2D data transmission sub-frame of the feedback information transmission sub-frame; the fixed interval calculation of all uplink subframes means that the D2D data packet is transmitted in the first (available) D2D data transmission subframe after the fixed interval subframes (all uplink subframes, including the configured D2D data transmission subframe) of the feedback information transmission subframe.

In another preferred embodiment, the first UE may receive the D2D data packet and the retransmission of the D2D data packet in the subframe indicated by the bitmap, which is indicated in the manner described above, where each bit in the bitmap corresponds to one HARQ process.

Example two

The embodiment provides a D2D packet sending method, as shown in fig. 4, which includes the following steps:

step 210, the second UE transmits a D2D data packet to the first UE;

the second UE may transmit D2D data packets to the first UE according to the scheduling of the base station.

Step 220, when the second UE receives the feedback information indicating the check result and the feedback information is NACK, sent by the first UE, or receives the authorization information indicating the D2D data packet retransmission, sent by the network side device, and retransmits the D2D data packet to the first UE.

The present embodiment is a transmission method corresponding to the first receiving method of the first embodiment, where the two methods have related correspondences, and various implementations of the method of the present embodiment can refer to the description and examples in the first embodiment.

And the subframe in which the first UE sends the feedback information is a feedback subframe. The following two ways to determine the position of the feedback subframe are available:

the first method is as follows: and the second UE determines the position of the feedback subframe according to a preset rule and receives the feedback information in the feedback subframe.

The preset rule is that a third preset interval is arranged between the feedback subframe and the subframe for sending the D2D data packet, the third preset interval is a fixed time domain interval or a minimum time domain interval, and the second UE determines the position of the feedback subframe according to the position of the subframe for sending the D2D data packet and the third preset interval. The third preset interval preset for the UE2 is the same as the first preset interval preset for the UE1 during the same D2D data transmission. The specific implementation can be found in the related description and examples of the first preset interval in the first embodiment.

When the third preset interval is the minimum time domain interval, the second UE determines a second available feedback subframe satisfying the minimum time domain interval as a feedback subframe for receiving feedback information, where the second available feedback subframe is a subframe satisfying at least one of the following conditions: and configuring feedback information transmission resources, wherein the subframes are not D2D data receiving or transmitting subframes of the second UE and are not random access subframes of the second UE.

The second method comprises the following steps: and the second UE determines the position of the feedback subframe according to the indication in the control signaling, and receives the feedback information in the feedback subframe.

The indication in the control signaling comprises a parameter for indicating the position of the feedback subframe or a parameter for indicating a second feedback interval, where the second feedback interval is an interval between the feedback subframe and a subframe for sending a D2D data packet, the second feedback interval is a fixed time domain interval or a minimum time domain interval, and the second UE determines the position of the feedback subframe according to the indication in the control signaling. The second feedback interval sent to UE2 is the same as the first feedback interval sent to UE1 during the same D2D data transmission. The specific implementation can be referred to the related description and examples of the first feedback interval in the first embodiment.

At this time, when the second feedback interval is the minimum time domain interval, the second UE determines a second available feedback subframe satisfying the minimum time domain interval as a feedback subframe for receiving feedback information.

The second UE retransmits the D2D data packet to the first UE in one of the following manners:

in a first mode, the second UE determines a resource for retransmission of the D2D data packet according to a control signaling sent by the network side device, and retransmits the D2D data packet in the resource for retransmission of the D2D data packet;

for example, the base station sends DCI scheduling D2D data retransmission, and part or all of the following parameters may be carried in the DCI to indicate the retransmission resource location of the D2D data packet: HARQ process number, new data indication NDI, redundancy version RV, time domain and/or frequency domain resource allocation parameters of data retransmission. Specific examples can be found in the description of embodiment one.

Second, the second UE determines resources for D2D data packet retransmission, sends control signaling for scheduling the D2D data packet retransmission to the first UE, and retransmits the D2D data packet in the resources for D2D data packet retransmission.

Specifically, the second UE may determine resources for retransmission of the D2D data packet according to scheduling on the network side, and send control signaling for scheduling retransmission of the D2D data packet to the first UE on the resources for scheduling SA retransmission allocation on the D2D, while the second UE retransmits the D2D data packet on the retransmission resources indicated by the control signaling.

In a third mode, the second UE retransmits the D2D data packet in the same HARQ process, where the subframe corresponding to the same HARQ process is a subframe corresponding to an HARQ process of cellular communication uplink transmission or a subframe corresponding to an HARQ process of D2D communication;

in a fourth mode, the second UE determines a retransmission position of the D2D data according to a position of a feedback subframe and a fourth preset interval, where the fourth preset interval is an interval between the feedback subframe and a retransmission subframe of the D2D data packet, the fourth preset interval is a fixed time domain interval, and the second UE retransmits the D2D data packet at the retransmission position of the D2D data.

The fourth preset interval preset for the UE2 is the same as the second preset interval preset for the UE1 during the same D2D data transmission. The specific implementation can be referred to the second preset interval related description and examples in the first embodiment.

In a preferred embodiment, the second UE transmits a D2D data packet and retransmits the D2D data packet in a subframe indicated by a bitmap, where each bit corresponds to a HARQ process.

In a preferred embodiment, the second UE may use a non-adaptive retransmission scheme when retransmitting the D2D data packet. When non-adaptive retransmission is adopted, the RV can adopt a fixed RV sequence; the frequency domain resource location may be the same as the first transmission, or determined according to the frequency domain resource location and frequency hopping (frequency hopping) rule of the first transmission.

EXAMPLE III

The present embodiment provides a D2D communication scheduling method, as shown in fig. 5, including:

step 310, a network side device sends first authorization information to a second UE, where the first authorization information is used to schedule the second UE to send a D2D data packet to a first UE;

step 320, receiving feedback information which is sent by the first UE and used for indicating the D2D data packet checking result, where the feedback information is ACK or NACK;

step 330, if the received feedback information is NACK, sending second grant information to the second UE, where the second grant information is used to schedule the second UE to retransmit the D2D data packet.

In step 320, the network side device determines that a subframe having a fifth preset interval with a subframe transmitting the D2D data packet is a feedback subframe for the first UE to transmit feedback information, where the fifth preset interval is a fixed time domain interval or a minimum time domain interval, and the network side device receives the feedback information transmitted by the first UE in the feedback subframe. The feedback subframe is an uplink subframe or a downlink subframe of a cellular communication system, or an uplink subframe or a downlink subframe configured with feedback resources, or a subframe sending the ACK/NACK feedback information is a feedback subframe indicated by the authorization information.

Specifically, when the fifth preset interval is a fixed time domain interval, the network side device determines that a subframe which is separated by a fixed time interval from a subframe at which the first UE sends the D2D data packet is a feedback subframe for receiving feedback information; wherein the feedback information is transmitted in a feedback resource of the feedback subframe; or, the feedback information is multiplexed in the cellular communication data or the cellular link uplink feedback information sent by the first UE to the network side device for transmission. When a fifth preset interval is a minimum time domain interval, the network side device determines, as a feedback subframe for receiving feedback information, a third available feedback subframe, where an interval between subframes where D2D data packets are sent by the first UE and the subframe meets the minimum time domain interval, where the third available feedback subframe is a subframe meeting at least one of the following conditions: and configuring feedback information transmission resources, wherein the subframes are not D2D data receiving or transmitting subframes of the first UE, are not D2D data receiving or transmitting subframes of the second UE, and are not random access subframes.

For implementation of the fifth preset interval, refer to the related description of the first preset interval in the first embodiment.

If the feedback information is NACK, the method further comprises the steps of: the network side equipment sends a control signaling to the first UE, wherein the control signaling is used for scheduling the first UE to receive retransmission of the D2D data packet; the control signaling includes part or all of the following parameters for indicating retransmission of the D2D data packet: HARQ process number, new data indication NDI, redundancy version RV, time domain and/or frequency domain resource allocation parameters of data retransmission.

The transmission of the feedback information and the retransmission of the D2D data packet refer to the foregoing embodiments.

Example four

The present embodiments provide a system for device-to-device communication, comprising: a network side device, a first user equipment and a second user equipment of a cellular network. The above-described entities will be described separately below.

In one embodiment, the network side device of the cellular network may be a base station as described in the previous example. The network side device includes a scheduling apparatus as shown in fig. 6, and the apparatus may include at least: a first scheduling module 410, a feedback information receiving module 420, and a second scheduling module 430, wherein:

the first scheduling module 410 is configured to send first grant information to a second UE, where the first grant information is used to schedule the second UE to send a D2D data packet to the first UE;

the feedback information receiving module 420 is configured to receive feedback information that is sent by the first UE and used for indicating the D2D data packet checking result, where the feedback information is ACK or NACK;

the second scheduling module 430, configured to send second grant information to the second UE when the received feedback information is NACK, where the second grant information is used to schedule the second UE to retransmit the D2D data packet.

The subframe in which the first UE sends the feedback information is a feedback subframe, where the feedback subframe is an uplink subframe or a downlink subframe of a cellular communication system, or an uplink subframe or a downlink subframe configured with feedback resources, or a subframe sending the ACK/NACK feedback information is a feedback subframe indicated by the authorization information.

In a preferred embodiment, the feedback information receiving module 420 determines a subframe having a fifth preset interval with a subframe transmitting the D2D data packet as a feedback subframe for transmitting feedback information by the first UE, where the fifth preset interval is a fixed time domain interval or a minimum time domain interval, and the feedback information receiving module 420 receives the feedback information transmitted by the first UE in the feedback subframe.

When the fifth preset interval is a fixed time domain interval, the feedback information receiving module 420 determines that a subframe separated by a fixed time interval from a subframe in which the first UE sends a D2D data packet is a feedback subframe for receiving feedback information; or,

when the fifth preset interval is the minimum time domain interval, the feedback information receiving module 420 determines, as a feedback subframe for receiving feedback information, a third available feedback subframe, where an interval between subframes where D2D data packets are sent by the first UE and the subframe meets the minimum time domain interval, where the third available feedback subframe is a subframe meeting at least one of the following conditions: and configuring feedback information transmission resources, wherein the subframes are not D2D data receiving or transmitting subframes of the first UE, are not D2D data receiving or transmitting subframes of the second UE, and are not random access subframes.

In a preferred embodiment, when the feedback information is NACK, the second scheduling module 430 is further configured to send control signaling to the first UE, where the control signaling is used to schedule the first UE to receive a retransmission of a D2D data packet; the control signaling includes part or all of the following parameters for indicating retransmission of the D2D data packet: HARQ process number, new data indication NDI, redundancy version RV, time domain and/or frequency domain resource allocation parameters of data retransmission.

In an embodiment, the network side device may be a base station (base station or eNB), or other network access device such as a small cell, or may be a network node of an upper layer, such as a gateway (gateway), or a Mobility Management Entity (MME), or other server or network unit that provides services for D2D, or may include one or more of the above nodes.

In another embodiment, the network-side device may also be a temporarily deployed network element in a non-coverage scenario. The non-coverage scene refers to a scene that the user equipment is in a coverage hole of the cellular network, such as a damaged cellular infrastructure, or a coverage hole area.

In another embodiment, the network side device may also be a UE acting as a Cluster Head (Cluster Head) or a primary UE (primary UE), for example, in some specific scenarios, such as scenarios without network coverage, a specific UE configures device discovery resources.

In one embodiment, the first UE includes a receiving apparatus as shown in fig. 7, which may include at least: a first D2D packet receiving module 510, a verification module 520, a first sending module 530, and a second D2D packet receiving module 540, wherein:

the first D2D data packet receiving module 510, configured to receive a D2D data packet sent by a second UE;

the verification module 520 is configured to verify the D2D data packet;

the first sending module 530 is configured to send feedback information used for indicating a check result, where the feedback information is ACK or NACK;

the second D2D data packet receiving module 540, configured to receive a retransmission of the D2D data packet when the feedback information is NACK.

In a preferred embodiment, the subframe for sending the feedback information is a feedback subframe, and the first sending module 530 is further configured to determine the position of the feedback subframe according to a preset rule to determine the position of the feedback subframe. The preset rule is that a first preset interval is provided between the feedback subframe and the subframe receiving the D2D data packet, the first preset interval is a fixed time domain interval or a minimum time domain interval, and the first sending module 530 determines the position of the feedback subframe according to the position of the subframe receiving the D2D data packet and the first preset interval.

Preferably, the apparatus further comprises a determining module 550, configured to, after the first sending module 530 determines the feedback subframe position according to the subframe position of receiving the D2D data packet and the first preset interval, determine that if there is a D2D data reception requirement in the determined feedback subframe, notify the first D2D data packet receiving module 510 and the second D2D data packet receiving module 540 to drop D2D data reception; determining whether there is a D2D data transmission requirement in the determined feedback subframe and the target UE of D2D data transmission is not the second UE, notifying the first transmitting module 530 to abandon D2D data transmission; and if the determined feedback subframe has a D2D data transmission requirement and the target UE for D2D data transmission is the second UE, notifying the first transmitting module 530 to multiplex the feedback information with the D2D data and then transmit the multiplexed feedback information in the feedback subframe.

Preferably, when the first preset interval is a minimum time domain interval, the first transceiver module 530 determines a first available feedback subframe satisfying the minimum time domain interval as a feedback subframe for sending feedback information, where the first available feedback subframe refers to a subframe satisfying at least one of the following conditions: a subframe configured with feedback information transmission resources or indicated as a feedback information transmission subframe, a cellular communication data reception or transmission subframe other than the first UE, a D2D data reception or transmission subframe other than the first UE, a random access subframe other than the first UE.

In another preferred embodiment, the first sending module 530 is further configured to determine the position of the feedback subframe according to an indication in a control signaling. The indication in the control signaling includes a parameter for indicating a position of a feedback subframe, or includes a parameter for indicating a first feedback interval, where the first feedback interval is an interval between the feedback subframe and a subframe receiving the D2D data packet, the first feedback interval is a fixed time domain interval or a minimum time domain interval, and the first sending module 530 determines the position of the feedback subframe according to the indication in the control signaling.

Preferably, when the first feedback interval is a minimum time domain interval, the first transceiver module 530 determines that a first available feedback subframe satisfying the minimum time domain interval is a feedback subframe for sending feedback information.

In another preferred embodiment, the second D2D packet receiving module 540 receives the retransmission of the D2D packet by one of:

in a first manner, the second D2D data packet receiving module 540 receives the retransmission of the D2D data packet according to the scheduling of the network side device or the second UE;

specifically, the second D2D data packet receiving module 540 receives a control signaling sent by a network side device or a control signaling sent by a second UE in a resource for D2D SA retransmission, where the control signaling is used to schedule retransmission of the D2D data packet, and the second D2D data packet receiving module receives retransmission of the D2D data packet according to an indication of the control signaling. The control signaling includes part or all of the following parameters for indicating retransmission of the D2D data packet: HARQ process number, new data indication NDI, redundancy version RV, time domain and/or frequency domain resource allocation parameters of data retransmission.

In a second manner, the second D2D data packet receiving module 540 receives the retransmission of the D2D data packet in the same HARQ process;

specifically, the second D2D data packet receiving module 540 receives the retransmission of the D2D data in a subframe corresponding to the same HARQ process, where the subframe corresponding to the same HARQ process is a subframe corresponding to an HARQ process of cellular communication uplink transmission or a subframe corresponding to an HARQ process of D2D communication.

In a third manner, the second D2D data packet receiving module 540 determines a retransmission position of the D2D data according to the position of the feedback subframe and a second preset interval, where the second preset interval is an interval between the feedback subframe and a retransmission subframe of the D2D data packet, the second preset interval is a fixed time domain interval, and the second D2D data packet receiving module 540 receives a retransmission of the D2D data packet at the retransmission position of the D2D data.

In a preferred embodiment, the first D2D data packet receiving module 510 receives a D2D data packet transmitted by a second UE, including: the first D2D packet receiving module 510 receives a D2D packet at a subframe indicated by a bitmap; the second D2D packet receiving module 540 receives the retransmission of the D2D packet, including: the second D2D data packet receiving module 540 receives a retransmission of the D2D data packet at a subframe indicated by the bitmap; each bit in the bitmap corresponds to one HARQ process.

In one embodiment, the second UE is a transmitting apparatus as shown in fig. 8, and the transmitting apparatus may include at least: a transmission module 610 and a retransmission module 620, wherein:

the transmitting module 610 is configured to transmit a D2D data packet to the first UE;

the retransmission module 620 is configured to retransmit the D2D data packet to the first UE when receiving the feedback information that is sent by the first UE and used for indicating the check result, where the feedback information is NACK or receiving authorization information that is sent by a network side device and used for indicating retransmission of the D2D data packet.

And the subframe in which the first UE sends the feedback information is a feedback subframe.

In a preferred embodiment, the retransmission module 620 determines the position of the feedback subframe according to a preset rule, and receives the feedback information in the feedback subframe.

The preset rule is that a third preset interval is provided between the feedback subframe and the subframe transmitting the D2D data packet, the third preset interval is a fixed time domain interval or a minimum time domain interval, and the retransmission module 620 determines the position of the feedback subframe according to the position of the subframe transmitting the D2D data packet and the third preset interval.

When the third preset interval is the minimum time domain interval, the retransmission module 620 determines a second available feedback subframe that satisfies the minimum time domain interval as a feedback subframe for receiving feedback information, where the second available feedback subframe is a subframe that satisfies at least one of the following conditions: and configuring feedback information transmission resources, wherein the subframes are not D2D data receiving or transmitting subframes of the second UE and are not random access subframes of the second UE.

In another preferred embodiment, the retransmission module 620 determines the position of the feedback subframe according to the indication in the control signaling, and receives the feedback information in the feedback subframe.

The indication in the control signaling includes a parameter for indicating the position of the feedback subframe, or includes a parameter for indicating a second feedback interval, where the second feedback interval is an interval between the feedback subframe and a subframe that transmits the D2D data packet, the second feedback interval is a fixed time domain interval or a minimum time domain interval, and the retransmission module 620 determines the position of the feedback subframe according to the indication in the control signaling.

When the second feedback interval is the minimum time domain interval, the retransmission module 620 determines the second available feedback subframe satisfying the minimum time domain interval as the feedback subframe for receiving the feedback information.

In a preferred embodiment, the retransmission module 620 retransmits the D2D packet to the first UE by:

in a first mode, the retransmission module 620 determines a resource for retransmission of a D2D data packet according to a control signaling sent by a network side device, and retransmits the D2D data packet in the resource for retransmission of the D2D data packet;

second, the retransmission module 620 determines resources for retransmission of D2D data packets, sends control signaling for scheduling retransmission of the D2D data packets to the first UE, and retransmits the D2D data packets in the resources for retransmission of D2D data packets.

Specifically, the retransmission module 620 sends control signaling for scheduling retransmission of the D2D data packet to the first UE on the resources for scheduling SA retransmission allocated by D2D, and the retransmission module 620 retransmits the D2D data packet on the retransmission resources indicated by the control signaling. The control signaling includes part or all of the following parameters for indicating retransmission of the D2D data packet: HARQ process number, new data indication NDI, redundancy version RV, time domain and/or frequency domain resource allocation parameters of data retransmission.

In a third mode, the retransmission module 620 retransmits the D2D data packet in the same HARQ process, where the subframe corresponding to the same HARQ process is a subframe corresponding to an HARQ process of cellular communication uplink transmission or a subframe corresponding to an HARQ process of D2D communication;

in a fourth mode, the retransmission module 620 determines the retransmission position of the D2D data according to the position of the feedback subframe and a fourth preset interval, where the fourth preset interval is an interval between the feedback subframe and the retransmission subframe of the D2D data packet, the fourth preset interval is a fixed time domain interval, and the retransmission module retransmits the D2D data packet at the retransmission position of the D2D data.

In a preferred embodiment, the transmitting module 610 transmits the D2D data packet to the first UE, including: the transmission module 610 transmits a D2D data packet in a subframe indicated by a bitmap; the retransmission module 620 retransmitting the D2D data packet to the first UE, including the retransmission module 620 retransmitting the D2D data packet at a subframe indicated by the bitmap; each bit in the bitmap corresponds to one HARQ process.

It will be apparent to those skilled in the art that the modules or steps of the present invention described above may be implemented by a general purpose computing device, they may be centralized on a single computing device or distributed across a network of multiple computing devices, and alternatively, they may be implemented by program code executable by a computing device, such that they may be stored in a storage device and executed by a computing device, and in some cases, the steps shown or described may be performed in an order different than that described herein, or they may be separately fabricated into individual integrated circuit modules, or multiple ones of them may be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. 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.

Claims

1. A device-to-device D2D packet receiving method, comprising:

2. The method of claim 1,

and the subframe for sending the feedback information is a feedback subframe, and the first UE determines the position of the feedback subframe according to a preset rule or determines the position of the feedback subframe according to an indication in a control signaling.

3. The method of claim 2,

the first UE determines the position of the feedback subframe according to a preset rule, and the method comprises the following steps:

the preset rule is that a first preset interval is arranged between the feedback subframe and a subframe for receiving the D2D data packet, the first preset interval is a fixed time domain interval or a minimum time domain interval, and the first UE determines the position of the feedback subframe according to the position of the subframe for receiving the D2D data packet and the first preset interval.

4. The method of claim 3,

when the first UE determines the feedback subframe position according to the subframe position of the received D2D data packet and the first preset interval, the method further includes:

when there is a D2D data reception need in the determined feedback subframe, the first UE relinquishing D2D data reception; when there is a D2D data transmission need in the determined feedback subframe and the target UE for the D2D data transmission is not the second UE, the first UE relinquishes D2D data transmission; when there is a requirement for transmitting D2D data in the determined feedback subframe and the target UE for transmitting the D2D data is the second UE, the first UE transmits the feedback information in the feedback subframe after multiplexing the feedback information with the D2D data.

5. The method of claim 2,

the first UE determines the position of the feedback subframe according to the indication in the control signaling, and the method comprises the following steps:

the indication in the control signaling comprises a parameter for indicating a position of a feedback subframe or a parameter for indicating a first feedback interval, wherein the first feedback interval is an interval between the feedback subframe and a subframe for receiving the D2D data packet, the first feedback interval is a fixed time domain interval or a minimum time domain interval, and the first UE determines the position of the feedback subframe according to the indication in the control signaling.

6. The method according to claim 3 or 5,

the first UE determines the position of the feedback subframe according to the minimum time domain interval, and the method comprises the following steps:

determining a first available feedback subframe satisfying the minimum time domain interval as a feedback subframe for sending feedback information, wherein the first available feedback subframe refers to a subframe satisfying at least one of the following conditions: a subframe configured with feedback information transmission resources or indicated as a feedback information transmission subframe, a cellular communication data reception or transmission subframe other than the first UE, a D2D data reception or transmission subframe other than the first UE, a random access subframe other than the first UE.

7. The method according to any one of claims 1 to 5,

the first UE receiving the retransmission of the D2D data packet, comprising:

the first UE receives retransmission of the D2D data packet according to scheduling of network side equipment or second UE; or,

the first UE receives the retransmission of the D2D data packet in the same hybrid automatic repeat request (HARQ) process; or,

the first UE determines the retransmission position of the D2D data according to the position of the feedback subframe and a second preset interval, wherein the second preset interval is the interval between the feedback subframe and the retransmission subframe of the D2D data packet, the second preset interval is a fixed time domain interval, and the first UE receives the retransmission of the D2D data packet at the retransmission position of the D2D data.

8. The method of claim 7,

the first UE receives the retransmission of the D2D data packet according to the scheduling of the network side device or the second UE, including:

the first UE receives a control signaling sent by a network side device or a control signaling sent by a resource used for scheduling and allocating SA retransmission by a second UE at D2D, the control signaling is used for scheduling retransmission of the D2D data packet, and the first UE receives the retransmission of the D2D data packet according to the indication of the control signaling.

9. The method of claim 8,

the control signaling includes part or all of the following parameters for indicating retransmission of the D2D data packet: HARQ process number, new data indication NDI, redundancy version RV, time domain and/or frequency domain resource allocation parameters of data retransmission.

10. The method of claim 7,

the first UE receiving a retransmission of a D2D data packet in the same HARQ process, including:

and the first UE receives the retransmission of the D2D data in a subframe corresponding to the same HARQ process, wherein the subframe corresponding to the same HARQ process is a subframe corresponding to an HARQ process of cellular communication uplink transmission or a subframe corresponding to an HARQ process of D2D communication.

11. The method of claim 1,

the first UE receives a D2D data packet sent by a second UE, and the data packet comprises: the first UE receiving a D2D data packet at a subframe indicated by a bitmap;

the first UE receiving the retransmission of the D2D data packet, comprising: the first UE receiving a retransmission of the D2D data packet at a subframe indicated by the bitmap;

each bit in the bitmap corresponds to one HARQ process.

12. A device-to-device D2D packet transmitting method, comprising:

the second UE transmitting a D2D data packet to the first UE;

13. The method of claim 12,

the subframe of the first UE for sending the feedback information is a feedback subframe, the second UE determines the position of the feedback subframe according to a preset rule or determines the position of the feedback subframe according to an indication in a control signaling, and the feedback information is received in the feedback subframe.

14. The method of claim 13,

the second UE determines the position of the feedback subframe according to a preset rule, including:

the preset rule is that a third preset interval is arranged between the feedback subframe and the subframe for sending the D2D data packet, the third preset interval is a fixed time domain interval or a minimum time domain interval, and the second UE determines the position of the feedback subframe according to the position of the subframe for sending the D2D data packet and the third preset interval.

15. The method of claim 13,

the second UE determining the position of the feedback subframe according to an indication in a control signaling, including:

the indication in the control signaling comprises a parameter for indicating the position of the feedback subframe or a parameter for indicating a second feedback interval, where the second feedback interval is an interval between the feedback subframe and a subframe for sending a D2D data packet, the second feedback interval is a fixed time domain interval or a minimum time domain interval, and the second UE determines the position of the feedback subframe according to the indication in the control signaling.

16. The method according to claim 14 or 15,

the second UE determining the position of the feedback subframe according to the minimum time domain interval, including: determining a second available feedback subframe satisfying the minimum time domain interval as a feedback subframe for receiving feedback information, wherein the second available feedback subframe refers to a subframe satisfying at least one of the following conditions: and configuring feedback information transmission resources, wherein the subframes are not D2D data receiving or transmitting subframes of the second UE and are not random access subframes of the second UE.

17. The method according to any one of claims 12 to 15,

the retransmitting the D2D data packet to the first UE includes:

the second UE determines resources for D2D data packet retransmission according to control signaling sent by the network side equipment, and retransmits the D2D data packet in the resources for D2D data packet retransmission; or,

the second UE determines resources for D2D data packet retransmission, sends control signaling to the first UE for scheduling the D2D data packet retransmission, retransmits the D2D data packet in the resources for D2D data packet retransmission.

18. The method according to any one of claims 12 to 15,

the retransmitting the D2D data packet to the first UE includes:

the second UE retransmits the D2D data packet in the same hybrid automatic repeat request (HARQ) process, wherein the subframe corresponding to the same HARQ process is a subframe corresponding to an HARQ process of cellular communication uplink transmission or a subframe corresponding to an HARQ process of D2D communication; or

The second UE determines a retransmission position of the D2D data according to a position of a feedback subframe and a fourth preset interval, wherein the fourth preset interval is an interval between the feedback subframe and a retransmission subframe of the D2D data packet, the fourth preset interval is a fixed time domain interval, and the second UE retransmits the D2D data packet at the retransmission position of the D2D data.

19. The method of claim 17,

the second UE determining resources for D2D data packet retransmission, sending control signaling to the first UE for scheduling the D2D data packet retransmission, retransmitting the D2D data packet in the resources for D2D data packet retransmission, comprising:

the second UE sends control signaling for scheduling D2D data packet retransmission to the first UE on resources for D2D scheduling assignment SA retransmission, and the second UE retransmits the D2D data packet on retransmission resources indicated by the control signaling.

20. The method of claim 17,

21. The method of claim 12,

the second UE transmitting a D2D data packet to the first UE, comprising: the second UE sends a D2D data packet in a subframe indicated by the bitmap;

the second UE retransmitting the D2D data packet to the first UE, comprising: the second UE retransmits the D2D data packet in the subframe indicated by the bitmap;

each bit in the bitmap corresponds to one HARQ process.

22. A device-to-device D2D communication scheduling method, comprising:

23. The method of claim 22,

receiving feedback information sent by the first UE and used for indicating the D2D data packet verification result, including:

the network side equipment determines that a subframe having a fifth preset interval with a subframe for sending a D2D data packet is a feedback subframe for sending feedback information by a first UE, where the fifth preset interval is a fixed time domain interval or a minimum time domain interval, and the network side equipment receives the feedback information sent by the first UE in the feedback subframe.

24. The method of claim 23,

the method for determining, by the network side device, that a subframe having a fifth preset interval with a subframe for sending a D2D data packet is a feedback subframe for sending feedback information by the first UE includes:

the network side equipment determines a subframe which is separated from a subframe of a D2D data packet sent by the first UE by a fixed time interval as a feedback subframe for receiving feedback information; or,

the network side device determines a third available feedback subframe, where an interval between the third available feedback subframe and a subframe where the first UE sends a D2D data packet satisfies a minimum time domain interval, as a feedback subframe for receiving feedback information, where the third available feedback subframe refers to a subframe that satisfies at least one of the following conditions: and configuring feedback information transmission resources, wherein the subframes are not D2D data receiving or transmitting subframes of the first UE, are not D2D data receiving or transmitting subframes of the second UE, and are not random access subframes.

25. The method of claim 22,

if the feedback information is a NACK, the method further comprises: the network side equipment sends a control signaling to the first UE, wherein the control signaling is used for scheduling the first UE to receive retransmission of the D2D data packet;

26. A device-to-device D2D data packet receiving apparatus, comprising a first D2D data packet receiving module, a verification module, a first sending module and a second D2D data packet receiving module, wherein:

the verification module is used for verifying the D2D data packet;

27. The apparatus of claim 26,

the first sending module is further configured to determine a position of the feedback subframe according to a preset rule or determine a position of the feedback subframe according to an indication in a control signaling.

28. The apparatus of claim 27,

the first sending module determines the position of the feedback subframe according to a preset rule, and the method comprises the following steps:

the preset rule is that a first preset interval is arranged between the feedback subframe and a subframe for receiving the D2D data packet, the first preset interval is a fixed time domain interval or a minimum time domain interval, and the first sending module determines the position of the feedback subframe according to the position of the subframe for receiving the D2D data packet and the first preset interval.

29. The apparatus of claim 28,

the apparatus further comprises a determining module, configured to, after the first sending module determines a feedback subframe position according to a subframe position where the D2D data packet is received and the first preset interval, determine that if there is a D2D data reception requirement in the determined feedback subframe, notify the first D2D data packet receiving module and the second D2D data packet receiving module to drop D2D data reception; judging whether the determined feedback subframe has a D2D data transmission requirement and the target UE of the D2D data transmission is not the second UE, and informing the first transmission module to abandon the D2D data transmission; and if the determined feedback subframe has a D2D data transmission requirement and the target UE for D2D data transmission is the second UE, informing the first transmission module to multiplex the feedback information with the D2D data and then transmitting the multiplexed feedback information in the feedback subframe.

30. The apparatus of claim 27,

the first sending module determines the position of the feedback subframe according to an indication in a control signaling, and the determining includes:

the indication in the control signaling comprises a parameter for indicating a position of a feedback subframe or a parameter for indicating a first feedback interval, the first feedback interval is an interval between the feedback subframe and a subframe for receiving the D2D data packet, the first feedback interval is a fixed time domain interval or a minimum time domain interval, and the first sending module determines the position of the feedback subframe according to the indication in the control signaling.

31. The apparatus of claim 28 or 30,

the first transceiver module determines the position of the feedback subframe according to the minimum time domain interval, including:

the first transceiver module determines a first available feedback subframe meeting the minimum time domain interval as a feedback subframe for sending feedback information, where the first available feedback subframe is a subframe meeting at least one of the following conditions: a subframe configured with feedback information transmission resources or indicated as a feedback information transmission subframe, a cellular communication data reception or transmission subframe other than the first UE, a D2D data reception or transmission subframe other than the first UE, a random access subframe other than the first UE.

32. The apparatus of any one of claims 26-30,

the second D2D data packet receiving module receiving a retransmission of the D2D data packet, including:

the second D2D data packet receiving module receives the retransmission of the D2D data packet according to the scheduling of the network side equipment or the second UE; or,

the second D2D data packet receiving module receives the retransmission of the D2D data packet in the same HARQ process; or,

the second D2D data packet receiving module determines a retransmission position of the D2D data according to the position of the feedback subframe and a second preset interval, where the second preset interval is an interval between the feedback subframe and a retransmission subframe of the D2D data packet, the second preset interval is a fixed time domain interval, and the second D2D data packet receiving module receives a retransmission of the D2D data packet at the retransmission position of the D2D data.

33. The apparatus of claim 32,

the second D2D data packet receiving module receives the retransmission of the D2D data packet according to the scheduling of the network side device or the second UE, including:

the second D2D data packet receiving module receives a control signaling sent by a network side device or a control signaling sent by a second UE on a resource for D2D SA retransmission, where the control signaling is used to schedule retransmission of the D2D data packet, and the second D2D data packet receiving module receives retransmission of the D2D data packet according to an indication of the control signaling.

34. The apparatus of claim 33,

35. The apparatus of claim 32,

the second D2D data packet receiving module receives the retransmission of the D2D data packet in the same HARQ process, including:

the second D2D data packet receiving module receives the retransmission of the D2D data in a subframe corresponding to the same HARQ process, where the subframe corresponding to the same HARQ process is a subframe corresponding to an HARQ process of cellular communication uplink transmission or a subframe corresponding to an HARQ process of D2D communication.

36. The method of claim 26,

the first D2D data packet receiving module receives D2D data packets sent by a second UE, and comprises: the first D2D data packet receiving module receives D2D data packets in the sub-frame indicated by the bitmap;

the second D2D data packet receiving module receiving a retransmission of the D2D data packet, including: the second D2D data packet receiving module receives a retransmission of the D2D data packet at a subframe indicated by the bitmap;

each bit in the bitmap corresponds to one HARQ process.

37. A device-to-device D2D data packet transmission apparatus, comprising a transmission module and a retransmission module, wherein:

38. The apparatus of claim 37,

the subframe in which the first UE sends the feedback information is a feedback subframe, the retransmission module determines the position of the feedback subframe according to a preset rule or determines the position of the feedback subframe according to an indication in a control signaling, and the feedback information is received in the feedback subframe.

39. The apparatus of claim 38,

the retransmission module determines the position of the feedback subframe according to a preset rule, and the determination comprises the following steps:

the preset rule is that a third preset interval is arranged between the feedback subframe and the subframe for sending the D2D data packet, the third preset interval is a fixed time domain interval or a minimum time domain interval, and the retransmission module determines the position of the feedback subframe according to the position of the subframe for sending the D2D data packet and the third preset interval.

40. The apparatus of claim 38,

the retransmission module determines the position of the feedback subframe according to the indication in the control signaling, and the method comprises the following steps:

the indication in the control signaling comprises a parameter for indicating the position of the feedback subframe or a parameter for indicating a second feedback interval, where the second feedback interval is an interval between the feedback subframe and a subframe for sending the D2D data packet, the second feedback interval is a fixed time domain interval or a minimum time domain interval, and the retransmission module determines the position of the feedback subframe according to the indication in the control signaling.

41. The apparatus of claim 39 or 40,

the retransmission module determines the position of the feedback subframe according to the minimum time domain interval, including: determining a second available feedback subframe satisfying the minimum time domain interval as a feedback subframe for receiving feedback information, wherein the second available feedback subframe refers to a subframe satisfying at least one of the following conditions: and configuring feedback information transmission resources, wherein the subframes are not D2D data receiving or transmitting subframes of the second UE and are not random access subframes of the second UE.

42. The apparatus of any one of claims 37-40,

the retransmission module retransmits the D2D data packet to the first UE, including:

the retransmission module determines a resource for retransmitting a D2D data packet according to a control signaling sent by a network side device, and retransmits the D2D data packet in the resource for retransmitting the D2D data packet; or,

the retransmission module determines resources for D2D data packet retransmission, sends control signaling to the first UE for scheduling the D2D data packet retransmission, and retransmits the D2D data packet in the resources for D2D data packet retransmission.

43. The apparatus of any one of claims 37-40,

the retransmission module retransmits the D2D data packet in the same hybrid automatic repeat request (HARQ) process, wherein the subframe corresponding to the same HARQ process is a subframe corresponding to an uplink transmission HARQ process of cellular communication or a subframe corresponding to an HARQ process of D2D communication; or

The retransmission module determines a retransmission position of the D2D data according to a position of a feedback subframe and a fourth preset interval, where the fourth preset interval is an interval between the feedback subframe and a retransmission subframe of the D2D data packet, the fourth preset interval is a fixed time domain interval, and the retransmission module retransmits the D2D data packet at the retransmission position of the D2D data.

44. The apparatus of claim 42,

the retransmission module determines resources for D2D data packet retransmission, sends control signaling to the first UE for scheduling the D2D data packet retransmission, retransmits the D2D data packet in the resources for D2D data packet retransmission, including:

the retransmission module sends control signaling for scheduling retransmission of the D2D data packet to the first UE on resources for D2D scheduling assignment of SA retransmission, and the retransmission module retransmits the D2D data packet on retransmission resources indicated by the control signaling.

45. The apparatus of claim 42,

46. The apparatus of claim 37,

the transmission module transmits a D2D data packet to the first UE, including: the transmission module sends a D2D data packet in a subframe indicated by a bitmap;

the retransmission module retransmitting the D2D data packet to the first UE, including the retransmission module retransmitting the D2D data packet at a subframe indicated by the bitmap;

each bit in the bitmap corresponds to one HARQ process.

47. A device-to-device D2D communication scheduling apparatus, comprising a first scheduling module, a feedback information receiving module, and a second scheduling module, wherein:

48. The apparatus of claim 47,

the feedback information receiving module receives feedback information sent by the first UE and used for representing the D2D data packet verification result, and includes:

the feedback information receiving module determines that a subframe having a fifth preset interval with a subframe for transmitting a D2D data packet is a feedback subframe for transmitting feedback information by a first UE, where the fifth preset interval is a fixed time domain interval or a minimum time domain interval, and the feedback information receiving module receives the feedback information transmitted by the first UE at the feedback subframe.

49. The apparatus of claim 48,

the feedback information receiving module determines that a subframe having a fifth preset interval with a subframe for transmitting the D2D data packet is a feedback subframe for transmitting feedback information by the first UE, and includes:

the feedback information receiving module determines a subframe separated from a subframe of a D2D data packet sent by the first UE by a fixed time interval as a feedback subframe for receiving feedback information; or,

the feedback information receiving module determines a third available feedback subframe, which satisfies a minimum time domain interval with an interval of a subframe in which the first UE transmits the D2D data packet, as a feedback subframe for receiving feedback information, where the third available feedback subframe is a subframe satisfying at least one of the following conditions: and configuring feedback information transmission resources, wherein the subframes are not D2D data receiving or transmitting subframes of the first UE, are not D2D data receiving or transmitting subframes of the second UE, and are not random access subframes.

50. The apparatus of claim 47,

when the feedback information is NACK, the second scheduling module is further configured to send a control signaling to the first UE, where the control signaling is used to schedule the first UE to receive retransmission of a D2D data packet;