TW201424442A - Method of transmitting signaling of device-to-device communication in cellular network - Google Patents

Abstract

The invention provides a method of transmitting signaling of device-to-device communication in a cellular network. Particularly the invention provides a method of transmitting an HARQ of device-to-device communication in a cellular network. With the HARQ transmission solution of the invention, HARQ transmission can be performed effectively while maintaining backward compatibility.

Description

Signal transmission method for device-to-device communication under cellular network

The present application relates to communication systems, and more particularly to device-to-device communication in a cellular network.

In recent years, a device-to-device (D2D) communication mode has been proposed. The device-to-device communication mode is a short-range service that is different from the traditional cellular communication mode. For traditional cellular communication systems, even if the distance between user equipments is very close, communication between them should be handled by the RAN and core network nodes (including base stations, etc.). For the above application scenarios (that is, the distance between communication participants is very close), in order to save cellular resources and reduce communication delay, a cellular controlled D2D communication system is introduced as a potential short-distance technology of LTE-A. Currently, 3GPP has launched a new research project to develop standards for D2D technology for proximity services.

For traditional cellular communication systems, communication between user equipment of the same cell should be scheduled and transmitted/received by the base station. In D2D communication, two user devices can communicate directly. Obviously, the existing HARQ transmission mechanism does not properly support D2D communication. Therefore, there is It is necessary to provide an efficient HARQ mechanism for D2D communication under a cellular infrastructure while maintaining backward compatibility.

In the traditional cellular communication, if the user equipment A wants to send data to the user equipment B, then first, the user equipment A sends data to the base station in the uplink, and then the base station forwards the data to the user equipment B in the downlink. Therefore, there will be two separate HARQ processes in the uplink and downlink respectively.

The steps of the traditional HARQ mechanism in cellular communication are as follows:

Uplink HARQ transmission

Step 1: User equipment A sends a scheduling request to the base station.

Step 2: The base station sends a PDCCH (physical downlink control channel) to the user equipment A in the (n1)th subframe.

Step 3: User equipment A transmits data to the base station on the allocated frequency resource in the (n1+k1)th subframe.

Step 4: For non-adaptive HARQ, the base station transmits a HARQ ACK/NACK to the user equipment A on the PHICH (Entity HARQ Indication Channel) at the (n1+k1+k2) subframes; for the adaptive HARQ, the base station The (n1+k1+k2) subframes send a HARQ ACK/NACK to the user equipment A on the PDCCH.

Step 5: User equipment A receives the HARQ ACK/NACK on the PHICH or PDCCH. If user equipment A receives a NACK on the PDCCH, user equipment A is in the (n1+k1+k2+k3) subframes. The data is retransmitted to the base station on the newly allocated frequency resource; if the user equipment A receives the NACK on the PHICH, the user equipment retransmits on the (n1+k1+k2+k3) subframes on the original frequency resource. This data is sent to the base station.

Step 6: Repeat steps 4 through 5 above until the base station correctly decodes the data.

Downstream HARQ transmission

Step 1: The base station forwards data to the user equipment B in the (n2)th subframe.

Step 2: If the user equipment B has data to transmit on the PUSCH (Physical Uplink Shared Channel), the user equipment B sends a HARQ ACK/NACK to the base station on the PUSCH in the (n2+k4)th subframe; if the user equipment B has no data to transmit on the PUSCH, then user equipment B transmits a HARQ ACK/NACK to the base station on the PUCCH (Physical Uplink Control Channel) in the (n2+k4)th subframe.

Step 3: The base station receives the HARQ ACK/NACK. If the HARQ feedback is NACK, the base station retransmits the data to the user equipment B in the (n2+k4+k5) subframes.

Step 4: Repeat steps 2 through 3 above until User Equipment B correctly decodes the data.

In traditional cellular communication, HARQ feedback is designed to be only between the user equipment and the base station. In D2D communication, since user equipment A can directly communicate with user equipment B, the main challenge is On: How to use the existing data channel or control channel to feed back HARQ ACK/NACK between user equipments A and B, and at the same time have less impact on the existing HARQ mechanism in cellular communication.

Based on the above considerations, the present invention proposes a HARQ transmission method and other signal transmission methods suitable for D2D communication under a cellular network.

According to an embodiment of an aspect of the present invention, a HARQ transmission method for device-to-device communication under a cellular network is proposed, wherein the cellular network includes a base station and device-to-device communication a first user equipment and a second user equipment, the method comprising the steps of: a. Transmitting, by the first user equipment, data on the allocated resource to the second user equipment; b. Receiving, by the first user equipment, HARQ feedback forwarded by the base station on a PDCCH or a PHICH; c. If the HARQ feedback is a NACK signal and the NACK signal is received on the PDCCH, the data is retransmitted by the first user equipment on the newly allocated resource; if the HARQ feedback is a NACK signal and is in the PHICH Upon receiving the NACK signal, the first user equipment retransmits the data on the originally allocated resource.

Advantageously, the step b further comprises: receiving, by the first user equipment, a device-to-device communication indication message provided by the base station, wherein the device-to-device communication indication message is used to indicate that the HARQ feedback is For device-to-device communication.

According to another embodiment of the present invention, a HARQ transmission method for device-to-device communication under a cellular network is proposed, wherein the cellular network includes a base station and a first device-to-device communication User equipment and second user equipment, the method comprising the following steps: A. Receiving data from the first user equipment by the second user equipment and decoding the data; B. If the second user equipment currently has data to transmit on the PUSCH, the second user equipment sends HARQ feedback to the base station on the PUSCH; if the second user equipment does not currently have data, it needs to be on the PUSCH. The second user equipment sends HARQ feedback to the base station on the PUCCH.

Advantageously, the step B further comprises: providing, by the second user equipment, a device-to-device communication indication message to the base station, the device-to-device communication indication message being used to indicate that the HARQ feedback is for a device-to-device Communication.

According to still another embodiment of the present invention, a HARQ transmission method for device-to-device communication under a cellular network is proposed, wherein the cellular network includes a base station and a device-to-device communication first User equipment and second user equipment, the method comprising the steps of: i. Receiving, by the base station, HARQ feedback from the second user equipment; ii. If the HARQ feedback is a NACK signal and corresponds to an adaptive HARQ, the base station transmits the HARQ feedback to the first user equipment on the PDCCH; if the HARQ feedback is a NACK signal and corresponds to a non-self Adapting to HARQ and semi-static HARQ, the base station forwards the HARQ feedback to the first user equipment on the PHICH; iii. If the HARQ feedback is an ACK signal, the base station forwards the HARQ feedback to the first user setting on the PHICH. Ready.

Advantageously, the step i further comprises: receiving, by the base station, a device-to-device communication indication message provided by the second user equipment; the step ii further comprising: providing, by the base station, a device-to-device communication indication Sending a message to the first user equipment; the step iii further includes: providing, by the base station, a device-to-device communication indication message to the first user equipment; wherein the device-to-device communication indication message is used to indicate The HARQ feedback is for device-to-device communication.

According to still another embodiment of the present invention, a HARQ transmission method for device-to-device communication under a cellular network is proposed, wherein the cellular network includes a base station and a device-to-device communication first User equipment and second user equipment, the method comprising the following steps: I. Transmitting, by the first user equipment, data on the allocated resource to the second user equipment; II. Receiving, by the first user equipment, HARQ feedback from the second user equipment on a PUSCH or a PDCCH; III. If the HARQ feedback is a NACK signal, the data is retransmitted by the first user equipment on the originally allocated resource; IV. If the HARQ feedback is an ACK signal, the first user equipment notifies the base station to release the allocated resources.

Advantageously, the step II further comprises: receiving, by the first user equipment, a device-to-device communication indication message provided by the second user equipment, wherein the device-to-device communication indication message is used to indicate the HARQ Feedback is for device-to-device communication.

According to still another embodiment of the present invention, a honeycomb type is proposed A HARQ transmission method for device-to-device communication under a network, wherein the cellular network includes a base station and a first user equipment and a second user equipment based on device-to-device communication, and the method includes the following steps: m . Receiving data from the first user equipment by the second user equipment and decoding the data; n. If the second user equipment currently has data to transmit on the PUSCH, the second user equipment sends HARQ feedback to the first user equipment on the PUSCH; if the second user equipment does not currently have data, The PUSCH transmits on the PUSCH, and the second user equipment sends HARQ feedback to the first user equipment on the PUCCH.

Advantageously, the step n further comprises: providing, by the second user equipment, a device-to-device communication indication message to the first user equipment, the device-to-device communication indication message being used to indicate that the HARQ feedback is for a device To the device communication.

According to still another embodiment of the present invention, a HARQ transmission method for device-to-device communication under a cellular network is proposed, wherein the cellular network includes a base station and a device-to-device communication first User equipment and second user equipment, the method comprising the steps of: x. Transmitting, by the first user equipment, data on the allocated resource to the second user equipment; y. Receiving, by the first user equipment, HARQ feedback from the second user equipment; z. If the HARQ feedback is a NACK signal and the first user equipment acquires a newly allocated resource from the base station, the data is retransmitted by the first user equipment on the newly allocated resource; The HARQ feedback is a NACK signal and If the first user equipment does not acquire the newly allocated resources from the base station, the first user equipment retransmits the data on the originally allocated resources.

Advantageously, the step y further comprises: receiving, by the first user equipment, a device-to-device communication indication message provided by the second user equipment, wherein the device-to-device communication indication message is used to indicate the HARQ Feedback is for device-to-device communication.

According to still another embodiment of the present invention, a HARQ transmission method for device-to-device communication under a cellular network is proposed, wherein the cellular network includes a base station and a device-to-device communication first User equipment and second user equipment, the method comprising the steps of: M. Receiving data from the first user equipment by the second user equipment and decoding the data; N. If the second user equipment currently has data to transmit on the PUSCH, the second user equipment sends HARQ feedback to the base station and the first user equipment on the PUSCH; if the second user equipment If no data needs to be transmitted on the PUSCH, the second user equipment sends HARQ feedback to the base station and the first user equipment on the PUCCH.

Advantageously, the step N further comprises: providing, by the second user equipment, a device-to-device communication indication message to the base station and the first user equipment, the device-to-device communication indication message being used to indicate the HARQ feedback is for device-to-device communication.

According to still another embodiment of the present invention, a HARQ transmission method for device-to-device communication under a cellular network is proposed, wherein the cellular network includes a base station and a device-to-device communication first User equipment and second user equipment, the method comprising the steps of: X. Receiving, by the base station, HARQ feedback from the second user equipment; Y. If the HARQ feedback is a NACK signal and corresponds to an adaptive HARQ, the base station provides the newly allocated resource to the first user equipment; if the HARQ feedback is a NACK signal and corresponds to a non-adaptive HARQ and Semi-static HARQ, the base station does not provide newly allocated resources to the first user equipment.

Advantageously, the step X further comprises: receiving, by the base station, a device-to-device communication indication message provided by the second user equipment, wherein the device-to-device communication indication message is used to indicate that the HARQ feedback is For device-to-device communication.

According to another aspect of the present invention, a signal transmission method for device-to-device communication under a cellular network is provided, wherein the cellular network includes a base station and a first user based on device-to-device communication The device and the second user equipment, the method includes the following steps: sending, by the second user equipment, a signal to the base station; wherein the signal includes any one of the following: CQI, CSI, PMI, rank indication, buffer status Report and RRC signal.

The various aspects of the invention will be apparent from the following description of the specific embodiments.

10‧‧‧First User Equipment

20‧‧‧Second user equipment

30‧‧‧Base station

40‧‧‧ Third User Equipment

50‧‧‧Fourth User Equipment

The above and other features of the present invention will be more apparent from the detailed description of the non-limiting embodiments illustrated herein 1 shows a network topology diagram of D2D communication under a cellular network according to an embodiment of the present invention; FIG. 2 shows a flow chart of a HARQ transmission method according to an embodiment of the present invention; A flow chart of a HARQ transmission method according to another embodiment of the present invention; and FIG. 4 shows a flow chart of a HARQ transmission method according to still another embodiment of the present invention. The same or similar reference numerals in the drawings denote the same or similar parts.

The embodiments of the invention are described in detail below with reference to the accompanying drawings.

For D2D communication under the cellular network, in order to achieve correct communication between user equipments, an additional indication message needs to be defined to indicate whether the current HARQ transmission is for device-to-device communication or for cellular communication. It can be implemented in two ways:

(1) The reserved bit bits in the existing PDCCH, PUCCH, PHICH, and PUSCH are used as the indication bit. For example, one bit can be used to indicate whether the current HARQ transmission is a HARQ transmission for device-to-device communication or a HARQ transmission for cellular communication.

(2) Distinguish by subframe/frequency/antenna port/sequence. For example, sub-frame 1 can be defined for device-to-device HARQ transmission, while other sub-frames are used for HARQ transmission of cellular communication. Another example is that Some dedicated frequency resources are used for device-to-device HARQ transmission, while other frequency resources are used for HARQ transmission of cellular communication. As another example, HARQ transmissions for cellular communication or HARQ transmissions for cellular communication can be distinguished by different sequence offsets.

The following uses the reserved bit bits in the existing PDCCH, PUCCH, PHICH, and PUSCH to indicate whether the current HARQ transmission is a device-to-device HARQ transmission or a cellular communication HARQ transmission, and is combined with the network topology diagram of FIG. Various embodiments of the invention are described.

The network topology of FIG. 1 includes a base station 30, first user equipment 10 and second user equipment 20 based on D2D communication, and third user equipment 40 and fourth user equipment 50 based on cellular communication.

Example 1

In this embodiment, the HARQ feedback passes through two steps: the second user equipment 20 to the base station 30 and the base station 30 to the first user equipment 10.

Referring to FIG. 2, in step S21, the first user equipment 10 transmits a scheduling request to the base station 30.

After the base station 30 receives the scheduling request from the first user equipment 10, in step S22, the base station 30 transmits a PDCCH to the first user equipment 10 and the second user equipment 20 in the (n1)th subframe for indicating Resources allocated for the first user device 10.

In step S23, the first user equipment 10 transmits data to the second user equipment 20 on the allocated resources in the (n1+k1)th subframe.

The second user equipment 20 receives the number from the first user equipment 10 Thereafter, in step S24, the second user equipment 20 decodes the data and transmits HARQ feedback and provides a device-to-device communication indication message to the base station 30 in the (n1+k1+k2) subframes. Specifically, if the second user equipment 20 currently has data to transmit on the PUSCH, the second user equipment 20 sends HARQ feedback to the base station 30 on the PUSCH and sets an indication bit bit in the PUSCH (for example, the indication is The bit is set to 0) to indicate that the HARQ feedback is for device-to-device communication; if the second user equipment 20 does not currently have data to transmit on the PUSCH, the second user equipment 20 sends HARQ feedback to the base station on the PUCCH 30 and setting the indication bit bit in the PUCCH (eg, setting the indication bit to 0) to indicate that the HARQ feedback is for device-to-device communication.

After the base station 30 receives the HARQ feedback and the device-to-device indication message from the second user equipment 20, in step S25, if the HARQ feedback is a NACK signal and corresponds to the adaptive HARQ, the base station 30 is at the (n1+k1) +k2+k3) sub-frames forward the HARQ feedback to the first user equipment 10 on the PDCCH and set the indication bit bits in the PUCCH (eg, set the indication bit to 0) to indicate that the HARQ feedback is for the device If the HARQ feedback is a NACK signal and corresponds to the non-adaptive HARQ and the semi-static HARQ, the base station 30 forwards the HARQ feedback to the first (n1+k1+k2+k3) subframes on the PHICH. A user equipment 10 and setting an indication bit bit in the PHICH (for example, setting the indication bit to 0) to indicate that the HARQ feedback is for device-to-device communication; if the HARQ feedback is an ACK signal, the base station 30 Forwarding the HARQ feedback on the PHICH to the first user equipment 10 and setting the indication bit bit in the PHICH (eg, setting the indication bit to 0) to indicate that the HARQ feedback is for device-to-device communication.

After the first user equipment 10 receives the HARQ feedback forwarded by the base station 30 and the device-to-device indication message provided by the base station 30 on the PDCCH or PHICH, in step S26, if the HARQ feedback is a NACK signal and the first user equipment If the NACK signal is received on the PDCCH, the first user equipment 10 retransmits the data on the newly allocated resource indicated in the PDCCH in the (n1+k1+k2++3+k4) subframes; if HARQ If the NACK signal is received and the first user equipment 10 receives the NACK signal on the PHICH, the first user equipment 10 retransmits the (n1+k1+k2++3+k4) subframes on the originally allocated resources. data.

The above steps S24 to S26 are repeated until the second user equipment 20 correctly decodes the data.

In this embodiment, for the link of the second user equipment 20 to the base station 30, the uplink channel PUCCH or PUSCH is used to feed back the HARQ ACK/NACK; for the link from the base station 30 to the first user equipment 10, the link is used. The downlink channel PHICH or PDCCH is used to feed back HARQ ACK/NACK. That is to say, the technical solution of this embodiment reuses the existing control channel or data channel to feed back HARQ ACK/NACK without additional channel overhead.

Example 2

In some application scenarios such as semi-persistent scheduling, the base station will be The HARQ process allocates fixed frequency resources, that is, the base station does not reallocate the scheduled resources in each retransmission. Furthermore, since the architecture of the D2D transmission has not been determined so far, it is also possible for the base station to not control or only partially control the resources for scheduling of the D2D transmission. Based on this, in the present embodiment, a HARQ feedback mechanism directly from the second user equipment 20 to the first user equipment 10 is proposed.

Referring to FIG. 3, in step S31, the first user equipment 10 transmits a scheduling request to the base station 30.

After the base station 30 receives the scheduling request from the first user equipment 10, in step S32, the base station 30 transmits a PDCCH to the first user equipment 10 and the second user equipment 20 in the (n1)th subframe for indicating Resources allocated for the first user device 10.

In step S33, the first user equipment 10 transmits data to the second user equipment 20 on the allocated resources in the (n1+k1)th subframe.

After the second user equipment 20 receives the data from the first user equipment 10, in step S34, the second user equipment 20 decodes the data and sends HARQ feedback in the (n1+k1+k2) subframes. A device-to-device communication indication message is provided to the first user device 10. Specifically, if the second user equipment 20 currently has data to transmit on the PUSCH, the second user equipment 20 sends HARQ feedback to the first user equipment 10 on the PUSCH and sets an indication bit bit in the PUSCH (for example, The indication bit is set to 0) to indicate that the HARQ feedback is for device-to-device communication; if the second user equipment 20 does not currently have data to transmit on the PUSCH, the second user equipment 20 transmits on the PUCCH The HARQ feeds back to the first user equipment 10 and sets an indication bit bit in the PUCCH (eg, sets the indication bit to 0) to indicate that the HARQ feedback is for device-to-device communication.

After the first user equipment 10 receives the HARQ feedback and the device-to-device indication message from the second user equipment 20 on the PUSCH or the PDCCH, in step S35, if the HARQ feedback is a NACK signal, the first user equipment 10 is in the first The (n1+k1+k2+k3) subframes retransmit the data on the originally allocated resources; if the HARQ feedback is an ACK signal, the first user equipment 10 notifies the base station 30 to release the allocated resources.

The above steps S34 to S35 are repeated until the second user equipment 20 correctly decodes the data.

In this embodiment, the HARQ ACK/NACK is directly transmitted from the second user equipment 20 to the first user equipment 10 and the first user equipment 10 does not need to wait for the scheduling message from the base station 30 to perform retransmission, and thus, compared to In the HARQ transmission mechanism in Embodiment 1 above, the HARQ transmission mechanism in this embodiment has less delay. However, the HARQ transmission mechanism in this embodiment has some modifications relative to the HARQ transmission of the existing cellular network. In the cellular communication, the first user equipment receives the HARQ ACK/NACK on the PDCCH or the PHICH, but in this implementation. In the HARQ mechanism of the example, the first user equipment 10 receives the HARQ ACK/NACK on the PUSCH or the PUCCH.

Example 3

In this embodiment, the second user equipment 20 transmits HARQ feedback to the first user equipment 10 and the base station 30 in a broadcast manner.

Referring to FIG. 4, in step S41, the first user equipment 10 transmits a scheduling request to the base station 30.

After the base station 30 receives the scheduling request from the first user equipment 10, in step S42, the base station 30 transmits a PDCCH to the first user equipment 10 and the second user equipment 20 in the (n1)th subframe for indicating Resources allocated for the first user device 10.

In step S43, the first user equipment 10 transmits data to the second user equipment 20 on the allocated resources in the (n1+k1)th subframe.

After the second user equipment 20 receives the data from the first user equipment 10, in step S44, the second user equipment 20 decodes the data and transmits it in the (n1+k1+k2) subframes. The HARQ feeds back and provides device-to-device communication indication messages to the base station 30 and the first user equipment 10. Specifically, if the second user equipment 20 currently has data to transmit on the PUSCH, the second user equipment 20 sends HARQ feedback to the base station 30 and the first user equipment 10 on the PUSCH and sets the indication bit position in the PUSCH. (eg, setting the indicator bit to 0) to indicate that the HARQ feedback is for device-to-device communication; if the second user device 20 does not currently have data to transmit on the PUSCH, then the second user device 20 is on the PUCCH The HARQ feedback is sent to the base station 30 and the first user equipment 10 and the indication bit bits in the PUCCH are set (eg, the indication bit is set to 0) to indicate that the HARQ feedback is for device-to-device communication.

After the base station 30 receives the HARQ feedback and the device-to-device indication message from the second user equipment 20, in step S45, if the HARQ feedback is a NACK signal and corresponds to the adaptive HARQ, the base station 30 is at the (n1+k1) +k2+k3) the subframe transmits a PDCCH to the first user equipment 10 for providing the newly allocated resource to the first user equipment 10; if the HARQ feedback is a NACK signal and corresponds to the non-adaptive HARQ and the semi-static HARQ, The base station 30 does not transmit the PDCCH to the first user equipment 10, that is, does not provide the newly allocated resources to the first user equipment 10.

After the first user equipment 10 receives the HARQ feedback and the device-to-device indication message from the second user equipment 20, in step S46, if the HARQ feedback is a NACK signal and the first user equipment 10 receives the PDCCH from the base station 30 (also That is, the first user equipment 10 acquires the newly allocated resource from the base station 30, and the first user equipment 10 retransmits on the newly allocated resource in the (n1+k1+k2++3+k4) subframes. The data; if the HARQ feedback is a NACK signal and the first user equipment 10 does not receive the PDCCH from the base station 30 (ie, the first user equipment 10 does not acquire the newly allocated resource from the base station 30), the first user equipment 10 retransmits the data on the originally allocated resource in the (n1+k1+k2+k3+k4) subframe.

The above steps S44 to S46 are repeated until the second user equipment 20 correctly decodes the data.

In the present embodiment, the second user equipment 20 broadcasts the HARQ ACK/NACK to the base station 30 and the first user equipment 10, and therefore, the base station 30 does not need to forward the HARQ ACK/NACK to the first user equipment 10. phase Compared with the HARQ transmission mechanism in Embodiment 1 above, this embodiment saves one control channel resource. However, the HARQ transmission mechanism in this embodiment has some modifications relative to the HARQ transmission of the existing cellular network. In the cellular communication, the first user equipment receives the HARQ ACK/NACK on the PDCCH or the PHICH, but in this implementation. In the HARQ mechanism of the example, the first user equipment 10 receives the HARQ ACK/NACK on the PUSCH or the PUCCH.

According to another aspect of the present invention, a signal transmission method for device-to-device communication under a cellular network is also provided. The method includes the following steps: the second user equipment 20 sends a signal to the base station 30; wherein the signal includes any one of the following: CQI, CSI, PMI, rank indication, buffer status report, RRC signal, and the like. Knowing these signal messages by base station 30 is beneficial to enhancing system performance.

It is apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the present embodiments are to be considered as illustrative and not restrictive, and the claims In addition, it is obvious that the word "comprising" does not exclude other elements or steps, and the word "a" or "an" The plurality of elements recited in the claims of the product can also be realized by one element through a software or a hardware. The first, second, etc. words are used to denote names and do not denote any particular order.

Claims (17)

A HARQ transmission method for device-to-device communication under a cellular network, wherein the cellular network includes a base station and a first user equipment and a second user equipment based on device-to-device communication, and the method includes the following Step: a. Transmitting, by the first user equipment, data on the allocated resource to the second user equipment; b. Receiving, by the first user equipment, HARQ feedback forwarded by the base station on a PDCCH or a PHICH; c. If the HARQ feedback is a NACK signal and the NACK signal is received on the PDCCH, the first user equipment retransmits the data on the newly allocated resource; if the HARQ feedback is a NACK signal and the NACK is received on the PHICH The signal is retransmitted by the first user equipment on the originally allocated resource. The method of claim 1, wherein the step b further comprises: receiving, by the first user equipment, a device-to-device communication indication message provided by the base station, wherein the device-to-device communication indication message is The indication that the HARQ feedback is for device-to-device communication. A HARQ transmission method for device-to-device communication under a cellular network, wherein the cellular network includes a base station and a first user equipment and a second user equipment based on device-to-device communication, and the method includes the following Step: A. Receiving data from the first user equipment by the second user equipment and decoding the data; B. If the second user equipment currently has data to transmit on the PUSCH, the second user equipment sends HARQ feedback to the base station on the PUSCH; if the second user equipment does not currently have data to transmit on the PUSCH, The second user equipment sends HARQ feedback to the base station on the PUCCH. The method of claim 3, wherein the step B further comprises: providing, by the second user equipment, a device-to-device communication indication message to the base station, the device-to-device communication indication message indicating the HARQ Feedback is for device-to-device communication. A HARQ transmission method for device-to-device communication under a cellular network, wherein the cellular network includes a base station and a first user equipment and a second user equipment based on device-to-device communication, and the method includes the following Step: i. Receiving, by the base station, HARQ feedback from the second user equipment; ii. If the HARQ feedback is a NACK signal and corresponds to adaptive HARQ, the base station forwards the HARQ feedback to the first user equipment on the PDCCH; if the HARQ feedback is a NACK signal and corresponds to non-adaptive HARQ and semi-static HARQ, the base station forwards the HARQ feedback to the first user equipment on the PHICH; iii. If the HARQ feedback is an ACK signal, the base station forwards the HARQ feedback to the first user equipment on the PHICH. The method of claim 5, wherein the step i further comprises: receiving, by the base station, the second user equipment The device-to-device communication indication message; the step ii further includes: providing, by the base station, a device-to-device communication indication message to the first user equipment; the iii further comprising: providing, by the base station, a device-to-device communication indication message to The first user equipment; wherein the device-to-device communication indication message is used to indicate that the HARQ feedback is for device-to-device communication. A HARQ transmission method for device-to-device communication under a cellular network, wherein the cellular network includes a base station and a first user equipment and a second user equipment based on device-to-device communication, and the method includes the following Step: I. Transmitting, by the first user equipment, data on the allocated resource to the second user equipment; II. Receiving, by the first user equipment, HARQ feedback from the second user equipment on the PUSCH or PDCCH; III. If the HARQ feedback is a NACK signal, the first user equipment retransmits the data on the originally allocated resource; IV. If the HARQ feedback is an ACK signal, the first user equipment notifies the base station to release the allocated resources. The method of claim 7, wherein the step II further comprises: receiving, by the first user equipment, a device-to-device communication indication message provided by the second user equipment, wherein the device-to-device communication indication The message is used to indicate that the HARQ feedback is for device-to-device communication. A HARQ transmission method for device-to-device communication under a cellular network, wherein the cellular network includes a base station and a first user equipment and a second user equipment based on device-to-device communication, and the method includes the following Step: m. Receiving data from the first user equipment by the second user equipment and decoding the data; n. If the second user equipment currently has data to transmit on the PUSCH, the second user equipment sends HARQ feedback to the first user equipment on the PUSCH; if the second user equipment does not currently have data to transmit on the PUSCH, Then, the second user equipment sends HARQ feedback to the first user equipment on the PUCCH. The method of claim 9, wherein the step n further comprises: providing, by the second user equipment, a device-to-device communication indication message to the first user equipment, the device-to-device communication indication message is used to indicate The HARQ feedback is for device-to-device communication. A HARQ transmission method for device-to-device communication under a cellular network, wherein the cellular network includes a base station and a first user equipment and a second user equipment based on device-to-device communication, and the method includes the following Step: x. Transmitting, by the first user equipment, data on the allocated resource to the second user equipment; y. Receiving, by the first user equipment, HARQ feedback from the second user equipment; z. If the HARQ feedback is a NACK signal and the first user sets Receiving the newly allocated resource from the base station, the first user equipment retransmits the data on the newly allocated resource; if the HARQ feedback is a NACK signal and the first user equipment is not obtained from the base station The newly allocated resource is retransmitted by the first user equipment on the originally allocated resource. The method of claim 11, wherein the step y further comprises: receiving, by the first user equipment, a device-to-device communication indication message provided by the second user equipment, wherein the device-to-device communication indication The message is used to indicate that the HARQ feedback is for device-to-device communication. A HARQ transmission method for device-to-device communication under a cellular network, wherein the cellular network includes a base station and a first user equipment and a second user equipment based on device-to-device communication, and the method includes the following Step: M. Receiving data from the first user equipment by the second user equipment and decoding the data; N. If the second user equipment currently has data to transmit on the PUSCH, the second user equipment sends HARQ feedback to the base station and the first user equipment on the PUSCH; if the second user equipment does not currently have data, When the PUSCH is transmitted, the second user equipment sends HARQ feedback to the base station and the first user equipment on the PUCCH. The method of claim 13, wherein the step N further comprises: providing device-to-device communication by the second user equipment Instructing the message to the base station and the first user equipment, the device-to-device communication indication message is used to indicate that the HARQ feedback is for device-to-device communication. A HARQ transmission method for device-to-device communication under a cellular network, wherein the cellular network includes a base station and a first user equipment and a second user equipment based on device-to-device communication, and the method includes the following Step: X. Receiving, by the base station, HARQ feedback from the second user equipment; Y. If the HARQ feedback is a NACK signal and corresponds to the adaptive HARQ, the base station provides the newly allocated resource to the first user equipment; if the HARQ feedback is a NACK signal and corresponds to the non-adaptive HARQ and the semi-static HARQ, Then the base station does not provide the newly allocated resources to the first user equipment. The method of claim 15, wherein the step X further comprises: receiving, by the base station, a device-to-device communication indication message provided by the second user equipment, wherein the device-to-device communication indication message is The indication that the HARQ feedback is for device-to-device communication. A signal transmission method for device-to-device communication under a cellular network, wherein the cellular network includes a base station and a first user equipment and a second user equipment based on device-to-device communication, and the method includes the following Step: - sending, by the second user equipment, a signal to the base station; wherein the signal includes any one of the following: CQI, CSI, PMI, rank Indication, buffer status report, and RRC signal.