CN105917733A

CN105917733A - User equipment, base station and D2D communication method

Info

Publication number: CN105917733A
Application number: CN201480024261.5A
Authority: CN
Inventors: 黎超; 张兴炜
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2014-12-17
Filing date: 2014-12-17
Publication date: 2016-08-31
Anticipated expiration: 2034-12-17
Also published as: WO2016095119A1; CN111200875B; CN111200875A; CN105917733B

Abstract

Disclosed in an embodiment of the present invention are a user equipment (UE), base station and D2D communication method, the method comprising: a second UE receives a transmission signal transmitted by a first UE, the transmission signal being transmitted via a D2D link between the first UE and the second UE; the second UE generates first feedback information according to the transmission signal; the second UE transmits the first feedback information to the first UE. In the embodiment of the present invention, the second UE, as a receiver, generates the first feedback information after receiving the transmission signal transmitted by the first UE via the D2D link, and transmits the first feedback information to the first UE such that the first UE can obtain quality of reception of the second UE, thus ensuring QoS of the D2D communication.

Description

User equipment, base station and D2D communication method

Technical Field

The embodiment of the invention relates to the field of communication, in particular to user equipment, a base station and a D2D communication method.

Background

In a conventional cellular communication system, signaling and data interaction between User Equipments (UEs) need to be forwarded through respective serving base stations and core networks.

Device to Device (D2D) technology is a direct communication technology. Data interaction between the UEs does not need to be forwarded through the base station. The D2D link may be established between UEs, interacting directly or with the assistance of the network.

In the D2D communication in the prior art, the UE as the transmitter transmits in a broadcast manner, that is, the transmitter only manages transmission, and does not know which UE the target receiver is, and the transmitter does not pay attention to the receiving situation of the receiver. The UE as the receiver only performs reception or blind detection on the resources agreed by the system, and the transmitter cannot be informed of the reception quality regardless of whether the data received by the receiver is correct or not. Thus, the Quality of Service (QoS) of D2D communication cannot be guaranteed.

Disclosure of Invention

The embodiment of the invention provides user equipment, a base station and a D2D communication method, which can ensure the QoS of D2D communication.

In a first aspect, a UE is provided, where the UE is a second UE, and the UE includes:

a receiving unit, configured to receive a transmission signal sent by a first UE, where the transmission signal is transmitted through a D2D link between the first UE and the second UE;

the processing unit is used for generating first feedback information according to the transmitting signal received by the receiving unit;

a sending unit, configured to send the first feedback information generated by the processing unit to the first UE.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the transmission signal is a first reference signal, and the first reference signal is used to perform quality measurement on the D2D link,

the first feedback information includes signal quality information and/or transmit power information of the D2D link.

With reference to the first aspect or the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the sending unit is further configured to send the first feedback information to a serving base station of the second UE.

With reference to the first aspect, in a third possible implementation manner of the first aspect, the transmission signal is a data packet,

the first feedback information includes: and the second UE demodulates the data packet to obtain response information, wherein the response information is acknowledgement information ACK which is correctly demodulated or negative acknowledgement information NACK which is incorrectly demodulated.

With reference to the first aspect or the third possible implementation manner of the first aspect, in a fourth possible implementation manner of the first aspect, the data packet includes first indication information, where the first indication information is used to indicate at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.

With reference to the first aspect or any one of the foregoing possible implementations of the first aspect, in a fifth possible implementation of the first aspect, the first feedback information further includes signal quality information and/or transmission power information of the D2D link.

With reference to the first aspect or any one of the foregoing possible implementations of the first aspect, in a sixth possible implementation of the first aspect, the processing unit is further configured to generate second feedback information according to a result of the demodulation, where the second feedback information includes signal quality information and/or transmission power information of the D2D link;

the sending unit is further configured to send the second feedback information generated by the processing unit to a serving base station of the first UE and/or the second UE.

With reference to the first aspect or any one of the foregoing possible implementations of the first aspect, in a seventh possible implementation of the first aspect, the sending unit sends the second feedback information to a serving base station of the second UE,

the second feedback information further includes first indication information, wherein the first indication information is used for indicating at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.

With reference to the first aspect or any one of the foregoing possible implementations of the first aspect, in an eighth possible implementation of the first aspect, before the receiving unit receives a transmission signal sent by a first UE,

the receiving unit is further configured to: receiving Scheduling Assignment (SA) indication information sent by the first UE, wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: modulating coding mode MCS, transmitting power and time-frequency resources;

the receiving unit is specifically configured to: and receiving the transmitting signal sent by the first UE according to the SA indication information.

With reference to the first aspect or any one of the foregoing possible implementations of the first aspect, in a ninth possible implementation of the first aspect, the processing unit is further configured to generate a second reference signal according to the transmission signal, where the second reference signal is determined according to a predefined sequence;

the sending unit is further configured to send the second reference signal to the first UE.

With reference to the first aspect or any one of the foregoing possible implementations of the first aspect, in a tenth possible implementation of the first aspect, the first feedback information includes a second reference signal, where the second reference signal is determined according to a predefined sequence.

With reference to the first aspect or any one of the foregoing possible implementations of the first aspect, in an eleventh possible implementation of the first aspect, the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

the transmission power information includes a value of transmission power and/or adjustment information of transmission power.

With reference to the first aspect or any one of the foregoing possible implementations of the first aspect, in a twelfth possible implementation of the first aspect, the sending unit is specifically configured to send the first feedback information to the first UE according to a feedback resource.

With reference to the first aspect or any one of the foregoing possible implementations of the first aspect, in a thirteenth possible implementation of the first aspect, before the sending unit sends the first feedback information to the first UE,

the receiving unit is further configured to: and receiving configuration information sent by a serving base station of the second UE, wherein the configuration information comprises second indication information, and the second indication information is used for indicating the position of the feedback resource.

With reference to the first aspect or any one of the foregoing possible implementations of the first aspect, in a fourteenth possible implementation of the first aspect, before the sending unit sends the first feedback information to the first UE,

the receiving unit is further configured to acquire association information and receive a transmission resource sent by the first UE, where the association information is used to indicate an association relationship between the transmission resource and the feedback resource, and the association information is predefined or received from a serving base station of the second UE;

the processing unit is further configured to determine the feedback resource according to the association information and the transmission resource.

With reference to the first aspect or any one of the foregoing possible implementation manners of the first aspect, in a fifteenth possible implementation manner of the first aspect, before the sending unit sends the first feedback information to the first UE, the receiving unit is further configured to:

receiving the feedback resource sent by the first UE, wherein the feedback resource is determined by the first UE according to a transmission resource and association information, and the association information is used for indicating an association relationship between the transmission resource and the feedback resource.

With reference to the first aspect or any one of the foregoing possible implementations of the first aspect, in a sixteenth possible implementation of the first aspect, the feedback resource is autonomously selected by the second UE from a feedback resource pool, where the feedback resource pool is preconfigured or the feedback resource pool is received from a serving base station of the second UE.

With reference to the first aspect or any one of the foregoing possible implementation manners of the first aspect, in a seventeenth possible implementation manner of the first aspect, the first UE and the second UE are located in a same cell, and a serving base station of the first UE and a serving base station of the second UE are a same base station.

In a second aspect, a UE is provided, where the UE is a first UE, and includes:

a processing unit for generating a transmission signal;

a sending unit, configured to send the transmission signal generated by the processing unit to a second UE, where the transmission signal is transmitted through a D2D link between the first UE and the second UE;

a receiving unit, configured to receive the first feedback information sent by the second UE.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the transmission signal is a first reference signal, and the first reference signal is used to perform quality measurement on the D2D link,

With reference to the second aspect or the first possible implementation manner of the second aspect, in a second possible implementation manner of the second aspect, the transmission signal is a data packet, and the first feedback information includes acknowledgement information that the second UE demodulates the data packet, where the acknowledgement information is correct demodulation acknowledgement information ACK or incorrect demodulation negative acknowledgement information NACK.

With reference to the second aspect, in a third possible implementation manner of the second aspect, the data packet includes first indication information, where the first indication information is used to indicate at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.

With reference to the second aspect or any one of the foregoing possible implementation manners of the second aspect, in a fourth possible implementation manner of the second aspect, the first feedback information further includes: signal quality information and/or transmit power information for the D2D link.

With reference to the second aspect or any one of the foregoing possible implementation manners of the second aspect, in a fifth possible implementation manner of the second aspect, the receiving unit is further configured to receive second feedback information sent by the second UE, where the second feedback information includes signal quality information and/or transmission power information of the D2D link.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a sixth possible implementation of the second aspect, if the first feedback information includes an ACK, the processing unit is further configured to:

sending a data packet to be sent to the second UE according to the current configuration parameters; alternatively, the first and second electrodes may be,

and stopping the retransmission packet which is not transmitted of the transmitted data packet, and transmitting the new data packet to be transmitted to the second UE according to the current configuration parameters.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a seventh possible implementation of the second aspect, if the first feedback information includes an ACK, the processing unit is further configured to:

adjusting configuration parameters according to the signal quality information and/or the transmitting power information;

and sending the data packet to be sent to the second UE according to the adjusted configuration parameters.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in an eighth possible implementation of the second aspect, if the first feedback information includes a NACK, the processing unit is further configured to:

if the retransmission packet of the sent data packet is not sent completely, sending the retransmission packet of the sent data packet to the second UE according to the current configuration parameters; alternatively, the first and second electrodes may be,

and if the retransmission packet of the sent data packet is sent completely, increasing the retransmission times of the sent data packet or changing a retransmission pattern, and sending the retransmission packet of the sent data packet to the second UE.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a ninth possible implementation of the second aspect, if the first feedback information includes NACK, the processing unit is further configured to:

if the retransmission packet of the sent data packet is not sent completely, adjusting configuration parameters according to the signal quality information and/or the transmitting power information;

and sending the retransmission packet of the sent data packet to the second UE according to the adjusted configuration parameters.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a tenth possible implementation of the second aspect, if the first feedback information includes NACK, the processing unit is further configured to:

if the retransmission packet of the sent data packet is sent completely, adjusting configuration parameters according to the signal quality information and/or the transmitting power information;

and sending the subsequent data packet to the second UE according to the adjusted configuration parameter.

With reference to the second aspect or any one of the foregoing possible implementation manners of the second aspect, in an eleventh possible implementation manner of the second aspect, the receiving unit is further configured to receive first configuration information sent by a serving base station of the first UE, where the first configuration information includes at least one of: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of a used Modulation and Coding Scheme (MCS) and indication information of used time-frequency resources, wherein the first configuration information is determined by a serving base station of the first UE according to second feedback information sent by the second UE;

the processing unit is further configured to adjust configuration parameters according to the first configuration information;

the sending unit is further configured to send a subsequent data packet to the second UE according to the adjusted configuration parameter.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a twelfth possible implementation of the second aspect, the first configuration information further includes information indicating an ID of the D2D link.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a thirteenth possible implementation of the second aspect, the configuration parameter includes at least one of: modulation Coding Scheme (MCS) level, retransmission times, retransmission pattern information, transmitting power information and indication information of time frequency resources.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a fourteenth possible implementation of the second aspect, before the sending unit sends the transmission signal to the second UE, the sending unit is further configured to:

transmitting scheduling assignment SA indication information to the second UE so that the second UE receives the transmission signal according to the SA indication information,

wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: modulation coding scheme MCS, transmitting power and time frequency resources.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a fifteenth possible implementation of the second aspect, the receiving unit is further configured to receive a second reference signal sent by the second UE, where the second reference signal is determined according to a predefined sequence.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a sixteenth possible implementation of the second aspect, the first feedback information further includes a second reference signal, where the second reference signal is determined according to a predefined sequence.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a seventeenth possible implementation of the second aspect, the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in an eighteenth possible implementation of the second aspect, the sending unit is specifically configured to: and sending the transmission signal to the second UE according to the transmission resource.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a nineteenth possible implementation of the second aspect, before the sending unit sends the transmission signal to the second UE, the receiving unit is further configured to:

receiving second configuration information sent by a serving base station of the first UE, wherein the second configuration information includes second indication information, and the second indication information is used for indicating the position of the transmission resource.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a twentieth possible implementation of the second aspect, the transmission resource is autonomously selected by the first UE from a transmission resource pool, wherein the transmission resource pool is preconfigured or the transmission resource pool is received from a serving base station of the first UE.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a twenty-first possible implementation of the second aspect, before the sending unit sends the transmission signal to the second UE,

the receiving unit is further configured to acquire association information and receive a feedback resource sent by the second UE, where the association information is used to indicate an association relationship between the transmission resource and the feedback resource, and the association information is predefined or received from a serving base station of the first UE;

the processing unit is further configured to determine the transmission resource according to the association information and the feedback resource.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a twenty-second possible implementation of the second aspect, before the receiving unit receives the first feedback information sent by the second UE,

the receiving unit is further configured to obtain association information, where the association information is used to indicate an association relationship between the transmission resource and a feedback resource, and the association information is predefined or received from a serving base station of the first UE;

the processing unit is further configured to determine a feedback resource according to the association information and the transmission resource.

With reference to the second aspect or any one of the foregoing possible implementations of the second aspect, in a twenty-third possible implementation of the second aspect, the receiving unit is specifically configured to: and receiving the first feedback information sent by the second UE according to the feedback resource.

With reference to the second aspect or any one of the foregoing possible implementation manners of the second aspect, in a twenty-fourth possible implementation manner of the second aspect, the first UE and the second UE are located in a same cell, and a serving base station of the first UE and a serving base station of the second UE are a same base station.

In a third aspect, a base station is provided, including:

a receiving unit, configured to receive feedback information sent by a second user equipment UE, where the feedback information includes signal quality information and/or transmission power information of a D2D link between a first UE and the second UE;

the processing unit is used for generating first configuration information according to the feedback information received by the receiving unit;

a sending unit, configured to send the first configuration information generated by the processing unit to a first UE, where the base station is a serving base station of the first UE.

With reference to the third aspect, in a first possible implementation manner of the third aspect, the sending unit is further configured to send second configuration information to the first UE,

wherein the second configuration information comprises a transmission resource pool and/or association information for the D2D link, the association information being used for indicating an association relationship between transmission resources and feedback resources.

With reference to the third aspect or the first possible implementation manner of the third aspect, in a second possible implementation manner of the third aspect, the first UE and the second UE are located in a same cell, and the sending unit is further configured to send third configuration information to the second UE,

wherein the third configuration information comprises a feedback resource pool and/or association information for the D2D link, the association information being used for indicating an association between transmission resources and feedback resources.

With reference to the third aspect or the first possible implementation manner of the third aspect, in a third possible implementation manner of the third aspect, the first UE and the second UE are located in different cells, and the receiving unit is specifically configured to:

and receiving feedback information sent by the second UE from a serving base station of the second UE.

With reference to the third aspect or any one of the foregoing possible implementation manners of the third aspect, in a fourth possible implementation manner of the third aspect, the first configuration information includes at least one of: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of Modulation and Coding Scheme (MCS) used and indication information of time-frequency resources used.

With reference to the third aspect or any one of the foregoing possible implementations of the third aspect, in a fifth possible implementation of the third aspect, the first configuration information further includes information used to indicate an identification ID of the D2D link.

With reference to the third aspect or any one of the foregoing possible implementations of the third aspect, in a sixth possible implementation of the third aspect, the feedback information further includes indication information, where the indication information is used to indicate at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.

With reference to the third aspect or any one of the foregoing possible implementations of the third aspect, in a seventh possible implementation of the third aspect, the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

In a fourth aspect, a base station is provided, where the base station is a second base station, and the base station includes:

a receiving unit, configured to receive feedback information sent by a second user equipment UE, where the feedback information includes signal quality information and/or transmission power information of a D2D link between a first UE and the second UE, and the second base station is a serving base station of the second UE;

and the sending unit is used for sending the feedback information received by the receiving unit to a first base station, the first base station is a service base station of first UE, and the first UE and the second UE are located in different cells.

With reference to the fourth aspect, in a first possible implementation manner of the fourth aspect, the sending unit is further configured to send configuration information to the second UE,

wherein the configuration information comprises a feedback resource pool and/or association information for the D2D link, and the association information is used for indicating an association relationship between transmission resources and feedback resources.

With reference to the fourth aspect or the first possible implementation manner of the fourth aspect, in a second possible implementation manner of the fourth aspect, the feedback information further includes indication information, where the indication information is used to indicate at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.

With reference to the fourth aspect or any one of the possible implementations of the fourth aspect, in a third possible implementation of the fourth aspect, the signal quality information includes at least one of the following: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

In a fifth aspect, there is provided a method of device-to-device D2D communication, comprising:

receiving a transmission signal sent by a first UE by a second UE, wherein the transmission signal is transmitted through a D2D link between the first UE and the second UE;

the second UE generates first feedback information according to the transmitting signal;

and the second UE sends the first feedback information to the first UE.

With reference to the fifth aspect, in a first possible implementation manner of the fifth aspect, the transmission signal is a first reference signal, and the first reference signal is used to perform quality measurement on the D2D link,

With reference to the first possible implementation manner of the fifth aspect, in a second possible implementation manner of the fifth aspect, the method further includes:

and the second UE sends the first feedback information to a service base station of the second UE.

With reference to the fifth aspect, in a third possible implementation manner of the fifth aspect, the transmission signal is a data packet,

With reference to the third possible implementation manner of the fifth aspect, in a fourth possible implementation manner of the fifth aspect, the data packet includes first indication information, where the first indication information is used to indicate at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.

With reference to the fifth aspect or any one of the foregoing possible implementations of the fifth aspect, in a fifth possible implementation of the fifth aspect, the first feedback information further includes signal quality information and/or transmission power information of the D2D link.

With reference to the fifth aspect or any one of the possible implementation manners of the fifth aspect, in a sixth possible implementation manner of the fifth aspect, the method further includes:

the second UE generates second feedback information according to the demodulation result, wherein the second feedback information comprises signal quality information and/or transmission power information of the D2D link;

and the second UE sends the second feedback information to the first UE and/or a service base station of the second UE.

With reference to the fifth aspect or any one of the foregoing possible implementations of the fifth aspect, in a seventh possible implementation of the fifth aspect, the second UE sends the second feedback information to a serving base station of the second UE,

With reference to the fifth aspect or any one of the foregoing possible implementation manners of the fifth aspect, in an eighth possible implementation manner of the fifth aspect, before the receiving, by the second UE, the transmission signal sent by the first UE, the method further includes:

the second UE receives scheduling assignment SA indication information sent by the first UE, wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: modulating coding mode MCS, transmitting power and time-frequency resources;

the second UE receiving the transmission signal sent by the first UE, including:

and the second UE receives the transmitting signal sent by the first UE according to the SA indication information.

With reference to the fifth aspect or any one of the foregoing possible implementation manners of the fifth aspect, in a ninth possible implementation manner of the fifth aspect, the method further includes:

the second UE generates a second reference signal according to the transmission signal, wherein the second reference signal is determined according to a predefined sequence;

the second UE sends the second reference signal to the first UE.

With reference to the fifth aspect or any one of the possible implementations of the fifth aspect above, in a tenth possible implementation of the fifth aspect, the first feedback information includes a second reference signal, where the second reference signal is determined according to a predefined sequence.

With reference to the fifth aspect or any one of the possible implementations of the fifth aspect, in an eleventh possible implementation of the fifth aspect, the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

With reference to the fifth aspect or any one of the foregoing possible implementation manners of the fifth aspect, in a twelfth possible implementation manner of the fifth aspect, the sending, by the second UE, the first feedback information to the first UE includes:

and the second UE sends the first feedback information to the first UE according to the feedback resource.

With reference to the fifth aspect or any one of the foregoing possible implementation manners of the fifth aspect, in a thirteenth possible implementation manner of the fifth aspect, before the sending, by the second UE, the first feedback information to the first UE, the method further includes:

and the second UE receives configuration information sent by a serving base station of the second UE, wherein the configuration information comprises second indication information, and the second indication information is used for indicating the position of the feedback resource.

With reference to the fifth aspect or any one of the foregoing possible implementation manners of the fifth aspect, in a fourteenth possible implementation manner of the fifth aspect, before the sending, by the second UE, the first feedback information to the first UE, the method further includes:

the second UE acquires association information and receives the transmission resource sent by the first UE, wherein the association information is used for indicating the association relationship between the transmission resource and the feedback resource, and the association information is predefined or received from a serving base station of the second UE;

and the second UE determines the feedback resource according to the association information and the transmitting resource.

With reference to the fifth aspect or any one of the foregoing possible implementation manners of the fifth aspect, in a fifteenth possible implementation manner of the fifth aspect, before the sending, by the second UE, the first feedback information to the first UE, the method further includes:

and the second UE receives the feedback resource sent by the first UE, wherein the feedback resource is determined by the first UE according to a transmission resource and association information, and the association information is used for indicating an association relation between the transmission resource and the feedback resource.

With reference to the fifth aspect or any one of the foregoing possible implementations of the fifth aspect, in a sixteenth possible implementation of the fifth aspect, the feedback resource is autonomously selected by the second UE from a feedback resource pool, wherein the feedback resource pool is preconfigured or the feedback resource pool is received from a serving base station of the second UE.

With reference to the fifth aspect or any one of the foregoing possible implementation manners of the fifth aspect, in a seventeenth possible implementation manner of the fifth aspect, the first UE and the second UE are located in the same cell, and a serving base station of the first UE and a serving base station of the second UE are the same base station.

In a sixth aspect, there is provided a method of device-to-device D2D communication, comprising:

a first User Equipment (UE) generates a transmission signal;

the first UE sends the transmission signal to a second UE, wherein the transmission signal is transmitted through a D2D link between the first UE and the second UE;

and the first UE receives first feedback information sent by the second UE.

With reference to the sixth aspect, in a first possible implementation manner of the sixth aspect, the transmission signal is a first reference signal, and the first reference signal is used to perform quality measurement on the D2D link,

With reference to the sixth aspect, in a second possible implementation manner of the sixth aspect, the transmission signal is a data packet, and the first feedback information includes acknowledgement information that the second UE demodulates the data packet, where the acknowledgement information is acknowledgement information ACK that is demodulated correctly or negative acknowledgement information NACK that is demodulated incorrectly.

With reference to the second possible implementation manner of the sixth aspect, in a third possible implementation manner of the sixth aspect, the data packet includes first indication information, where the first indication information is used to indicate at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.

With reference to the second possible implementation manner of the sixth aspect or the third possible implementation manner of the sixth aspect, in a fourth possible implementation manner of the sixth aspect, the first feedback information further includes: signal quality information and/or transmit power information for the D2D link.

With reference to the second possible implementation manner of the sixth aspect or the third possible implementation manner of the sixth aspect, in a fifth possible implementation manner of the sixth aspect, the method further includes:

and the first UE receives second feedback information sent by the second UE, wherein the second feedback information comprises signal quality information and/or transmission power information of the D2D link.

With reference to the sixth aspect or any possible implementation manner of the sixth aspect, in a sixth possible implementation manner of the sixth aspect, if the first feedback information includes an ACK, the method further includes:

the first UE sends a data packet to be sent to the second UE according to the current configuration parameters; alternatively, the first and second electrodes may be,

and the first UE stops the retransmission packet which is not transmitted of the transmitted data packet and transmits a new data packet to be transmitted to the second UE according to the current configuration parameters.

With reference to the sixth aspect or any one of the foregoing possible implementation manners of the sixth aspect, in a seventh possible implementation manner of the sixth aspect, if the first feedback information includes an ACK, the method further includes:

the first UE adjusts configuration parameters according to the signal quality information and/or the transmitting power information;

and the first UE sends the data packet to be sent to the second UE according to the adjusted configuration parameters.

With reference to the sixth aspect or any one of the foregoing possible implementation manners of the sixth aspect, in an eighth possible implementation manner of the sixth aspect, if the first feedback information includes a NACK, the method further includes:

if the retransmission packet of the sent data packet is not sent completely, the first UE sends the retransmission packet of the sent data packet to the second UE according to the current configuration parameters; alternatively, the first and second electrodes may be,

if the retransmission packet of the transmitted data packet is already transmitted, the first UE increases the retransmission times of the transmitted data packet or changes the retransmission pattern, and transmits the retransmission packet of the transmitted data packet to the second UE.

With reference to the sixth aspect or any one of the foregoing possible implementation manners of the sixth aspect, in a ninth possible implementation manner of the sixth aspect, if the first feedback information includes NACK, the method further includes:

if the retransmission packet of the sent data packet is not sent completely, the first UE adjusts configuration parameters according to the signal quality information and/or the transmission power information;

and the first UE sends the retransmission packet of the sent data packet to the second UE according to the adjusted configuration parameters.

With reference to the sixth aspect or any one of the foregoing possible implementation manners of the sixth aspect, in a tenth possible implementation manner of the sixth aspect, if the first feedback information includes NACK, the method further includes:

if the retransmission packet of the sent data packet is sent completely, the first UE adjusts configuration parameters according to the signal quality information and/or the transmission power information;

and the first UE sends the subsequent data packet to the second UE according to the adjusted configuration parameters.

With reference to the sixth aspect or any possible implementation manner of the sixth aspect, in an eleventh possible implementation manner of the sixth aspect, the method further includes:

the first UE receives first configuration information sent by a serving base station of the first UE, wherein the first configuration information comprises at least one of the following: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of a used Modulation and Coding Scheme (MCS) and indication information of used time-frequency resources, wherein the first configuration information is determined by a serving base station of the first UE according to second feedback information sent by the second UE;

and the first UE adjusts configuration parameters according to the first configuration information and sends subsequent data packets to the second UE according to the adjusted configuration parameters.

With reference to the eleventh possible implementation manner of the sixth aspect, in a twelfth possible implementation manner of the sixth aspect, the first configuration information further includes information used for indicating an ID of the D2D link.

With reference to the sixth aspect or any one of the possible implementations of the sixth aspect, in a thirteenth possible implementation of the sixth aspect, the configuration parameter includes at least one of: modulation Coding Scheme (MCS) level, retransmission times, retransmission pattern information, transmitting power information and indication information of time frequency resources.

With reference to the sixth aspect or any one of the foregoing possible implementation manners of the sixth aspect, in a fourteenth possible implementation manner of the sixth aspect, before the sending, by the first UE, the transmission signal to the second UE, the method further includes:

the first UE sends scheduling assignment SA indication information to the second UE so that the second UE receives the transmission signal according to the SA indication information,

With reference to the sixth aspect or any one of the possible implementation manners of the sixth aspect, in a fifteenth possible implementation manner of the sixth aspect, the method further includes:

the first UE receives a second reference signal transmitted by the second UE, wherein the second reference signal is determined according to a predefined sequence.

With reference to the sixth aspect or any one of the possible implementations of the sixth aspect above, in a sixteenth possible implementation of the sixth aspect, the first feedback information further includes a second reference signal, wherein the second reference signal is determined according to a predefined sequence.

With reference to the sixth aspect or any one of the possible implementations of the sixth aspect described above, in a seventeenth possible implementation of the sixth aspect,

the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

With reference to the sixth aspect or any one of the possible implementations of the sixth aspect described above, in an eighteenth possible implementation of the sixth aspect,

the first UE sends the transmission signal to a second UE, and the method comprises the following steps:

and the first UE sends the transmission signal to the second UE according to the transmission resource.

With reference to the sixth aspect or any one of the possible implementations of the sixth aspect described above, in a nineteenth possible implementation of the sixth aspect,

before the first UE sends the transmission signal to a second UE, the method further includes:

the first UE receives second configuration information sent by a serving base station of the first UE, wherein the second configuration information comprises second indication information, and the second indication information is used for indicating the position of the transmission resource.

With reference to the sixth aspect or any one of the possible implementations of the sixth aspect above, in a twentieth possible implementation of the sixth aspect,

the transmission resource is autonomously selected by the first UE from a pool of transmission resources, wherein the pool of transmission resources is pre-configured or received from a serving base station of the first UE.

With reference to the sixth aspect or any one of the possible implementations of the sixth aspect above, in a twenty-first possible implementation of the sixth aspect,

the first UE acquires association information and receives a feedback resource sent by the second UE, wherein the association information is used for indicating an association relation between the transmission resource and the feedback resource, and the association information is predefined or received from a serving base station of the first UE;

and the first UE determines the transmitting resource according to the associated information and the feedback resource.

With reference to the sixth aspect or any one of the possible implementations of the sixth aspect above, in a twenty-second possible implementation of the sixth aspect,

before the first UE receives the first feedback information sent by the second UE, the method further includes:

the first UE acquires association information, wherein the association information is used for indicating an association relation between the transmission resource and a feedback resource, and the association information is predefined or received from a serving base station of the first UE;

and the first UE determines a feedback resource according to the association information and the transmitting resource.

With reference to the sixth aspect or any one of the possible implementations of the sixth aspect above, in a twenty-third possible implementation of the sixth aspect,

the first UE receiving the first feedback information sent by the second UE, including:

and the first UE receives the first feedback information sent by the second UE according to the feedback resource.

With reference to the sixth aspect or any one of the possible implementations of the sixth aspect above, in a twenty-fourth possible implementation of the sixth aspect,

the first UE and the second UE are located in the same cell, and the serving base station of the first UE and the serving base station of the second UE are the same base station.

In a seventh aspect, a method for device-to-device D2D communication is provided, comprising:

a base station receives feedback information sent by a second User Equipment (UE), wherein the feedback information comprises signal quality information and/or transmission power information of a D2D link between a first UE and the second UE;

the base station generates first configuration information according to the feedback information;

and the base station sends the first configuration information to first UE, wherein the base station is a service base station of the first UE.

With reference to the seventh aspect, in a first possible implementation manner of the seventh aspect, the method further includes:

the base station transmitting second configuration information to the first UE,

With reference to the seventh aspect or the first possible implementation manner of the seventh aspect, in a second possible implementation manner of the seventh aspect, the method for controlling a UE includes that the first UE and the second UE are located in a same cell, and the method further includes:

the base station transmitting third configuration information to the second UE,

With reference to the seventh aspect or the first possible implementation manner of the seventh aspect, in a third possible implementation manner of the seventh aspect, the first UE and the second UE are located in different cells, and the receiving, by the base station, feedback information sent by the second UE includes:

and the base station receives the feedback information sent by the second UE from the serving base station of the second UE.

With reference to the seventh aspect or any one of the possible implementation manners of the seventh aspect, in a fourth possible implementation manner of the seventh aspect, the first configuration information includes at least one of: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of Modulation and Coding Scheme (MCS) used and indication information of time-frequency resources used.

With reference to the fourth possible implementation manner of the seventh aspect, in a fifth possible implementation manner of the seventh aspect, the first configuration information further includes information used for indicating an identification ID of the D2D link.

With reference to the seventh aspect or any one of the possible implementations of the seventh aspect, in a sixth possible implementation of the seventh aspect, the feedback information further includes indication information, where the indication information is used to indicate at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.

With reference to the seventh aspect or any one of the possible implementations of the seventh aspect, in a seventh possible implementation of the seventh aspect, the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

In an eighth aspect, there is provided a method for device-to-device D2D communication, comprising:

a second base station receives feedback information sent by a second User Equipment (UE), wherein the feedback information comprises signal quality information and/or transmission power information of a D2D link between a first UE and the second UE, and the second base station is a serving base station of the second UE;

and the second base station sends the feedback information to a first base station, the first base station is a service base station of first UE, and the first UE and the second UE are located in different cells.

With reference to the eighth aspect, in a first possible implementation manner of the eighth aspect, the method further includes:

the second base station sends configuration information to the second UE,

With reference to the eighth aspect or the first possible implementation manner of the eighth aspect, in a second possible implementation manner of the eighth aspect, the feedback information further includes indication information, where the indication information is used to indicate at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.

With reference to the eighth aspect or any one of the above possible implementation manners of the eighth aspect, in a third possible implementation manner of the eighth aspect, the signal quality information includes at least one of the following: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

In a ninth aspect, a UE is provided, where the UE is a second UE, and the method includes:

a receiver, configured to receive a transmission signal sent by a first UE, where the transmission signal is transmitted over a D2D link between the first UE and the second UE;

a processor for generating first feedback information from the transmission signal received by the receiver;

a transmitter configured to transmit the first feedback information generated by the processor to the first UE.

With reference to the ninth aspect, in a first possible implementation manner of the ninth aspect, the transmission signal is a first reference signal, and the first reference signal is used to perform quality measurement on the D2D link,

With reference to the ninth aspect or the first possible implementation manner of the ninth aspect, in a second possible implementation manner of the ninth aspect, the transmitter is further configured to send the first feedback information to a serving base station of the second UE.

With reference to the ninth aspect, in a third possible implementation manner of the ninth aspect, the transmission signal is a data packet,

With reference to the ninth aspect or the third possible implementation manner of the ninth aspect, in a fourth possible implementation manner of the ninth aspect, the data packet includes first indication information, where the first indication information is used to indicate at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.

With reference to the ninth aspect or any one of the foregoing possible implementations of the ninth aspect, in a fifth possible implementation of the ninth aspect, the first feedback information further includes signal quality information and/or transmission power information of the D2D link.

With reference to the ninth aspect or any one of the foregoing possible implementation manners of the ninth aspect, in a sixth possible implementation manner of the ninth aspect, the processor is further configured to generate second feedback information according to a result of the demodulation, where the second feedback information includes signal quality information and/or transmission power information of the D2D link;

the transmitter is further configured to transmit the second feedback information generated by the processor to a serving base station of the first UE and/or the second UE.

With reference to the ninth aspect or any one of the foregoing possible implementations of the ninth aspect, in a seventh possible implementation of the ninth aspect, the transmitter transmits the second feedback information to a serving base station of the second UE,

With reference to the ninth aspect or any one of the foregoing possible implementations of the ninth aspect, in an eighth possible implementation of the ninth aspect, before the receiver receives the transmission signal sent by the first UE,

the receiver is further configured to: receiving Scheduling Assignment (SA) indication information sent by the first UE, wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: modulating coding mode MCS, transmitting power and time-frequency resources;

the receiver is specifically configured to: and receiving the transmitting signal sent by the first UE according to the SA indication information.

With reference to the ninth aspect or any one of the foregoing possible implementations of the ninth aspect, in a ninth possible implementation of the ninth aspect, the processor is further configured to generate a second reference signal according to the transmission signal, where the second reference signal is determined according to a predefined sequence;

the transmitter is further configured to transmit the second reference signal to the first UE.

With reference to the ninth aspect or any one of the possible implementations of the ninth aspect above, in a tenth possible implementation of the ninth aspect, the first feedback information includes a second reference signal, where the second reference signal is determined according to a predefined sequence.

With reference to the ninth aspect or any one of the possible implementation manners of the ninth aspect, in an eleventh possible implementation manner of the ninth aspect, the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

With reference to the ninth aspect or any one of the foregoing possible implementation manners of the ninth aspect, in a twelfth possible implementation manner of the ninth aspect, the transmitter is specifically configured to send the first feedback information to the first UE according to a feedback resource.

With reference to the ninth aspect or any one of the possible implementations of the ninth aspect, in a thirteenth possible implementation of the ninth aspect, before the transmitter transmits the first feedback information to the first UE,

the receiver is further configured to: and receiving configuration information sent by a serving base station of the second UE, wherein the configuration information comprises second indication information, and the second indication information is used for indicating the position of the feedback resource.

With reference to the ninth aspect or any one of the foregoing possible implementations of the ninth aspect, in a fourteenth possible implementation of the ninth aspect, before the transmitter transmits the first feedback information to the first UE,

the receiver is further configured to obtain association information, and receive a transmission resource sent by the first UE, where the association information is used to indicate an association relationship between the transmission resource and the feedback resource, and the association information is predefined or received from a serving base station of the second UE;

the processor is further configured to determine the feedback resource according to the association information and the transmission resource.

With reference to the ninth aspect or any one of the foregoing possible implementations of the ninth aspect, in a fifteenth possible implementation of the ninth aspect, before the transmitter transmits the first feedback information to the first UE, the receiver is further configured to:

With reference to the ninth aspect or any one of the foregoing possible implementations of the ninth aspect, in a sixteenth possible implementation of the ninth aspect, the feedback resource is autonomously selected by the second UE from a feedback resource pool, wherein the feedback resource pool is preconfigured or the feedback resource pool is received from a serving base station of the second UE.

With reference to the ninth aspect or any one of the foregoing possible implementation manners of the ninth aspect, in a seventeenth possible implementation manner of the ninth aspect, the first UE and the second UE are located in a same cell, and a serving base station of the first UE and a serving base station of the second UE are a same base station.

In a tenth aspect, a UE is provided, where the UE is a first UE, and includes:

a processor for generating a transmit signal;

a transmitter configured to transmit the transmit signal generated by the processor to a second UE, wherein the transmit signal is transmitted over a D2D link between the first UE and the second UE;

a receiver, configured to receive the first feedback information sent by the second UE.

With reference to the tenth aspect, in a first possible implementation manner of the tenth aspect, the transmission signal is a first reference signal, and the first reference signal is used to perform quality measurement on the D2D link,

With reference to the tenth aspect or the first possible implementation manner of the tenth aspect, in a second possible implementation manner of the tenth aspect, the transmission signal is a data packet, and the first feedback information includes acknowledgement information that the second UE demodulates the data packet, where the acknowledgement information is correct acknowledgement information ACK or incorrect negative acknowledgement information NACK.

With reference to the tenth aspect, in a third possible implementation manner of the tenth aspect, the data packet includes first indication information, where the first indication information is used to indicate at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.

With reference to the tenth aspect or any one of the possible implementation manners of the tenth aspect, in a fourth possible implementation manner of the tenth aspect, the first feedback information further includes: signal quality information and/or transmit power information for the D2D link.

With reference to the tenth aspect or any one of the foregoing possible implementation manners of the tenth aspect, in a fifth possible implementation manner of the tenth aspect, the receiver is further configured to receive second feedback information sent by the second UE, where the second feedback information includes signal quality information and/or transmission power information of the D2D link.

With reference to the tenth aspect or any one of the foregoing possible implementations of the tenth aspect, in a sixth possible implementation of the tenth aspect, if the first feedback information includes an ACK, the processor is further configured to:

With reference to the tenth aspect or any one of the foregoing possible implementations of the tenth aspect, in a seventh possible implementation of the tenth aspect, if the first feedback information includes an ACK, the processor is further configured to:

With reference to the tenth aspect or any one of the foregoing possible implementations of the tenth aspect, in an eighth possible implementation of the tenth aspect, if the first feedback information includes NACK, the processor is further configured to:

With reference to the tenth aspect or any one of the foregoing possible implementations of the tenth aspect, in a ninth possible implementation of the tenth aspect, if the first feedback information includes NACK, the processor is further configured to:

With reference to the tenth aspect or any one of the foregoing possible implementations of the tenth aspect, in a tenth possible implementation of the tenth aspect, if the first feedback information includes a NACK, the processor is further configured to:

With reference to the tenth aspect or any one of the foregoing possible implementation manners of the tenth aspect, in an eleventh possible implementation manner of the tenth aspect, the receiver is further configured to receive first configuration information sent by a serving base station of the first UE, where the first configuration information includes at least one of: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of a used Modulation and Coding Scheme (MCS) and indication information of used time-frequency resources, wherein the first configuration information is determined by a serving base station of the first UE according to second feedback information sent by the second UE;

the processor is further configured to adjust configuration parameters according to the first configuration information;

the transmitter is further configured to transmit a subsequent data packet to the second UE according to the adjusted configuration parameter.

With reference to the tenth aspect or any one of the foregoing possible implementations of the tenth aspect, in a twelfth possible implementation of the tenth aspect, the first configuration information further includes information indicating an ID of the D2D link.

With reference to the tenth aspect or any one of the possible implementations of the tenth aspect, in a thirteenth possible implementation of the tenth aspect, the configuration parameter includes at least one of: modulation Coding Scheme (MCS) level, retransmission times, retransmission pattern information, transmitting power information and indication information of time frequency resources.

With reference to the tenth aspect or any one of the foregoing possible implementations of the tenth aspect, in a fourteenth possible implementation of the tenth aspect, before the transmitter transmits the transmission signal to the second UE, the transmitter is further configured to:

With reference to the tenth aspect or any one of the foregoing possible implementations of the tenth aspect, in a fifteenth possible implementation of the tenth aspect, the receiver is further configured to receive a second reference signal transmitted by the second UE, where the second reference signal is determined according to a predefined sequence.

With reference to the tenth aspect or any one of the possible implementations of the tenth aspect, in a sixteenth possible implementation of the tenth aspect, the first feedback information further includes a second reference signal, where the second reference signal is determined according to a predefined sequence.

With reference to the tenth aspect or any one of the possible implementations of the tenth aspect, in a seventeenth possible implementation of the tenth aspect, the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

With reference to the tenth aspect or any one of the foregoing possible implementations of the tenth aspect, in an eighteenth possible implementation of the tenth aspect, the transmitter is specifically configured to: and sending the transmission signal to the second UE according to the transmission resource.

With reference to the tenth aspect or any one of the foregoing possible implementations of the tenth aspect, in a nineteenth possible implementation of the tenth aspect, before the transmitter transmits the transmission signal to the second UE, the receiver is further configured to:

With reference to the tenth aspect or any one of the above possible implementations of the tenth aspect, in a twentieth possible implementation of the tenth aspect, the transmission resource is autonomously selected by the first UE from a transmission resource pool, wherein the transmission resource pool is pre-configured or received from a serving base station of the first UE.

With reference to the tenth aspect or any one of the possible implementations of the tenth aspect, in a twenty-first possible implementation of the tenth aspect, before the transmitter transmits the transmission signal to the second UE,

the receiver is further configured to obtain association information, and receive a feedback resource sent by the second UE, where the association information is used to indicate an association relationship between the transmission resource and the feedback resource, and the association information is predefined or received from a serving base station of the first UE;

the processor is further configured to determine the transmission resource according to the association information and the feedback resource.

With reference to the tenth aspect or any one of the foregoing possible implementations of the tenth aspect, in a twenty-second possible implementation of the tenth aspect, before the receiver receives the first feedback information sent by the second UE,

the receiver is further configured to obtain association information, where the association information is used to indicate an association relationship between the transmission resources and feedback resources, and the association information is predefined or received from a serving base station of the first UE;

the processor is further configured to determine a feedback resource according to the association information and the transmission resource.

With reference to the tenth aspect or any one of the foregoing possible implementations of the tenth aspect, in a twenty-third possible implementation of the tenth aspect, the receiver is specifically configured to: and receiving the first feedback information sent by the second UE according to the feedback resource.

With reference to the tenth aspect or any one of the foregoing possible implementation manners of the tenth aspect, in a twenty-fourth possible implementation manner of the tenth aspect, the first UE and the second UE are located in the same cell, and a serving base station of the first UE and a serving base station of the second UE are the same base station.

In an eleventh aspect, there is provided a base station comprising:

a receiver, configured to receive feedback information sent by a second user equipment UE, where the feedback information includes signal quality information and/or transmission power information of a D2D link between a first UE and the second UE;

a processor configured to generate first configuration information according to the feedback information received by the receiver;

a transmitter, configured to transmit the first configuration information generated by the processor to a first UE, where the base station is a serving base station of the first UE.

With reference to the eleventh aspect, in a first possible implementation manner of the eleventh aspect, the transmitter is further configured to transmit second configuration information to the first UE,

With reference to the eleventh aspect or the first possible implementation manner of the eleventh aspect, in a second possible implementation manner of the eleventh aspect, the first UE and the second UE are located in a same cell, and the transmitter is further configured to transmit third configuration information to the second UE,

With reference to the eleventh aspect or the first possible implementation manner of the eleventh aspect, in a third possible implementation manner of the eleventh aspect, the first UE and the second UE are located in different cells, and the receiver is specifically configured to:

With reference to the eleventh aspect or any one of the possible implementations of the eleventh aspect, in a fourth possible implementation of the eleventh aspect, the first configuration information includes at least one of: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of Modulation and Coding Scheme (MCS) used and indication information of time-frequency resources used.

With reference to the eleventh aspect or any one of the foregoing possible implementations of the eleventh aspect, in a fifth possible implementation of the eleventh aspect, the first configuration information further includes information indicating an identification ID of the D2D link.

With reference to the eleventh aspect or any one of the foregoing possible implementation manners of the eleventh aspect, in a sixth possible implementation manner of the eleventh aspect, the feedback information further includes indication information, where the indication information is used to indicate at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.

With reference to the eleventh aspect or any one of the possible implementations of the eleventh aspect, in a seventh possible implementation of the eleventh aspect, the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

In a twelfth aspect, a base station is provided, where the base station is a second base station, and the base station includes:

a receiver, configured to receive feedback information sent by a second user equipment UE, where the feedback information includes signal quality information and/or transmission power information of a D2D link between a first UE and the second UE, and the second base station is a serving base station of the second UE;

a transmitter, configured to send the feedback information received by the receiver to a first base station, where the first base station is a serving base station of a first UE, and the first UE and the second UE are located in different cells.

With reference to the twelfth aspect, in a first possible implementation manner of the twelfth aspect, the transmitter is further configured to transmit configuration information to the second UE,

With reference to the twelfth aspect or the first possible implementation manner of the twelfth aspect, in a second possible implementation manner of the twelfth aspect, the feedback information further includes indication information, where the indication information is used to indicate at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.

With reference to the twelfth aspect or any one of the foregoing possible implementations of the twelfth aspect, in a third possible implementation of the twelfth aspect, the signal quality information includes at least one of the following: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

In the embodiment of the present invention, after receiving a transmission signal sent by a first UE through a D2D link, a second UE serving as a receiver generates first feedback information and sends the first feedback information to the first UE. The first UE can acquire the receiving quality of the second UE, so that the QoS of D2D communication can be guaranteed.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 is a schematic diagram of a scenario in which a first UE and a second UE are located in the same cell.

Fig. 2 is a schematic diagram of a scenario in which a first UE and a second UE are located in different cells.

Fig. 3 is a block diagram of a user equipment according to an embodiment of the present invention.

Fig. 4 is a block diagram of a user equipment according to another embodiment of the present invention.

Fig. 5 is a block diagram of a base station according to an embodiment of the present invention.

Fig. 6 is a block diagram of a base station according to another embodiment of the present invention.

Fig. 7 is a flow chart of a method of D2D communication according to one embodiment of the invention.

Fig. 8 shows an example of a signal transmitted by the first UE according to the embodiment of the present invention.

Fig. 9 is a flow chart of a method of D2D communication according to another embodiment of the invention.

Fig. 10 is another example of a signal transmitted by the first UE according to the embodiment of the present invention.

Fig. 11 is another example of a signal transmitted by the first UE according to an embodiment of the present invention.

Fig. 12 is another example of a signal transmitted by the first UE according to the embodiment of the present invention.

Fig. 13 is a flow chart of a method for D2D communication according to another embodiment of the invention.

Fig. 14 is a flow chart of a method for D2D communication according to another embodiment of the invention.

Fig. 15 is a signaling flow diagram of D2D communication according to one embodiment of the invention.

Fig. 16 is a signaling flow diagram of D2D communication according to another embodiment of the present invention.

Fig. 17 is a signaling flow diagram of D2D communication according to another embodiment of the present invention.

Fig. 18 is a signaling flow diagram of D2D communication according to another embodiment of the present invention.

Fig. 19 is a block diagram of a user equipment according to another embodiment of the present invention.

Fig. 20 is a block diagram of a user equipment according to another embodiment of the present invention.

Fig. 21 is a block diagram of a base station according to another embodiment of the present invention.

Fig. 22 is a block diagram of a base station according to another embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be understood that the technical solutions of the embodiments of the present invention can be applied to various communication systems, for example: a Global System for Mobile communications (GSM) System, a Code Division Multiple Access (CDMA) System, a Wideband Code Division Multiple Access (WCDMA) System, a General Packet Radio Service (GPRS), a Long Term Evolution (Long Term Evolution, LTE) System, an LTE Frequency Division Duplex (FDD) System, an LTE Time Division Duplex (TDD), a Universal Mobile Telecommunications System (UMTS), and the like.

A UE may also be referred to as a terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a mobile terminal, a wireless communication device, a user agent, or a user equipment, and may communicate with one or more core networks via a Radio Access Network (RAN). For example, a UE may be a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device having Wireless communication capabilities, a computing device, or other processing device connected to a Wireless modem. The invention is not limited in this regard. The UE related in the embodiment of the invention is the UE supporting the D2D function.

The Base Station may be a Base Transceiver Station (BTS) in GSM or CDMA, a Base Station (NodeB) in WCDMA, or an eNB or e-NodeB in LTE, which is not limited in the present invention.

It should be noted that in the embodiment of the present invention, the link for direct communication between devices is represented by D2D, but it is understood that the link for direct communication between devices may also be represented by a Sidelink (SL) to distinguish from a cellular link, which is not limited in the present invention. That is, D2D in the embodiment of the present invention may be replaced with SL. In the embodiment of the present invention, the Control Information of the D2D link is represented by Scheduling Assignment (SA) indication Information, or the Control Information of the D2D link may be represented by side link Control Information (SCI), which is not limited in the present invention. That is, the SA indication information in the embodiment of the present invention may be replaced with SCI. The Channel for transmitting SCI may be a Physical Sidelink Control Channel (PSCCH). In the embodiment of the present invention, the control Channel used for the D2D link synchronization source transmission is represented by a Physical D2D synchronization Channel (PD 2DSCH), or may be represented by a Sidelink Broadcast Channel (SL-BCH), which is not limited in the present invention. That is, the PD2DSCH in the embodiment of the present invention may be replaced with SL-BCH.

D2D communication means that one UE transmits control information and data, and the other UE reads the control information to obtain information such as the transmission format of the subsequent data, so as to correctly receive the subsequent data.

D2D communication is divided into two modes: mode 1(mode 1) and mode 2(mode 2). Here, the mode 1 refers to a resource that a base station or a relay (relay) node schedules the UE for transmitting data and control information of D2D. Specifically, the control information may be a Scheduling Assignment (SA) message. When the mode 1 of D2D communication is adopted, the base station instructs the UE to transmit scheduling assignment and resources, formats, etc. of data through downlink signaling. Mode 2 refers to the UE itself selecting resources for transmitting data of direct communication and SA messages from a resource pool (which may be referred to as a mode 2 resource pool of D2D communication), wherein the mode 2 resource pool of D2D communication may include an SA message resource pool and a resource pool of data corresponding to SA messages. In other words, the UE may select a resource for transmitting the SA message from the SA message resource pool, and select a resource for transmitting data corresponding to the SA message from the SA message resource pool.

The resource pool may comprise a set of time frequency resources, which is a set of multiple time frequency resources.

In the embodiment of the present invention, it is assumed that the UE serving as a transmitter in the D2D communication is a first UE, and the UE serving as a receiver is a second UE. Also, the D2D communication is over a D2D link between the first UE and the second UE.

Wherein the first UE and the second UE may be located in the same cell, as shown in fig. 1, the first UE 110 and the second UE 120 are both located in the cell 100 of the base station 130. That is, the base station 130 is both the serving base station for the first UE 110 and the serving base station for the second UE 120. It is understood that the first UE 110 communicates with the base station 130 over a cellular link, the second UE 120 communicates with the base station 130 over a cellular link, and the first UE 110 communicates with the second UE 120 over a D2D link.

Wherein, the first UE and the second UE may be located in different cells, as shown in fig. 2, the first UE 210 is located in the cell 201 of the first base station 230, and the second UE 220 is located in the cell 202 of the second base station 240. That is, the first base station 230 is a serving base station for the first UE 210, and the second base station 240 is a serving base station for the second UE 220. It is understood that the first UE 110 communicates with the first base station 230 via a cellular link, the second UE 120 communicates with the second base station 240 via a cellular link, and the first UE 110 communicates with the second UE 120 via a D2D link.

Fig. 3 is a block diagram of a user equipment according to an embodiment of the present invention. The UE 300 shown in fig. 3 is a second UE and comprises a receiving unit 301, a processing unit 302 and a transmitting unit 303.

A receiving unit 301, configured to receive a transmission signal sent by a first UE, where the transmission signal is transmitted through a D2D link between the first UE and the second UE;

a processing unit 302, configured to generate first feedback information according to the transmission signal received by the receiving unit 301;

a sending unit 303, configured to send the first feedback information generated by the processing unit 302 to the first UE.

It is to be understood that the sending unit 303 sends the first feedback information to the first UE through the D2D link.

Alternatively, the processor may, as an embodiment,

the transmission signal received by the receiving unit 301 may be a first reference signal, and the first reference signal is used for performing quality measurement on the D2D link. Then the first feedback information generated by the processing unit 302 may comprise signal quality information and/or transmit power information of said D2D link.

For example, the first reference Signal may be a D2D Synchronization Signal (D2D Synchronization Signal, D2 DSS). Alternatively, the first reference signal may be a newly defined reference signal dedicated for D2D channel quality measurement. The invention is not limited in this regard.

The UE 300 may estimate the signal quality of the D2D link from the transmitted signal and generate signal quality information. Wherein the signal quality information may include at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI), and adjustment information for the CQI. The transmission power information may include a value of transmission power and/or adjustment information of transmission power.

Specifically, the UE 300 may prestore all supported antenna configurations and equivalent Signal to Noise Ratio (SNR) thresholds that can be correctly demodulated under various Modulation and Coding Scheme (MCS) levels.

The UE 300 may calculate a current equivalent SNR value from the transmitted signal. Further, the UE 300 may calculate the CQI, the adjustment information Δ CQI of the CQI, and the adjustment information Δ P of the transmission power according to the equivalent SNR value. In this way, the processing unit 302 may be generating the first feedback information.

Optionally, the sending unit 303 may also send the first feedback information to the serving base station of the second UE through the cellular link, so that the serving base station of the second UE acquires the channel quality information of the D2D link.

Optionally, the sending unit 303 may send the first feedback information to the first UE according to a feedback resource.

For example, the receiving unit 301 may receive configuration information sent by a serving base station of the second UE, where the configuration information includes second indication information, and the second indication information is used to indicate a location of the feedback resource; and the second UE determines the feedback resource according to the configuration information.

It is understood that the serving base station of the second UE may send the configuration information to the second UE through signaling. The signaling may be common signaling, such as a System Information Block (SIB). Alternatively, the signaling may be Radio Resource Control (RRC) signaling common to the cells. Alternatively, the signaling may be a dedicated signaling sent to the second UE, such as Downlink Control Information (DCI) signaling. Alternatively, the signaling may be dedicated RRC signaling. The invention is not limited in this regard.

As another example, the receiving unit 301 may obtain association information and receive the transmission resource sent by the first UE; further, the processing unit 302 may determine the feedback resource according to the association information and the transmission resource. Wherein the association information is used for indicating an association relationship between the transmission resources and the feedback resources, and the association information may be predefined or received from a serving base station of the second UE.

Wherein the first UE may send the transmission resources to the second UE through an SA control Channel, or through a Physical D2D Synchronization Channel (Physical D2D Synchronization Channel), or through a data Channel. For example, the first UE may send the transmission resources to the second UE by sending SA indication information.

It is understood that the association information may be preconfigured on the second UE, or the serving base station of the second UE may send the association information to the second UE through signaling.

It is appreciated that the transmit resource pool may be preconfigured on the first UE, or the serving base station of the first UE may signal the first UE with the transmit resource pool for the unicast link. In this way, the first UE may select a transmission resource from the pool of transmission resources. Here, the transmission resource pool is a set of transmission resources.

Further, the processing unit 302 may calculate feedback resources according to the transmission resources and the association information.

For example, the processing unit 302 may calculate the frequency domain locations included in the feedback resources by (a × Nprb + b) mod Nm. Where Nprb is the location of the transmit resource in the frequency domain, Nm is the maximum number of feedback resources provided, and mod represents the modulo operation. Where a and b are predefined, often real numbers, such as a 1, b Nm/2; alternatively, the term "a" -1 and "b" -Nm/4.

For example, the processing unit 302 may calculate the position of the radio frame or subframe occupied in the time domain included in the feedback resource. It may be the time domain location of the nearest D2D feedback resource after receiving the transmission resource and after a certain time threshold (e.g. 4 ms). For example, when the currently transmitted data packet is received in the 3 rd subframe in the current radio frame, the subframe 6 and the subframe 8 both have the feedback resource nearest to the currently transmitted data packet, but the interval between the subframe 6 and the subframe 3 is less than the threshold 4ms, so the subframe 8 is selected as the time domain position of the feedback resource.

As another example, the receiving unit 301 may receive the feedback resource transmitted by the first UE. Wherein the feedback resource is determined by the first UE according to a transmission resource and from association information indicating an association between the transmission resource and the feedback resource.

It is appreciated that the transmission resources and associated information may be received by the first UE from a serving base station of the first UE; alternatively, the transmission resources and association information may be pre-configured on the first UE; alternatively, the transmission resource may be received by the first UE from a serving base station of the first UE and the association information is pre-configured on the first UE.

It is to be appreciated that the transmit resource pool and the association information can be preconfigured on the first UE. Alternatively, the association information may be preconfigured on the first UE and the serving base station of the first UE signals to the first UE a pool of transmission resources for the unicast link. Alternatively, the serving base station of the first UE may configure the first UE with the transmission resource pool and the association information for the unicast link through signaling. In this way, the first UE may select a transmission resource from the pool of transmission resources and determine a feedback resource based on the transmission resource and the association information.

As another example, the feedback resource may be autonomously selected by the second UE from a feedback resource pool, wherein the feedback resource pool is pre-configured or received from a serving base station of the second UE.

It is to be appreciated that a feedback resource pool can be preconfigured on the second UE. Or the serving base station of the second UE may configure the feedback resource pool for the unicast link to the second UE through signaling. Here, the feedback resource pool is a set of feedback resources.

In the embodiment of the invention, the association information is used for indicating the association relationship between the transmission resources and the feedback resources. For example, the association relationship may include: an offset value exists between the transmission power included in the feedback resource and the transmission power included in the transmission resource according to a predefined rule. Alternatively, the association relationship may include: the feedback resource includes a Cyclic Prefix (CP) type identical to a CP type included in the transmission resource.

Here, the transmission power included in the feedback resource may be understood as the transmission power when the second UE transmits the first feedback information to the first UE, or may be simply referred to as the transmission power fed back by the second UE. The transmission power included in the transmission resource may be understood as the transmission power when the first UE transmits the transmission signal, or may be simply referred to as the transmission power transmitted by the first UE.

Then, according to the above-mentioned association information, the transmission power when the second UE feeds back has an offset value according to a predefined rule than the transmission power when the first UE transmits. For example, the difference between the transmission power fed back by the second UE and the transmission power transmitted by the first UE may be expressed as the difference obtained by subtracting the transmission power transmitted by the first UE from the transmission power fed back by the second UE. Wherein the difference may be a fixed value, e.g. the difference equals 3dB or-3 dB. Alternatively, the difference may be calculated by other available parameters. For example, the difference may be related to the MCS level; that is, the difference may be determined according to the MCS level at the time of feedback by the second UE and the MCS level at the time of transmission by the first UE. The invention is not limited in this regard.

Alternatively, as another embodiment,

the transmission signal received by the receiving unit 301 may be a data packet. Then, the first feedback information generated by the processing unit 302 may include the response information after the second UE demodulates the data packet. Wherein, the response information is Acknowledgement information (ACK) with correct demodulation or Negative Acknowledgement information (NACK) with wrong demodulation.

The processing unit 302 may demodulate the data packet and determine whether the demodulation is correct by decoding. If the demodulation is correct, the response information is ACK; if the demodulation is wrong, the response information is NACK.

Optionally, the first feedback information may further include signal quality information and/or transmission power information of the D2D link. Or, optionally, the processing unit 302 generates second feedback information according to the demodulation result, and the sending unit 303 sends the second feedback information to the serving base station of the first UE and/or the second UE. Wherein the second feedback information comprises signal quality information and/or transmit power information of the D2D link.

The sending unit 303 may send the second feedback information to the first UE through the D2D link, and may send the second feedback information to the serving base station of the second UE through the cellular link.

Specifically, the processing unit 302 may estimate the signal quality of the D2D link from the transmitted signal and generate signal quality information.

Wherein the signal quality information may include at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI. The transmission power information may include a value of transmission power and/or adjustment information of transmission power. For the process of estimating the signal quality information by the second UE and the process of calculating the transmission power information by the second UE, reference may be made to the description of the foregoing embodiments, and details are not repeated here in order to avoid repetition.

It is understood that the RSRP, RSRQ, RSSI, and CQI may be determined by the second UE according to a DeModulation Reference Signal (DMRS) included in the data packet. That is, the data packet includes the DMRS.

And when the data packet transmitted by the first UE is a data packet in a PD2DSCH channel, the Signal quality information may be determined based on a DMRS in the PD2DSCH or may be determined based on a D2D Synchronization Signal (D2D Synchronization Signal, D2DSS) transmitted together with the PD2 DSCH. And further, the data packet may be one or more of: SA, data corresponding to the data packet, and data packet included in PD2 DSCH.

Optionally, the data packet sent by the first UE to the second UE may include the first indication information. Wherein the first indication information is used for indicating at least one of the following: an Identity (ID) of the first UE, an ID of the second UE, and an ID of the D2D link. Thus, the second UE may know from the data packets received from the first UE who the first UE is, and/or who its target UE is, and/or which of the target D2D links is.

Optionally, the sending unit 303 may send second feedback information to the serving base station of the second UE, where the second feedback information may further include the first indication information. Wherein the first indication information is used for indicating at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.

In this way, the serving base station of the second UE may know to which D2D link the signal quality information and/or the transmit power information in the second feedback information is directed.

For example, the ID of the first UE may be an International Mobile Subscriber Identity (IMSI) number of the first UE, or may be a network temporary identifier of the first UE. The ID of the second UE may be the MISI number of the second UE, or may be a network temporary identifier of the second UE. The ID of the D2D link may be a Radio Network Temporary Identity (RNTI) of the D2D link, that is, D2D-RNTI.

It should be noted that, in the embodiment of the present invention, the order of the sending time of the first feedback information and the second feedback information is not limited.

For example, the second UE may send the first feedback information and the second feedback information to the first UE simultaneously. Or, the second UE may also send the first feedback information to the first UE first, so that the first UE determines whether the last data transmission is correct in a short time; and then sends the second feedback information to the first UE.

For example, the second UE may simultaneously transmit the first feedback information and the second feedback information to the first UE and transmit the second feedback information to a serving base station of the second UE. Alternatively, the second UE may first send the first feedback information to the first UE, and then send the second feedback information to the serving base stations of the first UE and the second UE at the same time. Alternatively, the second UE may first send the first feedback information and the second feedback information to the first UE, and then send the second feedback information to the serving base station of the second UE. The embodiment of the present invention is not limited thereto.

For example, the second UE may send the first feedback information to the first UE while sending the second feedback information to the serving base station of the second UE. Alternatively, the second UE may first send the first feedback information to the first UE, and then send the second feedback information to the serving base station of the second UE. In this way, the first UE can determine whether the last data transmission is correct or not in a short time to determine whether the transmitted data packet needs to be retransmitted or not. This can guarantee the latency of the D2D link.

In this way, the second UE sends the first feedback information to the first UE via the D2D link in time, which at least guarantees the operation of the D2D link. However, if the D2D link is problematic, for example, if a larger loss occurs due to the blockage of the transmission path, the first UE may not be able to overcome the loss after receiving the first feedback information. At this time, if the first UE changes the transmission power as needed, unnecessary negative effects may be caused on other links, and how much the transmission power is changed should not be completely decided by the first UE. On the other hand, if the size of the data packet to be transmitted is fixed, if the MCS level is lowered, it means that more time-frequency resources need to be used. The network fully considers the communication requirements of other cellular links and other D2D links when allocating time-frequency resources to the D2D link. At this time, if the first UE arbitrarily expands the time-frequency resources used by itself, it is likely to occupy the resources allocated to other UEs, so that not only the reliability of the D2D link cannot be improved, but also co-channel interference between other UEs is generated on the occupied resources, resulting in degraded performance of both the first UE and other UEs. Therefore, when the first UE needs to adjust MCS, transmit power and time-frequency resources, the serving base station of the first UE configures the first UE appropriately according to the obtained second feedback information and scheduling information of other users, so as to ensure effective operation of the entire system.

It can be appreciated that if the first UE and the second UE are located within the same cell, the serving base station of the first UE and the serving base station of the second UE are the same base station. If the first UE and the second UE are located in different cells, the serving base station of the second UE needs to send the second feedback information received from the second UE to the serving base station of the first UE through inter-base station signaling, so that the serving base station of the first UE schedules and configures the D2D link.

Optionally, the receiving unit 301 may further receive Scheduling Assignment (SA) indication information sent by the first UE. Wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: MCS, transmit power and time-frequency resources. In this way, the processing unit 302 may receive the transmission signal sent by the first UE according to the SA indication information.

Alternatively, the processing unit 302 may generate a second reference signal according to the received transmission signal, and the transmitting unit 303 may transmit the second reference signal to the first UE. Or, optionally, the first feedback information generated by the processing unit 302 comprises a second reference signal. Wherein the second reference signal is determined according to a predefined sequence. The second reference signal may also be referred to as a sequence reference signal.

Thus, the processing unit 302 may perform estimation according to the received second reference signal and obtain channel quality information of the D2D link.

Here, the second reference signal is generated by placing a sequence on a corresponding time-frequency resource. The sequence may be a pseudo-random sequence, or may be a perfect sequence, or may be a low zero correlation zone sequence. The embodiment of the present invention is not limited thereto.

For example, the sequence may be an m-sequence or a Gold sequence, or may be a ZC (Zadoff-Chu) sequence, or may be a DeModulation Reference Signal (DMRS) sequence used in the LTE uplink.

The sequences used by the DMRS therein may be generated from predefined sequences and ZC sequences. Sequence of stepsColumn passing through ZC sequence x_qThe cyclic shift of (a) is generated as follows:

wherein, the length of the DMRS sequence is shown, wherein the ZC sequence q shows a root sequence number and is the length of the ZC sequence. When the sequence length is one or 2 times the length of a Physical Resource Block (PRB), the sequence used by DMRS is predefined, i.e.:

where a phase vector is represented and the values are predefined by a table.

After the generation, a cyclic shifted sequence corresponding to the DMRS may be further generated as follows:

where the cyclic shift value is indicated.

It can be seen that to generate a ZC sequence, the cyclic shift value α of the sequence length sequence, the root sequence number q of the sequence, and the Orthogonal Cover mask (OCC) used by the sequence are first determined.

For example, the SA includes an 8-bit ID, the second UE can use all or part of the 8 bits to calculate a root sequence number q or a cyclic shift value α of the sequence, the cyclic shift value α can be indicated by (e.g., some 3 bits of) some bits of the ID in the SA, the value of the OCC can be indicated by (e.g., some 3 bits of) some bits of the ID in the SA, and the root sequence number q of the sequence is indicated by (e.g., some bits of) some bits of the ID in the SA.

Wherein the first UE may transmit the transmission resource to the second UE through an SA control Channel, or through a Physical D2D Synchronization Channel (PD 2DSCH), or through a data Channel. For example, the first UE may send the transmission resources to the second UE by sending SA indication information.

For example, the processing unit 302 may calculate the position of a radio frame or a subframe occupied in the time domain included in the feedback resource. It may be the time domain location of the nearest D2D feedback resource after receiving the transmission resource and after a certain time threshold (e.g. 4 ms). For example, when the currently transmitted data packet is received in the 3 rd subframe in the current radio frame, the subframe 6 and the subframe 8 both have the feedback resource nearest to the currently transmitted data packet, but the interval between the subframe 6 and the subframe 3 is less than the threshold 4ms, so the subframe 8 is selected as the time domain position of the feedback resource.

As another example, the receiving unit 301 may receive the feedback resource transmitted by the first UE. Wherein the feedback resource is determined by the first UE according to a transmission resource and from association information indicating an association between the transmission resource and the feedback resource. It is appreciated that the transmission resources and associated information may be received by the first UE from a serving base station of the first UE; alternatively, the transmission resources and association information may be pre-configured on the first UE; alternatively, the transmission resource may be received by the first UE from a serving base station of the first UE and the association information is pre-configured on the first UE.

Therefore, the embodiment of the invention associates the feedback resource with the emission resource through the association information, and can reduce the signaling overhead.

It should be noted that if the first UE and the second UE are located in the same cell, the serving base station of the first UE and the serving base station of the second UE are the same base station. If the first UE and the second UE are located in different cells, the serving base station of the first UE and the serving base station of the second UE are two different base stations, and communication between the serving base station of the first UE and the serving base station of the second UE can be performed through signaling between the base stations.

Fig. 4 is a block diagram of a user equipment according to another embodiment of the present invention. UE 400 shown in fig. 4 is a first UE and includes a processing unit 401, a transmitting unit 402, and a receiving unit 403.

A processing unit 401 for generating a transmission signal;

a sending unit 402, configured to send the transmission signal generated by the processing unit 401 to a second UE, where the transmission signal is transmitted through a D2D link between the first UE and the second UE;

a receiving unit 403, configured to receive the first feedback information sent by the second UE.

In the embodiment of the invention, after the first UE sends the transmission signal to the second UE, the first UE can receive the first feedback information of the second UE. So that the reception quality of the second UE can be obtained, and the QoS of the D2D communication can be guaranteed.

It is understood that the receiving unit 403 receives the first feedback information sent by the second UE through the D2D link.

Alternatively, the processor may, as an embodiment,

the transmit signal generated by processing unit 401 may be a first reference signal and the first reference signal is used to make quality measurements for the D2D link. Then the first feedback information received by the receiving unit 403 may comprise signal quality information and/or transmit power information of the D2D link.

Wherein the signal quality information may include at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI. The transmission power information may include a value of transmission power and/or adjustment information of transmission power.

In this way, the processing unit 401 may obtain channel quality information of the D2D link between the first UE and the second UE according to the first feedback information. Further, the processing unit 401 may adjust the configuration parameters according to the first feedback information, and the first UE may send the data packet to the second UE.

Optionally, the sending unit 402 may send the transmission signal to the second UE according to a transmission resource.

As an example, the receiving unit 403 may receive second configuration information sent by a serving base station of the first UE, where the second configuration information includes indication information, and the indication information is used to indicate a location of the transmission resource; the first UE determines the transmission resource according to the second configuration information.

It is understood that the serving base station of the first UE may send the second configuration information to the first UE through signaling. The signaling may be common signaling, such as a System Information Block (SIB). Alternatively, the signaling may be Radio Resource Control (RRC) signaling common to the cells. Alternatively, the signaling may be a dedicated signaling sent to the first UE, such as Downlink Control Information (DCI) signaling. Alternatively, the signaling may be dedicated RRC signaling. The invention is not limited in this regard.

As another example, the receiving unit 403 may obtain association information, and receive a feedback resource sent by the second UE, and further, the processing unit 401 may determine the transmission resource according to the association information and the feedback resource. Wherein the association information is used for indicating an association relationship between the transmission resources and the feedback resources, and the association information may be predefined or received from a serving base station of the first UE.

It is understood that the association information may be preconfigured on the first UE or the serving base station of the first UE may send the association information to the first UE through signaling.

It is understood that the feedback resource pool may be preconfigured on the second UE, or the serving base station of the second UE may configure the feedback resource pool for the unicast link to the second UE through signaling. In this way, the second UE may select a transmission resource from the pool of feedback resources. Here, the feedback resource pool is a set of feedback resources.

As another example, the receiving unit 403 may receive the transmission resource sent by the second UE, where the transmission resource is determined by the second UE according to a feedback resource and association information, and the association information is used to indicate an association relationship between the transmission resource and the feedback resource.

It is understood that the feedback resources and associated information may be received by the second UE from a serving base station of the second UE; alternatively, the feedback resources and the association information may be pre-configured on the second UE; alternatively, the feedback resource may be received by the second UE from a serving base station of the second UE, and the association information is pre-configured on the second UE.

It is to be appreciated that the feedback resource pool and the association information can be preconfigured on the second UE. Alternatively, the association information may be preconfigured on the second UE, and the serving base station of the second UE configures the feedback resource pool for the unicast link to the second UE through signaling. Alternatively, the serving base station of the second UE may configure the feedback resource pool and the association information for the unicast link to the second UE through signaling. In this way, the second UE may select a feedback resource from the feedback resource pool and determine a transmission resource based on the feedback resource and the association information.

As another example, the transmission resource is autonomously selected by the first UE from a pool of transmission resources, wherein the feedback resource pool is pre-configured or received from a serving base station of the first UE.

It is to be appreciated that a pool of transmit resources can be preconfigured on the first UE. Or the serving base station of the first UE may configure the first UE with a pool of transmission resources for the unicast link through signaling. Here, the transmission resource pool is a set of transmission resources.

Optionally, the receiving unit 403 may obtain association information, where the association information is used to indicate an association relationship between the transmission resource and a feedback resource, and the association information is predefined or received from a serving base station of the first UE; the processing unit 401 determines a feedback resource according to the association information and the transmission resource.

In this way, the receiving unit 403 may receive the first feedback information sent by the second UE according to the feedback resource.

Alternatively, as another embodiment,

the transmission information generated by the processing unit 401 may be a data packet. Then, the first feedback information received by the receiving unit 403 may include the response information demodulated by the second UE from the data packet. Wherein, the response information is Acknowledgement information (ACK) with correct demodulation or Negative Acknowledgement information (NACK) with wrong demodulation.

Optionally, the first feedback information may further include signal quality information and/or transmission power information of the D2D link. Or, optionally, the receiving unit 403 may further receive second feedback information sent by the second UE, where the second feedback information includes signal quality information and/or transmission power information of the D2D link.

It is understood that the receiving unit 403 may receive the second feedback information transmitted by the second UE through the D2D link.

And when the data packet transmitted by the first UE is a data packet in a PD2DSCH channel, the signal quality information may be determined by the second UE based on a DMRS in the PD2DSCH or may be determined based on a D2DSS transmitted together with the PD2 DSCH. And further, the data packet may be one or more of: SA, data corresponding to the data packet, and data packet included in PD2 DSCH.

Optionally, the data packet sent by the sending unit 402 to the second UE may include the first indication information. Wherein the first indication information is used for indicating at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link. Thus, the second UE may know from the data packets received from the first UE who the first UE is, and/or who its target UE is, and/or which of the target D2D links is.

Optionally, the first feedback information may further include a second reference signal, wherein the second reference signal is determined according to a predefined sequence.

Optionally, the receiving unit 403 may further receive a second reference signal transmitted by the second UE, where the second reference signal is determined according to a predefined sequence.

The sequence may be a pseudo-random sequence, or may be a perfect sequence, or may be a low zero correlation zone sequence. The embodiment of the present invention is not limited thereto. For the description of the sequence, reference may be made to the description of the sequence in the foregoing embodiment of fig. 3, and in order to avoid repetition, the description is omitted here.

Thus, the processing unit 401 may perform estimation according to the second reference signal and obtain channel quality information of the D2D link.

For example, the processing unit 401 may perform the estimation by using a path loss calculation method. The processing unit 401 can calculate the transmission power of the second UE by the difference dP between the transmission powers of the second UE and the first UE, then the first UE estimates the power of the received signal on the sequence sent by the second UE, and then can calculate the path loss from the second UE to the first UE: and L is Pue 2-Prx. After obtaining the path loss, the first UE can determine whether the current transmit power is appropriate; or how much SNR is available at the current transmit power so that the first UE can select the appropriate transmit power or MCS value according to the path loss.

For example, the processing unit 401 may estimate the Signal to Interference plus Noise Ratio (SINR) by using an SINR estimation algorithm. The first UE estimates an equivalent SINR on a sequence sent by the second UE, and then obtains an equivalent transmit power of a signal from the first UE that the second UE can receive, by using a difference dP between transmit powers of the second UE and the first UE: SNRue2 ═ SNR-dP. After the first UE estimates the equivalent transmitting power, whether the transmitting power needs to be adjusted or not can be determined; or whether to adjust the MCS and how to adjust the MCS without adjusting the transmission power.

As an example, the receiving unit 403 may receive second configuration information sent by a serving base station of the first UE, where the second configuration information includes indication information, and the indication information is used to indicate a location of the transmission resource; the processing unit 401 determines the transmission resource according to the second configuration information.

Optionally, the receiving unit 403 may obtain association information, where the association information is used to indicate an association relationship between the transmission resource and a feedback resource, and the association information is predefined or received from a serving base station of the first UE; the processing unit 401 may determine a feedback resource according to the association information and the transmission resource.

Optionally, the sending unit 402 may send SA indication information to the second UE, so that the second UE receives the transmission signal according to the SA indication information. Wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: MCS, transmit power and time-frequency resources.

Further, the processing unit 401 may determine how to transmit the subsequent data packet according to the first feedback information received by the receiving unit 403.

Specifically, the method for the first UE to send the subsequent data packet may be as follows:

1) if the first feedback information includes an ACK.

As an example, the processing unit 401 may send the data packet to be sent to the second UE according to the current configuration parameter. That is, the first UE still transmits the next data packet using the radio link configuration parameters of the last successful transmission, which include one or more of the following: MCS, transmitting power, retransmission times and resource quantity. The method has the advantages that: since the last configuration parameter may result in a successful transmission, it is anticipated that the sending of the next packet may be successfully achieved with a high probability using the same configuration parameters.

As another example, the processing unit 401 may suspend an untransmitted retransmission packet of a transmitted data packet, and transmit a new data packet to be transmitted to the second UE according to the current configuration parameters. If the time when the first UE receives the first feedback information is earlier than the time when the next retransmission of the current data packet is sent, the first UE may terminate the sending of the subsequent retransmission packet and directly start the sending of the new data packet. At this time, the first UE needs to indicate to the second UE that the transmission is a new data packet, rather than a retransmission of a previous data packet.

Thus, the unnecessary retransmission times can be reduced, and the utilization rate of the frequency spectrum can be improved.

As another example, if the first UE confirms reception of the signal quality information transmitted by the second UE after receiving the ACK. Wherein the signal quality information may be included in the first feedback information or may be included in the second feedback information. It should be noted that the present embodiment does not limit the time when the first UE receives the ACK and the signal quality information. For example, the signal quality information may be received before or after the ACK is received, or the ACK and the signal quality information may be received simultaneously. Then, the processing unit 401 may adjust configuration parameters according to the signal quality information and/or the transmission power information; and the sending unit 402 sends the data packet to be sent to the second UE according to the adjusted configuration parameter.

For example, if the received signal quality information indicates that the last successfully transmitted packet has a higher CQI or a margin of transmit power, the first UE may correspondingly decrease the transmit power used in the transmission of the next packet. Wherein, the reduced transmission power value may be: a reduced transmission power value obtained according to the signal quality information; or, reducing the transmission power value by a predefined step; or the transmission power value is reduced by a step size configured by the network. The invention is not limited in this regard. But the reduced transmit power value cannot exceed the lower limit of the allowed transmit power. This lower limit may be implemented based on the first UE, or may be configured by the network through signaling. And when the reduced transmission power value is lower than the lower limit value, the first UE transmits by adopting the power specified by the lower limit value. Therefore, redundant power can be timely reduced, so that co-channel interference in the whole network is reduced, and the efficiency of the system can be improved.

For example, if the first UE determines that the MCS used by the last successfully transmitted data packet is lower than the CQI indicated by the signal quality information or that the transmission power has a certain margin, the first UE may use a smaller number of retransmissions or a retransmission template corresponding to the smaller number of retransmissions to transmit the subsequent data packet to be transmitted. In this way, the first UE adjusts the number of retransmissions according to the received signal quality information, which can improve the spectrum efficiency of the system.

For example, if the received signal quality information indicates that the last successfully transmitted packet has a higher CQI or a margin of transmit power, the first UE may use a higher MCS level and may also use less time-frequency resources if the size of the packet to be transmitted is not changed. Therefore, the first UE adjusts the MCS level according to the received signal quality information, or uses less time-frequency resources to send subsequent data packets, and the co-frequency interference can be reduced.

2) If the first feedback information comprises a NACK.

As an example, if the retransmission packet of the transmitted data packet has not been transmitted, the processing unit 401 may transmit the retransmission packet of the transmitted data packet to the second UE according to the current configuration parameter. That is, after receiving the NACK, the first UE continues to attempt retransmission of the data packet without changing the current configuration parameters.

As another example, if the first UE confirms reception of the signal quality information transmitted by the second UE after receiving NACK. Wherein the signal quality information may be included in the first feedback information or may be included in the second feedback information. It should be noted that the present embodiment does not limit the time when the first UE receives the ACK and the signal quality information. For example, the signal quality information may be received before or after the ACK is received, or the ACK and the signal quality information may be received simultaneously. Then, the processing unit 401 may adjust the configuration parameter according to the signal quality information and/or the transmission power information, and then perform transmission.

Specifically, if the retransmission packet of the sent data packet has not been sent, the processing unit 401 may adjust the configuration parameter according to the signal quality information and/or the transmission power information; the sending unit 402 may send the retransmission packet of the sent data packet to the second UE according to the adjusted configuration parameter.

As another example, if the retransmission packet of the transmitted data packet has been transmitted, the processing unit 401 may increase the retransmission number of the transmitted data packet or change the retransmission pattern, and the transmitting unit 402 transmits the retransmission packet of the transmitted data packet to the second UE.

Thus, if the retransmission times of the transmitted data packet have ended, the first UE may successfully transmit the data packet by increasing the retransmission times or changing the retransmission pattern. No other configuration parameters such as transmission power need to be changed.

Further, after the transmitted data packet is successfully transmitted, a larger number of retransmissions or a modified retransmission pattern may be used for subsequent new data packets.

As another example, if the first UE confirms reception of the signal quality information transmitted by the second UE after receiving NACK. If the retransmission packet of the transmitted data packet has been transmitted, the processing unit 401 may adjust the configuration parameter according to the signal quality information, and perform subsequent transmission according to the adjusted configuration parameter.

For example, the first UE may calculate a difference between a currently set MCS and an actually supportable MCS according to the CQI in the received signal quality information, and then compensate for the performance gap by selecting a corresponding retransmission number, thereby ensuring normal reception. For example, if the CQI for the currently used MCS is 5, the corresponding equivalent SNR threshold is 0.71dB, but the actual SNR for the current channel included in the signal quality information is-1 dB, then the difference between the supported SNR and the actual channel is: 1-0.71-1.71 dB, i.e. the first UE needs to compensate 1.71 dB. If the retransmission number of the current data packet is 2, then at the next retransmission, the retransmission of the transmitted data packet whose retransmission number is 2 may be directly sent again. Meanwhile, the retransmission pattern may be adjusted. For example, in an Incremental Redundancy (IR) retransmission, if a version transmitted for the first time is [0, 2], a next retransmission may correspond to a version number of [3, 1 ]. This allows more coding gain to be achieved.

For example, if the signal quality information received by the first UE indicates that the last unsuccessfully transmitted data has a lower CQI or insufficient transmit power, the first UE may increase the transmit power used in the subsequent transmission of new data packets. The increased transmit power value may be: an increase power value obtained according to the signal quality information; or, increasing the transmission power value by a predefined step; or increase the transmission power value by a step size configured by the network. And the increased transmit power cannot exceed the upper limit of the allowed transmit power. This upper limit value may be implemented based on the first UE, or may be configured by the network through signaling. When the increased transmission power is higher than the upper limit value, the first UE transmits a new data packet by using the power specified by the upper limit value as the transmission power.

Therefore, the first UE can increase the transmitting power under the allowable condition without increasing additional frequency spectrum resources, and the efficiency of the system can be further improved.

For example, if the signal quality information received by the first UE indicates that the last unsuccessfully transmitted data packet has a lower CQI or a certain lack of transmit power, the first UE may use a lower MCS level and need to use more time-frequency resources for transmission if the size of the subsequent new data packet is not changed. At this time, it is not suitable to increase the retransmission times or increase the transmission power, and only by reducing the MCS level, the stability of the link is improved by using a lower equivalent code rate. That is, the first UE may use a lower MCS level to send a subsequent new data packet.

It can be understood that more time-frequency resources are used to transmit the subsequent new data packet, which can be used as an alternative method when the retransmission times are limited and the transmission power is limited.

In this way, the first UE can ensure successful transmission of subsequent data packets according to the first feedback information, or according to the first feedback information and the second feedback information, so as to improve the spectrum efficiency of the system.

In addition, the second UE may transmit the generated second feedback information to a serving base station of the second UE. The serving base station of the second UE and the serving base station of the first UE are the same base station if the first UE and the second UE are located in the same cell. If the first UE and the second UE are located in different cells, the serving base station of the second UE may send the second feedback information to the serving base station of the first UE through inter-base station signaling.

The serving base station of the first UE may schedule and configure resources of the D2D link according to the second feedback information and the communication status of the whole network.

It is to be understood that the receiving unit 403 may also receive first configuration information sent by the serving base station of the first UE, where the first configuration information includes at least one of the following: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of a used MCS, and indication information of a used time-frequency resource, wherein the first configuration information is determined by a serving base station of the first UE according to second feedback information sent by the second UE; the processing unit 401 may adjust the configuration parameter according to the first configuration information, and send the subsequent data packet to be sent to the second UE according to the adjusted configuration parameter.

Wherein the first configuration information may further include information indicating an ID of the D2D link.

In this way, the processing unit 401 may adjust the configuration parameters according to the first configuration information sent by the serving base station of the first UE, and may avoid the first UE adjusting itself from affecting other UEs and other links.

Specifically, the way for the processing unit 401 to send the subsequent data packet according to the first configuration information may be as follows:

if the first UE receives the first configuration information sent by the serving base station of the first UE, the data packets cached in the sending buffer of the first UE are not completely sent.

As an example, the processing unit 401 may use the previously used configuration parameters to complete the retransmission of the current data packet. And then the first UE adjusts the configuration parameters according to the first configuration information and sends subsequent retransmission packets or subsequent new data packets by adopting the adjusted configuration parameters.

As another example, if the first UE has received NACK sent by the second UE or the first UE does not receive the first feedback information, the processing unit 401 may adjust the configuration parameter according to the first configuration information, and send the retransmission packet of the data packet that is not successfully transmitted currently using the adjusted configuration parameter.

It should be noted that, in the embodiment of the present invention, the configuration parameter may include at least one of the following: MCS level, retransmission times, retransmission pattern information, transmission power information and indication information of time frequency resources.

Fig. 5 is a block diagram of a base station according to an embodiment of the present invention. The base station 500 shown in fig. 5 comprises a receiving unit 501, a processing unit 502 and a transmitting unit 503.

A receiving unit 501, configured to receive feedback information sent by a second UE, where the feedback information includes signal quality information and/or transmission power information of a D2D link between a first UE and the second UE.

The processing unit 502 is configured to generate first configuration information according to the feedback information received by the receiving unit 501.

A sending unit 503, configured to send the first configuration information generated by the processing unit 502 to a first UE, where the base station is a serving base station of the first UE.

In the embodiment of the invention, the base station generates the first configuration information according to the feedback information received from the second UE and sends the first configuration information to the first UE, so that the first UE can adjust the configuration parameters according to the first configuration information. In this way, not only can correct transmission of data on the D2D link between the first UE and the second UE be guaranteed, but also transmission of links of other UEs is not affected.

It is understood that if the first UE and the second UE are located in the same cell, then the base station 500 is also the serving base station for the second UE. The serving base station for the second UE is different from base station 500 if the first UE and the second UE are located in different cells. Then, the receiving unit 501 is specifically configured to receive the feedback information sent by the second UE from the serving base station of the second UE.

That is, the receiving unit 501 receives the feedback information from the serving base station of the second UE through signaling between base stations, and the feedback information is transmitted to the serving base station of the second UE by the second UE.

Optionally, the feedback information received by the receiving unit 501 includes signal quality information and/or transmission power information of a D2D link between the first UE and the second UE.

Optionally, the feedback information may further include indication information, wherein the indication information is used to indicate at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.

In this way, the base station 500 can know to which D2D link the signal quality information and/or the transmit power information in the feedback information is directed.

Optionally, the first configuration information generated by the processing unit 502 may include at least one of the following: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of Modulation and Coding Scheme (MCS) used and indication information of time-frequency resources used.

Optionally, the first configuration information may further include information indicating an ID of the D2D link.

It is to be understood that the transmitting unit 503 transmits the first configuration information to the first UE through the cellular link.

Optionally, as an embodiment, the sending unit 503 is further configured to send second configuration information to the first UE. Wherein the second configuration information comprises a transmission resource pool and/or association information for the D2D link, the association information being used for indicating an association relationship between transmission resources and feedback resources.

In this way, the first UE may send a data packet to the second UE according to the second configuration information.

Optionally, as another embodiment, if the first UE and the second UE are located in the same cell, the sending unit 503 is further configured to send third configuration information to the second UE, where the third configuration information includes a feedback resource pool and/or association information for the D2D link, and the association information is used to indicate an association relationship between transmission resources and feedback resources.

Assuming that the first UE and the second UE are located in the same cell, the sending unit 503 may send the second configuration information only to the first UE; or the sending unit 503 may send the third configuration information only to the second UE; or the sending unit 503 sends the second configuration information to the first UE and sends the third configuration information to the second UE.

For the associated information, reference may be made to the related description about the associated information in fig. 3 and fig. 4 in the foregoing embodiment, and details are not repeated here to avoid repetition.

Fig. 6 is a block diagram of a base station according to another embodiment of the present invention. The base station 600 shown in fig. 6 is a second base station and includes a receiving unit 601 and a transmitting unit 602.

A receiving unit 601, configured to receive feedback information sent by a second UE, where the feedback information includes signal quality information and/or transmission power information of a D2D link between a first UE and the second UE, and the second base station is a serving base station of the second UE.

A sending unit 602, configured to send the feedback information to a first base station, where the first base station is a serving base station of a first UE, and the first UE and the second UE are located in different cells.

In the embodiment of the present invention, when the first UE and the second UE are located in different cells, the serving base station of the second UE sends the feedback information received from the second UE to the serving base station of the first UE, so that the serving base station of the first UE can obtain the feedback information about the D2D link.

Optionally, wherein the signal quality information comprises at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI; the transmission power information includes a value of transmission power and/or adjustment information of transmission power.

It is understood that the sending unit 602 may send the feedback information to the first base station through signaling between base stations.

Optionally, the feedback information further includes indication information, where the indication information is used to indicate at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.

Optionally, the sending unit 602 may further be configured to send configuration information to the second UE. The configuration information comprises a feedback resource pool and/or association information, and the association information is used for indicating an association relationship between the transmission resources and the feedback resources.

Fig. 7 is a flow chart of a method of D2D communication according to one embodiment of the invention. The method shown in fig. 7 includes:

701, a second UE receives a transmission signal sent by a first UE, wherein the transmission signal is transmitted through a D2D link between the first UE and the second UE.

And 702, the second UE generates first feedback information according to the transmitting signal.

703, the second UE sending the first feedback information to the first UE.

It is appreciated that in 703, the second UE sends the first feedback information to the first UE over the D2D link.

Alternatively, the processor may, as an embodiment,

the transmitted signal in 701 may be a first reference signal and the first reference signal is used to make quality measurements for the D2D link. Then the first feedback information in 702 may include signal quality information and/or transmit power information for the D2D link.

The second UE may estimate the signal quality of the D2D link from the transmitted signal and generate signal quality information. Wherein the signal quality information may include at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI), and adjustment information for the CQI. The transmission power information may include a value of transmission power and/or adjustment information of transmission power.

Specifically, the second UE may prestore all supported antenna configurations and equivalent Signal-to-Noise Ratio (SNR) thresholds that can be correctly demodulated at various Modulation and Coding Scheme (MCS) levels.

For example, in the LTE system, under the condition of using Turbo coding, the equivalent SNR threshold for correctly demodulating signals with different Channel Quality Indicator (CQI) values in a transmit-receive multi-antenna configuration is shown in table one.

Watch 1

After 701, the second UE may calculate a current equivalent SNR value from the transmitted signal. And, the second UE may determine the corresponding equivalent SNR threshold from the first table according to the transmission signal.

Further, the second UE may calculate CQI, adjustment information Δ CQI of CQI, and adjustment information Δ P of transmission power according to the equivalent SNR and the equivalent SNR threshold. As such, the second UE may generate the first feedback information at 702.

For example, the MCS actually used by the first UE corresponds to an equivalent SNR threshold of 0.71dB, and then the second UE may determine that the corresponding CQI is 5 according to table one. In this way, the second UE may set the CQI to 5 as the first feedback information. That is, the second UE may feed back the actual value of the CQI.

If the current equivalent SNR value calculated by the second UE from the transmission signal is 4.01dB, the second UE may calculate the adjustment information Δ P for the transmission power-the equivalent SNR threshold-the current equivalent SNR value-0.71 dB-4.01 dB-3.70 dB. In this way, the second UE may use the calculated adjustment information Δ P of the transmission power of-3.70 dB as the first feedback information.

On the other hand, since the Δ P value needs to be a real value, the calculated Δ P needs to be quantized accordingly before transmission. Specifically, the equivalent SNR threshold corresponding to the CQI may be used for quantization. For example, the calculated Δ P-3.70 dB is closest to the SNR threshold (-5.11dB) when CQI is 2 (and needs to be larger than the SNR value corresponding to CQI 2). In this way, the second UE may use CQI of 2 as the first feedback information. That is, the second UE may feed back the quantized CQI value of the calculated Δ P. And, since the entire CQI can be quantized only by 4 bits, the amount of feedback can be greatly reduced.

Alternatively, the quantization space of Δ P may be further defined, and it is assumed that the quantization space is { -3, -2, -1, 0, 1, 2, 3}, so that 3 bits can be used for representation, and the second UE feeds back the quantized value through the closest value not exceeding the quantized value when feeding back. For example, if Δ P is calculated to be-3.70 dB, the second UE may use signaling corresponding to quantization space-3 as the first feedback information. That is, the second UE may feed back the calculated Δ P as a quantized value specified by a certain quantization space.

Alternatively, the current equivalent SNR value calculated by the second UE from the transmitted signal is 4.01dB, as shown in table one, and the CQI closest to 4.01dB and not exceeding the corresponding threshold is CQI 6. Then, the second UE may have CQI of 6 as the first feedback information. That is, the second UE may feed back the acquired value of the supportable CQI. Note that here, although 4.01dB is closer to the equivalent SNR threshold 4.61 corresponding to CQI of 7, since 4.61>4.01, CQI of 7 is not used.

Alternatively, the MCS actually used by the first UE may correspond to an equivalent SNR threshold of 0.71dB, and then the second UE may determine that the corresponding CQI is 5 according to table one. That is, the currently used CQI is 5 and the measured CQI is 6, so the adjustment information Δ CQI of the CQI is the measured CQI — the currently used CQI is 1. Then, the second UE may use Δ CQI of 1 as the first feedback information. In this way, the feedback information of the second UE uses only 2 or 3 bits, which can further reduce the signaling for feedback.

It is to be understood that the above is only an illustrative example of the second UE generating the first feedback information, and the second UE may also generate the first feedback information in other manners, which is not limited in the present invention.

It should be noted that there is a correspondence between MCS and CQI.

For example, in an LTE system, the MCS is primarily allocated to the transmitter (i.e., the first UE), and the MCS is used to indicate the following information: modulation order, index of transport block size used in transmission, retransmission version. Generally, the MCS uses 5 bits to indicate. The MCS, the allocated bandwidth and the configured parameters of the number of spatial layers may be obtained by table lookup. The MCS, because it implicitly gives the size of the transport block, is equivalent to also giving the code rate of the data that needs to be transmitted (i.e. the third column of table one). While CQI is used to indicate the modulation order, code rate actually used, and the spectral efficiency of the corresponding transmission. The CQI is mainly used by the receiver (i.e., the second UE) to implement feedback on the channel quality, and the CQI may be used to characterize the quality of an equivalent channel seen by the current receiver, i.e., the supported spectrum efficiency. Briefly, the CQI indicates a subset of all supported MCSs in the LTE system.

In this way, after receiving the first feedback information sent by the second UE, the first UE may obtain channel quality information of the D2D link between the first UE and the second UE. Further, the first UE may adjust the configuration parameters according to the first feedback information, and the first UE may send the data packet to the second UE.

Optionally, after 702, the second UE may also send the first feedback information to the serving base station of the second UE through the cellular link, so that the serving base station of the second UE acquires the channel quality information of the D2D link.

Optionally, in 703, the second UE may send the first feedback information to the first UE according to a feedback resource.

As an example, before 703, the second UE may receive configuration information sent by a serving base station of the second UE, where the configuration information includes second indication information, and the second indication information is used to indicate a location of the feedback resource; and the second UE determines the feedback resource according to the configuration information.

As another example, before 703, the second UE may obtain association information and receive the transmission resource sent by the first UE; further, the second UE may determine the feedback resource according to the association information and the transmission resource. Wherein the association information is used for indicating an association relationship between the transmission resources and the feedback resources, and the association information may be predefined or received from a serving base station of the second UE.

Further, the second UE may calculate the feedback resource based on the transmission resource and the association information.

For example, the second UE may calculate the frequency domain locations included in the feedback resources by (a × Nprb + b) mod Nm. Where Nprb is the location of the transmit resource in the frequency domain, Nm is the maximum number of feedback resources provided, and mod represents the modulo operation. Where a and b are predefined, often real numbers, such as a 1, b Nm/2; alternatively, the term "a" -1 and "b" -Nm/4.

For example, the second UE may calculate the position of a radio frame or subframe occupied in the time domain included in the feedback resource. It may be the time domain location of the nearest D2D feedback resource after receiving the transmission resource and after a certain time threshold (e.g. 4 ms). For example, when the currently transmitted data packet is received in the 3 rd subframe in the current radio frame, the subframe 6 and the subframe 8 both have the feedback resource nearest to the currently transmitted data packet, but the interval between the subframe 6 and the subframe 3 is less than the threshold 4ms, so the subframe 8 is selected as the time domain position of the feedback resource.

As another example, before 703, the second UE may receive the feedback resource sent by the first UE. Wherein the feedback resource is determined by the first UE according to a transmission resource and from association information indicating an association between the transmission resource and the feedback resource.

It is understood that prior to 703, the transmit resource pool and the association information may be preconfigured on the first UE. Alternatively, the association information may be preconfigured on the first UE and the serving base station of the first UE signals to the first UE a pool of transmission resources for the unicast link. Alternatively, the serving base station of the first UE may configure the first UE with the transmission resource pool and the association information for the unicast link through signaling. In this way, the first UE may select a transmission resource from the pool of transmission resources and determine a feedback resource based on the transmission resource and the association information.

It is appreciated that prior to 703, a feedback resource pool may be preconfigured on the second UE. Or the serving base station of the second UE may configure the feedback resource pool for the unicast link to the second UE through signaling. Here, the feedback resource pool is a set of feedback resources.

Alternatively, as another embodiment,

the transmitted signal in 701 may be a data packet. Then, the first feedback information in 702 may include acknowledgement information after the second UE demodulates the data packet. Wherein, the response information is Acknowledgement information (ACK) with correct demodulation or Negative Acknowledgement information (NACK) with wrong demodulation.

After 701, the second UE may demodulate the data packet and determine whether the demodulation is correct by decoding. If the demodulation is correct, the response information is ACK; if the demodulation is wrong, the response information is NACK.

Optionally, the first feedback information may further include signal quality information and/or transmission power information of the D2D link. Or, optionally, after 701, the second UE generates second feedback information according to the demodulation result, and sends the second feedback information to the serving base station of the first UE and/or the second UE. Wherein the second feedback information comprises signal quality information and/or transmit power information of the D2D link.

Wherein the second UE may send the second feedback information to the first UE via the D2D link, and may send the second feedback information to a serving base station of the second UE via the cellular link.

In particular, the second UE may estimate the signal quality of the D2D link from the transmitted signal and generate signal quality information.

Optionally, the data packet sent by the first UE to the second UE may include the first indication information. Wherein the first indication information is used for indicating at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link. Thus, the second UE may know from the data packets received from the first UE who the first UE is, and/or who its target UE is, and/or which of the target D2D links is.

Optionally, the second UE may send second feedback information to the serving base station of the second UE, where the second feedback information may further include the first indication information. Wherein the first indication information is used for indicating at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.

Optionally, before 701, the method may further include: the second UE receives Scheduling Assignment (SA) indication information transmitted by the first UE. Wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: MCS, transmit power and time-frequency resources. Thus, in 701, the second UE may receive the transmission signal sent by the first UE according to the SA indication information.

For example, the signal transmitted by the first UE may include SA indication information 801 and a transmission signal 802 as shown in fig. 8. Wherein, the SA indication information 801 is sent before the transmission signal 802, and the transmission signal 802 is a data packet. The SA indication information 801 is used to indicate the MCS, transmission power and time-frequency resources used for transmitting the transmission signal 802, and these information may also be included in the data packet of the SA. Thus, the second UE first receives the SA indication information 801 and receives the subsequent transmission signal 802 according to the SA indication information 801.

Optionally, the second UE may generate a second reference signal from the received transmission signal at 702, and send the second reference signal to the first UE at 703. Or, optionally, in 702, the first feedback information generated by the second UE includes a second reference signal. Wherein the second reference signal is determined according to a predefined sequence. The second reference signal may also be referred to as a sequence reference signal.

Thus, after 703, the first UE may estimate from the received second reference signal and obtain channel quality information for the D2D link.

The sequences used by the DMRS therein may be generated from predefined sequences and ZC sequences. The sequence passes through ZC sequence x_qThe cyclic shift of (a) is generated as follows:

where a phase vector is represented and the values are predefined by a table.

where the cyclic shift value is indicated.

As another example, before 703, the second UE may receive the feedback resource sent by the first UE. Wherein the feedback resource is determined by the first UE according to a transmission resource and from association information indicating an association between the transmission resource and the feedback resource. It is appreciated that the transmission resources and associated information may be received by the first UE from a serving base station of the first UE; alternatively, the transmission resources and association information may be pre-configured on the first UE; alternatively, the transmission resource may be received by the first UE from a serving base station of the first UE and the association information is pre-configured on the first UE.

It should be noted that the method illustrated in fig. 7 may be performed by the user equipment 300 illustrated in the embodiment of fig. 3 described above.

Fig. 9 is a flow chart of a method of D2D communication according to another embodiment of the invention. The method shown in fig. 9 includes:

901, a first UE generates a transmit signal.

And 902, the first UE sending the transmission signal to a second UE, wherein the transmission signal is transmitted through a D2D link between the first UE and the second UE.

903, the first UE receives the first feedback information sent by the second UE.

It may be appreciated that, in 903, the first UE receives the first feedback information sent by the second UE over the D2D link.

Alternatively, the processor may, as an embodiment,

the transmitted signal in 901 may be a first reference signal and the first reference signal is used to make quality measurements for the D2D link. Then the first feedback information in 903 may comprise signal quality information and/or transmit power information for the D2D link.

Thus, 903 later, the first UE may obtain channel quality information of the D2D link between the first UE and the second UE according to the first feedback information. Further, the first UE may adjust the configuration parameters according to the first feedback information, and the first UE may send the data packet to the second UE.

Optionally, in 902, the first UE may send the transmission signal to the second UE according to a transmission resource.

As an example, before 902, the first UE may receive second configuration information sent by a serving base station of the first UE, where the second configuration information includes indication information, and the indication information is used to indicate a location of the transmission resource; the first UE determines the transmission resource according to the second configuration information.

As another example, before 902, the first UE may obtain association information and receive a feedback resource sent by the second UE, and further, the first UE may determine the transmission resource according to the association information and the feedback resource. Wherein the association information is used for indicating an association relationship between the transmission resources and the feedback resources, and the association information may be predefined or received from a serving base station of the first UE.

As another example, before 902, the first UE may receive the transmission resource sent by the second UE, where the transmission resource is determined by the second UE according to a feedback resource and association information, and the association information is used to indicate an association relationship between the transmission resource and the feedback resource.

It is appreciated that prior to 902, a feedback resource pool and association information can be preconfigured on the second UE. Alternatively, the association information may be preconfigured on the second UE, and the serving base station of the second UE configures the feedback resource pool for the unicast link to the second UE through signaling. Alternatively, the serving base station of the second UE may configure the feedback resource pool and the association information for the unicast link to the second UE through signaling. In this way, the second UE may select a feedback resource from the feedback resource pool and determine a transmission resource based on the feedback resource and the association information.

It is appreciated that prior to 902, a transmit resource pool can be preconfigured on the first UE. Or the serving base station of the first UE may configure the first UE with a pool of transmission resources for the unicast link through signaling. Here, the transmission resource pool is a set of transmission resources.

Optionally, before 903, the method may further include: the first UE may obtain association information, wherein the association information is used to indicate an association relationship between the transmission resource and a feedback resource, and the association information is predefined or received from a serving base station of the first UE; and the first UE determines a feedback resource according to the association information and the transmitting resource.

Thus, in 903, the first UE may receive the first feedback information sent by the second UE according to the feedback resource.

Alternatively, as another embodiment,

the transmitted information in 901 may be a data packet. Then the first feedback information in 903 may comprise the acknowledgement information after the second UE demodulates the data packet. Wherein, the response information is Acknowledgement information (ACK) with correct demodulation or Negative Acknowledgement information (NACK) with wrong demodulation.

Optionally, the first feedback information may further include signal quality information and/or transmission power information of the D2D link. Or, optionally, after 902, may further include: and the first UE receives second feedback information sent by the second UE, wherein the second feedback information comprises signal quality information and/or transmission power information of the D2D link.

It is understood that the first UE may receive the second feedback information sent by the second UE over the D2D link.

Optionally, after 902, the method may further include: the first UE receives a second reference signal transmitted by the second UE, wherein the second reference signal is determined according to a predefined sequence.

The sequence may be a pseudo-random sequence, or may be a perfect sequence, or may be a low zero correlation zone sequence. The embodiment of the present invention is not limited thereto. For the description of the sequence, reference may be made to the description of the sequence in the foregoing embodiment of fig. 7, and in order to avoid repetition, the description is omitted here.

Thus, after receiving the second reference signal, the first UE may perform estimation according to the second reference signal and obtain channel quality information of the D2D link.

For example, the first UE may estimate using a path loss calculation. The first UE can calculate the transmission power of the second UE by the difference dP between the transmission powers of the second UE and the first UE, then the first UE estimates the power of the received signal on the sequence sent by the second UE, and then can calculate the path loss from the second UE to the first UE: and L is Pue 2-Prx. After obtaining the path loss, the first UE can determine whether the current transmit power is appropriate; or how much SNR is available at the current transmit power so that the first UE can select the appropriate transmit power or MCS value according to the path loss.

For example, the first UE may estimate using an equivalent Signal to Interference plus Noise Ratio (SINR) estimation algorithm. The first UE estimates an equivalent SINR on a sequence sent by the second UE, and then obtains an equivalent transmit power of a signal from the first UE that the second UE can receive, by using a difference dP between transmit powers of the second UE and the first UE: SNRue2 ═ SNR-dP. After the first UE estimates the equivalent transmitting power, whether the transmitting power needs to be adjusted or not can be determined; or whether to adjust the MCS and how to adjust the MCS without adjusting the transmission power.

Optionally, before 902, the method may further include: and the first UE sends SA indication information to the second UE so that the second UE receives the transmitting signal according to the SA indication information. Wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: MCS, transmit power and time-frequency resources.

After 903, the first UE may determine how to transmit the subsequent data packet according to the first feedback information.

Specifically, after 903, the method for the first UE to send a subsequent data packet may be as follows: 1) if the first feedback information includes an ACK.

As an example, the first UE may send a data packet to be sent to the second UE according to the current configuration parameter. That is, the first UE still transmits the next data packet using the radio link configuration parameters of the last successful transmission, which include one or more of the following: MCS, transmitting power, retransmission times and resource quantity. The method has the advantages that: since the last configuration parameter may result in a successful transmission, it is anticipated that the sending of the next packet may be successfully achieved with a high probability using the same configuration parameters.

As another example, the first UE may suspend an untransmitted retransmission packet of a transmitted data packet, and transmit a new data packet to be transmitted to the second UE according to the current configuration parameters. If the time when the first UE receives the first feedback information is earlier than the time when the next retransmission of the current data packet is sent, the first UE may terminate the sending of the subsequent retransmission packet and directly start the sending of the new data packet. At this time, the first UE needs to indicate to the second UE that the transmission is a new data packet, rather than a retransmission of a previous data packet.

Such as may be shown in fig. 10. The first UE receives the first feedback information 1002 for the second UE after sending the first transmission 1001 of the data packet, and the first feedback information includes an ACK. Then, the first UE terminates the second transmission 1003 of the originally scheduled data packet, that is, the first UE discards the retransmitted data packet, and directly performs the subsequent first transmission 1004 of a new data packet.

As another example, if the first UE confirms reception of the signal quality information transmitted by the second UE after receiving the ACK. Wherein the signal quality information may be included in the first feedback information or may be included in the second feedback information. It should be noted that the present embodiment does not limit the time when the first UE receives the ACK and the signal quality information. For example, the signal quality information may be received before or after the ACK is received, or the ACK and the signal quality information may be received simultaneously. Then, the first UE adjusts configuration parameters according to the signal quality information and/or the transmission power information; and the first UE sends the data packet to be sent to the second UE according to the adjusted configuration parameters.

2) If the first feedback information comprises a NACK.

As an example, if the retransmission packet of the transmitted data packet is not transmitted, the first UE transmits the retransmission packet of the transmitted data packet to the second UE according to the current configuration parameter. That is, after receiving the NACK, the first UE continues to attempt retransmission of the data packet without changing the current configuration parameters.

As another example, if the first UE confirms reception of the signal quality information transmitted by the second UE after receiving NACK. Wherein the signal quality information may be included in the first feedback information or may be included in the second feedback information. It should be noted that the present embodiment does not limit the time when the first UE receives the ACK and the signal quality information. For example, the signal quality information may be received before or after the ACK is received, or the ACK and the signal quality information may be received simultaneously. Then, the first UE may adjust the configuration parameter according to the signal quality information and/or the transmission power information, and then perform transmission.

Specifically, if the retransmission packet of the transmitted data packet is not yet transmitted, the first UE adjusts a configuration parameter according to the signal quality information and/or the transmission power information; and the first UE sends the retransmission packet of the sent data packet to the second UE according to the adjusted configuration parameters.

As another example, if a retransmission packet of a transmitted data packet has been transmitted, the first UE may increase the number of retransmissions of the transmitted data packet or change a retransmission pattern, and transmit the retransmission packet of the transmitted data packet to the second UE.

As another example, if the first UE confirms reception of the signal quality information transmitted by the second UE after receiving NACK. If the retransmission packet of the transmitted data packet is already transmitted, the first UE may adjust the configuration parameter according to the signal quality information, and perform subsequent transmission according to the adjusted configuration parameter.

In this way, after 903, the first UE may ensure successful transmission of the subsequent data packet according to the first feedback information, or according to the first feedback information and the second feedback information, so as to improve the spectrum efficiency of the system.

It is understood that after 903, the following may be included: the first UE receives first configuration information sent by a serving base station of the first UE, wherein the first configuration information comprises at least one of the following: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of a used MCS, and indication information of a used time-frequency resource, wherein the first configuration information is determined by a serving base station of the first UE according to second feedback information sent by the second UE; and the first UE adjusts configuration parameters according to the first configuration information and sends subsequent data packets to be sent to the second UE according to the adjusted configuration parameters.

In this way, the first UE may adjust the configuration parameters according to the first configuration information sent by the serving base station of the first UE, and may avoid the influence on other UEs and other links caused by the first UE adjusting itself.

Specifically, the manner in which the first UE sends the subsequent data packet according to the first configuration information may be as follows:

As an example, the first UE may complete retransmission of the current data packet using previously employed configuration parameters. And then the first UE adjusts the configuration parameters according to the first configuration information and sends subsequent retransmission packets or subsequent new data packets by adopting the adjusted configuration parameters.

For example, as shown in fig. 11. The first UE receives first feedback information 1102 from the second UE after sending a first transmission 1101 of a data packet, after which first configuration information 1103 sent from the serving base station of the first UE is received. However, the first UE still sends the second transmission of data packets 1104 according to the previous configuration parameters and continues to receive the first feedback information 1105 sent by the second UE. And after 1105, the first UE adjusts the configuration parameters according to the first configuration information 1103. That is, the first configuration information does not begin to take effect until after 1105. After 1105, the first UE transmits 1106 a new configuration, where the new configuration refers to the configuration parameters adjusted according to the first configuration information 1103.

As another example, if the first UE has received NACK sent by the second UE or the first UE does not receive the first feedback information, the first UE may adjust the configuration parameter according to the first configuration information, and send the retransmission packet of the data packet that is not successfully transmitted currently using the adjusted configuration parameter.

For example, as shown in fig. 12. The first UE receives the first feedback information 1202 from the second UE after sending the first transmission 1201 of the data packet, after which the first configuration information 1203 sent from the serving base station of the first UE is received. Then the first UE adjusts the configuration parameters according to the first configuration information 1103. And, after 1203, transmit 1204 in the new configuration. Here, the new configuration refers to the configuration parameters adjusted according to the first configuration information 1203.

At this time, if the first UE has received the ACK sent by the second UE, the first UE may adjust the configuration parameter according to the first configuration information, and send a subsequent new data packet by using the adjusted configuration parameter.

It should be noted that the method illustrated in fig. 9 may be performed by the user equipment 400 illustrated in the embodiment of fig. 4 described above.

Fig. 13 is a flow chart of a method for D2D communication according to another embodiment of the invention. The method shown in fig. 13 includes:

1301, the base station receives feedback information sent by a second User Equipment (UE), wherein the feedback information includes signal quality information and/or transmission power information of a D2D link between the first UE and the second UE.

1302, the base station generates first configuration information according to the feedback information.

1303, the base station sends the first configuration information to a first UE, where the base station is a serving base station of the first UE.

It can be appreciated that if the first UE and the second UE are located in the same cell, then the base station in fig. 13 is also the serving base station for the second UE. The serving base station for the second UE is different from the base station in fig. 13 if the first UE and the second UE are located in different cells. Then 1301 may include: and receiving feedback information sent by the second UE from a serving base station of the second UE.

That is, the base station receives the feedback information from the serving base station of the second UE through signaling between base stations, and the feedback information is transmitted to the serving base station of the second UE by the second UE.

Optionally, the feedback information in 1301 includes signal quality information and/or transmit power information of the D2D link between the first UE and the second UE.

Optionally, the feedback information in 1301 may further include indication information, where the indication information is used to indicate at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.

In this way, the base station can know to which D2D link the signal quality information and/or transmit power information in the feedback information is directed.

Optionally, the first configuration information in 1302 may include at least one of: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of Modulation and Coding Scheme (MCS) used and indication information of time-frequency resources used.

Optionally, the first configuration information in 1302 may further include information indicating an ID of the D2D link.

It is understood that 1303, the base station transmits the first configuration information to the first UE through the cellular link.

Optionally, as an embodiment, the method may further include: and the base station sends second configuration information to the first UE. Wherein the second configuration information comprises a transmission resource pool and/or association information for the D2D link, the association information being used for indicating an association relationship between transmission resources and feedback resources.

Optionally, as another embodiment, if the first UE and the second UE are located in the same cell, the method may further include: the base station sends third configuration information to the second UE, where the third configuration information includes a feedback resource pool for the D2D link and/or association information, and the association information is used to indicate an association relationship between transmission resources and feedback resources.

The base station may send the second configuration information only to the first UE, assuming that the first UE and the second UE are located in the same cell; or the base station may send the third configuration information only to the second UE; or the base station sends the second configuration information to the first UE and sends the third configuration information to the second UE.

For the associated information, reference may be made to the related description about the associated information in fig. 7 and fig. 9 in the foregoing embodiment, and details are not repeated here to avoid repetition.

It should be noted that the method illustrated in fig. 13 may be performed by the base station 500 illustrated in the embodiment of fig. 5 described above.

Fig. 14 is a flow chart of a method for D2D communication according to another embodiment of the invention. The method shown in fig. 14 includes:

1401, the second base station receives feedback information sent by a second UE, wherein the feedback information includes signal quality information and/or transmission power information of a D2D link between a first UE and the second UE, and the second base station is a serving base station of the second UE.

1402, the second base station sends the feedback information to a first base station, the first base station is a serving base station of a first UE, and the first UE and the second UE are located in different cells.

It is understood that 1402 the second base station sends the feedback information to the first base station through signaling between base stations.

Optionally, the method shown in fig. 14 may further include: and the second base station sends configuration information to the second UE. The configuration information comprises a feedback resource pool and/or association information, and the association information is used for indicating an association relationship between the transmission resources and the feedback resources.

It should be noted that the method illustrated in fig. 14 may be performed by the base station 600 illustrated in the embodiment of fig. 6 described above.

For a more intuitive understanding of the embodiments of the present invention, fig. 15 to 18 show signaling flowcharts of D2D communication according to the embodiments of the present invention. It should be noted that, for the detailed description of the method in fig. 15 to fig. 18, reference may be made to the related description in the foregoing embodiment of fig. 1 to fig. 14, and in order to avoid repetition, the detailed description is not repeated here.

Fig. 15 is a signaling flow diagram of D2D communication according to one embodiment of the invention. The method shown in fig. 15 includes:

1501, the first UE 151 generates a transmission signal.

1502, the first UE 151 sends a transmission signal to the second UE 152.

It is understood that the first UE 151 sends the transmission signal to the second UE152 over the D2D link between the first UE 151 and the second UE 152.

1503, the second UE152 generates the first feedback information.

1504, the second UE152 sends the first feedback information to the first UE 151.

Optionally, as an embodiment, the transmission signal may be a first reference signal. Accordingly, the first feedback information includes signal quality information and/or transmit power information of the D2D link.

Alternatively, as another embodiment, the transmission signal may be a data packet. Accordingly, the first feedback information includes the response information of the second UE152 after demodulating the data packet. Wherein the response information is ACK or NACK.

Wherein the data packet may include the DMRS. Optionally, the data packet may further include first indication information. Wherein the first indication information is used for indicating at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.

Further, the first feedback information may also include signal quality information and/or transmit power information of the D2D link.

Or, further, the first feedback information may further include a second reference signal. Wherein the second reference signal is determined by a predefined sequence.

Wherein 1501 in fig. 15 can be referred to as 901 in the foregoing fig. 9 embodiment, and 1502 in fig. 15 can be referred to as 902 in the foregoing fig. 9 embodiment; 1503 in fig. 15 may refer to 702 in the foregoing embodiment in fig. 7, and 1504 in fig. 15 may refer to 703 in the foregoing embodiment in fig. 7, which are not repeated here to avoid repetition.

Further, if the transmission signal generated in 1501 is a data packet, as shown in fig. 16, the method may further include:

1505, the second UE152 generates second feedback information.

1506, the second UE152 sends the second feedback information to the serving base station 153 of the second UE.

Optionally, it can also include

1507, the second UE152 transmits the second feedback information to the first UE 151.

Wherein the second feedback information comprises signal quality information and/or transmission power information of the D2D link.

Optionally, the second feedback information in 1506 may further include the first indication information. The first indication information is used for indicating at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.

It should be noted that the sequence numbers here do not constitute a limitation on the execution order. For example, 1505 may be executed concurrently with 1503. For example, 1506 may be performed after 1505 and before 1504. The invention is not limited in this regard.

If the first UE 151 and the second UE152 are located in different cells, after the method shown in fig. 16, as shown in fig. 17, the method may further include:

1508, the serving base station 153 of the second UE sends the second feedback information to the serving base station 154 of the first UE.

It is understood that the serving base station 153 of the second UE transmits the second feedback information to the serving base station 154 of the first UE through signaling between the base stations.

1509, the serving base station 154 of the first UE generates first configuration information.

1510, the serving base station 153 of the second UE generates second configuration information.

Specifically, the serving base station 154 of the first UE and the serving base station 153 of the second UE may respectively generate the first configuration information and the second configuration information for the D2D link according to the second feedback information and according to the communication status of the whole network.

1511, the serving base station 154 of the first UE sends the first configuration information to the first UE 151.

Specifically, the serving base station 154 of the first UE transmits the first configuration information to the first UE 151 through the cellular link.

1512, the serving base station 153 of the second UE sends the second configuration information to the second UE 152.

Specifically, the serving base station 153 of the second UE transmits the second configuration information to the second UE152 through the cellular link.

Wherein 1510 and 1512 may not be performed.

Wherein the first configuration information may include a transmission resource pool and/or association information for the D2D link. The association information is used for indicating an association relationship between the transmission resources and the feedback resources.

1513, the first UE 151 adjusts the configuration parameters according to the first configuration information.

Wherein the configuration parameter may include at least one of: MCS level, retransmission times, retransmission pattern information, transmission power information and indication information of time frequency resources.

1514, the first UE 151 sends subsequent data packets to the second UE152 according to the adjusted configuration parameters.

Alternatively, the first UE 151 may send the transmission resource to the second UE152 (not shown in fig. 17) through the SA indication information, so that the second UE152 receives the subsequent data packet according to the transmission resource.

It should be noted that the sequence numbers here do not constitute a limitation on the execution order. For example, 1509 may be executed concurrently with 1510. For example, 1512 may be performed before 1511. The invention is not limited in this regard.

If the first UE 151 and the second UE152 are located in the same cell, it is understood that the serving base station 153 of the second UE is also the serving base station of the first UE, and may be collectively referred to as the serving base station 153. After the method shown in fig. 16, as shown in fig. 18, the method may further include:

1515, the serving base station 153 generates the first configuration information.

Specifically, the serving base station 153 may generate the first configuration information for the D2D link according to the second feedback information and according to the communication status of the whole network.

1516, the serving base station 153 generates the second configuration information.

1517, the serving base station 153 transmits the first configuration information to the first UE 151.

1518, the serving base station 153 sends the second configuration information to the first UE 152.

1516 and 1518 may not be performed. In this way, signaling overhead can be reduced.

1519, the first UE 151 adjusts the configuration parameters according to the first configuration information.

1520, the first UE 151 sends the subsequent data packets to the second UE152 according to the adjusted configuration parameters.

Alternatively, the first UE 151 may send the transmission resource to the second UE152 (not shown in fig. 18) through the SA indication information, so that the second UE152 receives the subsequent data packet according to the transmission resource.

It should be noted that the sequence numbers here do not constitute a limitation on the execution order. For example, 1515 may be performed concurrently with 1516. For example, 1518 may be performed before 1517. The invention is not limited in this regard.

Fig. 19 is a block diagram of a user equipment according to another embodiment of the present invention. The user equipment 1900 shown in fig. 19 is a second UE and includes a processor 1901, a receiver 1902, a transmitter 1903 and a memory 1904.

The receiver 1902 is configured to receive a transmission signal transmitted by a first UE, wherein the transmission signal is transmitted over a D2D link between the first UE and the second UE;

the processor 1901 is configured to generate first feedback information according to the transmission signal received by the receiver 1902;

the transmitter 1903 is configured to transmit the first feedback information generated by the processor 1901 to the first UE.

The various components in user device 1900 are coupled together by a bus system 1905, where bus system 1905 includes a power bus, a control bus, and a status signal bus in addition to a data bus. But for clarity of illustration the various buses are labeled as bus system 1905 in figure 19.

The method disclosed in the above embodiments of the present invention may be applied to the processor 1901, or implemented by the processor 1901. The processor 1901 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the method may be performed by integrated logic circuits of hardware or instructions in the form of software in the processor 1901. The Processor 1901 may be a general-purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, or discrete hardware components. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory 1904, and the processor 1901 reads the information in the memory 1904 and completes the steps of the method in combination with the hardware thereof.

It is to be appreciated that the memory 1904 in embodiments of the present invention can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile Memory may be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash Memory. Volatile Memory can be Random Access Memory (RAM), which acts as external cache Memory. By way of example, but not limitation, many forms of RAM are available, such as Static random access memory (Static RAM, SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic random access memory (Synchronous DRAM, SDRAM), Double Data Rate Synchronous Dynamic random access memory (DDR SDRAM), Enhanced Synchronous SDRAM (ESDRAM), Synchronous link SDRAM (SLDRAM), and Direct Rambus RAM (DR RAM). The memory 1904 of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It is to be understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For a hardware implementation, the processor 1901 may be implemented within one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), general purpose processors, controllers, micro-controllers, microprocessors, other electronic units configured to perform the functions described herein, or a combination thereof.

When the embodiments are implemented in software, firmware, middleware or microcode, program code or code segments, they may be stored in a machine-readable medium, such as a storage component. A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be incorporated into another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted using any suitable means including memory sharing, message passing, token passing, network transmission, etc.

For a software implementation, the techniques described herein may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in memory units and executed by processors. The memory unit may be implemented within the processor or external to the processor, in which case it can be communicatively coupled to the processor via various means as is known in the art.

Optionally, as an embodiment, the transmission signal is a first reference signal, the first reference signal is used for performing quality measurement on the D2D link, and the first feedback information includes signal quality information and/or transmission power information of the D2D link.

Optionally, as another embodiment, the transmitter 1903 is further configured to transmit the first feedback information to a serving base station of the second UE.

Optionally, as another embodiment, the transmission signal is a data packet, and the first feedback information includes: and the second UE demodulates the data packet to obtain response information, wherein the response information is acknowledgement information ACK which is correctly demodulated or negative acknowledgement information NACK which is incorrectly demodulated.

Optionally, as another embodiment, the data packet includes first indication information, where the first indication information is used to indicate at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.

Optionally, as another embodiment, the first feedback information further includes signal quality information and/or transmission power information of the D2D link.

Optionally, as another embodiment, the processor 1901 is further configured to generate second feedback information according to a result of the demodulation, where the second feedback information includes signal quality information and/or transmission power information of the D2D link. The transmitter 1903 is further configured to transmit the second feedback information generated by the processor 1901 to a serving base station of the first UE and/or the second UE.

Optionally, as another embodiment, the transmitter 1903 transmits the second feedback information to the serving base station of the second UE, where the second feedback information further includes first indication information, where the first indication information is used to indicate at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.

Optionally, as another embodiment, before the receiver 1902 receives the transmission signal sent by the first UE, the receiver 1902 is further configured to: receiving Scheduling Assignment (SA) indication information sent by the first UE, wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: modulating coding mode MCS, transmitting power and time-frequency resources; the receiver 1902 is specifically configured to: and receiving the transmitting signal sent by the first UE according to the SA indication information.

Optionally, as another embodiment, the processor 1901 is further configured to generate a second reference signal according to the transmission signal, where the second reference signal is determined according to a predefined sequence; the transmitter 1903 is also configured to transmit the second reference signal to the first UE.

Optionally, as another embodiment, the first feedback information includes a second reference signal, wherein the second reference signal is determined according to a predefined sequence.

Optionally, as another embodiment, the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI; the transmission power information includes a value of transmission power and/or adjustment information of transmission power.

Optionally, as another embodiment, the transmitter 1903 is specifically configured to transmit the first feedback information to the first UE according to a feedback resource.

Optionally, as another embodiment, before the transmitter 1903 transmits the first feedback information to the first UE, the receiver 1902 is further configured to: and receiving configuration information sent by a serving base station of the second UE, wherein the configuration information comprises second indication information, and the second indication information is used for indicating the position of the feedback resource.

Optionally, as another embodiment, before the transmitter 1903 transmits the first feedback information to the first UE, the receiver 1902 is further configured to obtain association information and receive a transmission resource transmitted by the first UE, where the association information is used to indicate an association relationship between the transmission resource and the feedback resource, and the association information is predefined or received from a serving base station of the second UE; the processor 1901 is also configured to determine the feedback resources according to the association information and the transmission resources.

Optionally, as another embodiment, before the transmitter 1903 transmits the first feedback information to the first UE, the receiver 1902 is further configured to: receiving the feedback resource sent by the first UE, wherein the feedback resource is determined by the first UE according to a transmission resource and association information, and the association information is used for indicating an association relationship between the transmission resource and the feedback resource.

Optionally, as another embodiment, the feedback resource is autonomously selected by the second UE from a feedback resource pool, wherein the feedback resource pool is pre-configured or received from a serving base station of the second UE.

Optionally, as another embodiment, the first UE and the second UE are located in the same cell, and a serving base station of the first UE and a serving base station of the second UE are the same base station.

The user equipment 1900 shown in fig. 19 can implement the method implemented by the second UE in the foregoing embodiment, and is not described herein again to avoid repetition.

Fig. 20 is a block diagram of a user equipment according to another embodiment of the present invention. The UE2000 shown in fig. 20 is a first UE, and includes: a processor 2001, a receiver 2002, a transmitter 2003, and a memory 2004.

A processor 2001 for generating a transmission signal;

a transmitter 2003 for transmitting the transmission signal generated by the processor 2001 to a second UE, wherein the transmission signal is transmitted over a D2D link between the first UE and the second UE;

a receiver 2002, configured to receive the first feedback information sent by the second UE.

The various components in user device 2000 are coupled together by a bus system 2005, where bus system 2005 includes a power bus, a control bus, and a status signal bus, in addition to a data bus. For clarity of illustration, however, the various buses are labeled as bus system 2005 in fig. 20.

The methods disclosed in the embodiments of the present invention may be applied to the processor 2001, or may be implemented by the processor 2001. The processor 2001 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware or instructions in the form of software in the processor 2001. The processor 2001 described above may be a general purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory 2004, and the processor 2001 reads the information in the memory 2004 and, in conjunction with its hardware, performs the steps of the method described above.

It will be appreciated that the memory 2004 in embodiments of the invention can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile memory may be a ROM, PROM, EPROM, EEPROM, or flash memory, among others. Volatile memory can be RAM, which acts as external cache memory. By way of example and not limitation, many forms of RAM are available, such as SRAM, DRAM, SDRAM, DDR SDRAM, ESDRAM, SLDRAM, and DR RAM. The memory 2004 of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It is to be understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For a hardware implementation, the processor 2001 may be implemented within one or more ASICs, DSPs, DSPDs, PLDs, FPGAs, general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.

Optionally, as another embodiment, the transmission signal is a data packet, and the first feedback information includes acknowledgement information obtained by demodulating the data packet by the second UE, where the acknowledgement information is acknowledgement information ACK that is demodulated correctly or negative acknowledgement information NACK that is demodulated incorrectly.

Optionally, as another embodiment, the first feedback information further includes: signal quality information and/or transmit power information for the D2D link.

Optionally, as another embodiment, the receiver 2002 is further configured to receive second feedback information sent by the second UE, where the second feedback information includes signal quality information and/or transmission power information of the D2D link.

Optionally, as another embodiment, if the first feedback information includes ACK, the processor 2001 is further configured to: sending a data packet to be sent to the second UE according to the current configuration parameters; or, the retransmission packet which is not transmitted of the sent data packet is stopped, and the new data packet to be sent is sent to the second UE according to the current configuration parameters.

Optionally, as another embodiment, if the first feedback information includes ACK, the processor 2001 is further configured to: adjusting configuration parameters according to the signal quality information and/or the transmitting power information; and sending the data packet to be sent to the second UE according to the adjusted configuration parameters.

Optionally, as another embodiment, if the first feedback information includes NACK, the processor 2001 is further configured to: if the retransmission packet of the sent data packet is not sent completely, sending the retransmission packet of the sent data packet to the second UE according to the current configuration parameters; or, if the retransmission packet of the transmitted data packet has been transmitted, increasing the retransmission times of the transmitted data packet or changing the retransmission pattern, and transmitting the retransmission packet of the transmitted data packet to the second UE.

Optionally, as another embodiment, if the first feedback information includes NACK, the processor 2001 is further configured to: if the retransmission packet of the sent data packet is not sent completely, adjusting configuration parameters according to the signal quality information and/or the transmitting power information; and sending the retransmission packet of the sent data packet to the second UE according to the adjusted configuration parameters.

Optionally, as another embodiment, if the first feedback information includes NACK, the processor 2001 is further configured to: if the retransmission packet of the sent data packet is sent completely, adjusting configuration parameters according to the signal quality information and/or the transmitting power information; and sending the subsequent data packet to the second UE according to the adjusted configuration parameter.

Optionally, as another embodiment, the receiver 2002 is further configured to receive first configuration information sent by a serving base station of the first UE, where the first configuration information includes at least one of the following: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of a used Modulation and Coding Scheme (MCS), and indication information of used time-frequency resources, and the first configuration information is determined by the serving base station of the first UE according to second feedback information sent by the second UE. The processor 2001 is further configured to adjust configuration parameters according to the first configuration information.

The transmitter 2003 is further configured to transmit subsequent data packets to the second UE according to the adjusted configuration parameters.

Optionally, as another embodiment, the first configuration information further includes information indicating an ID of the D2D link.

Optionally, as another embodiment, the configuration parameter includes at least one of the following: modulation Coding Scheme (MCS) level, retransmission times, retransmission pattern information, transmitting power information and indication information of time frequency resources.

Optionally, as another embodiment, before the transmitter 2003 transmits the transmission signal to the second UE, the transmitter 2003 is further configured to: sending Scheduling Assignment (SA) indication information to the second UE so that the second UE receives the transmission signal according to the SA indication information, wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: modulation coding scheme MCS, transmitting power and time frequency resources.

Optionally, as another embodiment, the receiver 2002 is further configured to receive a second reference signal transmitted by the second UE, where the second reference signal is determined according to a predefined sequence.

Optionally, as another embodiment, the first feedback information further includes a second reference signal, wherein the second reference signal is determined according to a predefined sequence.

Optionally, as another embodiment, the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI. The transmission power information includes a value of transmission power and/or adjustment information of transmission power.

Optionally, as another embodiment, the transmitter 2003 is specifically configured to: and sending the transmission signal to the second UE according to the transmission resource.

Optionally, as another embodiment, before the transmitter 2003 transmits the transmission signal to the second UE, the receiver 2002 is further configured to: receiving second configuration information sent by a serving base station of the first UE, wherein the second configuration information includes second indication information, and the second indication information is used for indicating the position of the transmission resource.

Optionally, as another embodiment, the transmission resource is autonomously selected by the first UE from a pool of transmission resources, wherein the pool of transmission resources is pre-configured or received from a serving base station of the first UE.

Optionally, as another embodiment, before the transmitter 2003 transmits the transmission signal to the second UE, the receiver 2002 is further configured to obtain association information and receive a feedback resource transmitted by the second UE, where the association information is used to indicate an association relationship between the transmission resource and the feedback resource, and the association information is predefined or received from a serving base station of the first UE. The processor 2001 is further configured to determine the transmission resource based on the association information and the feedback resource.

Optionally, as another embodiment, before the receiver 2002 receives the first feedback information sent by the second UE, the receiver 2002 is further configured to obtain association information, where the association information is used to indicate an association relationship between the transmission resource and a feedback resource, and the association information is predefined or received from a serving base station of the first UE. The processor 2001 is further configured to determine a feedback resource based on the association information and the transmission resource.

Optionally, as another embodiment, the receiver 2002 is specifically configured to receive the first feedback information sent by the second UE according to the feedback resource.

The UE2000 shown in fig. 20 can implement the method implemented by the first UE in the foregoing embodiment, and is not described herein again to avoid repetition.

Fig. 21 is a block diagram of a base station according to another embodiment of the present invention. The base station 2100 shown in fig. 21 includes a processor 2101, a receiver 2102, a transmitter 2103, and a memory 2104.

The receiver 2102 is configured to receive feedback information sent by a second UE, wherein the feedback information includes signal quality information and/or transmission power information of a D2D link between a first UE and the second UE;

the processor 2101 is configured to generate first configuration information according to the feedback information received by the receiver 2102;

the transmitter 2103 is configured to transmit the first configuration information generated by the processor 2101 to a first UE, where the base station is a serving base station of the first UE.

The various components in the base station 2100 are coupled together by a bus system 2105, wherein the bus system 2105 includes a power bus, a control bus, and a status signal bus in addition to a data bus. For clarity of illustration, however, the various buses are labeled in fig. 21 as bus system 2105.

The method disclosed by the embodiment of the invention can be applied to the processor 2101 or realized by the processor 2101. The processor 2101 may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above method may be implemented by hardware integrated logic circuits in the processor 2101 or instructions in the form of software. The processor 2101 described above may be a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory 2104, and the processor 2101 reads the information in the memory 2104 and, in combination with its hardware, performs the steps of the above-described method.

It is to be appreciated that the memory 2104 in embodiments of the present invention can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile memory may be a ROM, PROM, EPROM, EEPROM, or flash memory, among others. Volatile memory can be RAM, which acts as external cache memory. By way of example and not limitation, many forms of RAM are available, such as SRAM, DRAM, SDRAM, DDR SDRAM, ESDRAM, SLDRAM, and DR RAM. The memory 2104 of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It is to be understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For a hardware implementation, the processor 2101 may be implemented within one or more ASICs, DSPs, DSPDs, PLDs, FPGAs, general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.

Optionally, as an embodiment, the transmitter 2103 is further configured to transmit second configuration information to the first UE, where the second configuration information includes a transmission resource pool and/or association information for the D2D link, and the association information is used to indicate an association relationship between a transmission resource and a feedback resource.

Optionally, as another embodiment, the first UE and the second UE are located in the same cell, and the transmitter 2103 is further configured to transmit third configuration information to the second UE, where the third configuration information includes a feedback resource pool and/or association information for the D2D link, and the association information is used to indicate an association relationship between transmission resources and feedback resources.

Optionally, as another embodiment, the first UE and the second UE are located in different cells, and the receiver 2102 is specifically configured to: and receiving feedback information sent by the second UE from a serving base station of the second UE.

Optionally, as another embodiment, the first configuration information includes at least one of: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of Modulation and Coding Scheme (MCS) used and indication information of time-frequency resources used.

Optionally, as another embodiment, the first configuration information further includes information indicating an identification ID of the D2D link.

Optionally, as another embodiment, the feedback information further includes indication information, where the indication information is used to indicate at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.

The base station 2100 shown in fig. 21 can implement the method implemented by the serving base station of the first UE in the foregoing embodiment, and is not repeated here to avoid redundancy.

Fig. 22 is a block diagram of a base station according to another embodiment of the present invention. The base station 2200 shown in fig. 22 is a second base station including: a processor 2201, a receiver 2202, a transmitter 2203, and a memory 2204.

The receiver 2202 is configured to receive feedback information sent by a second UE, where the feedback information includes signal quality information and/or transmission power information of a D2D link between a first UE and the second UE, and the second base station is a serving base station of the second UE;

the transmitter 2203 is configured to send the feedback information received by the receiver 2202 to a first base station, where the first base station is a serving base station of a first UE, and the first UE and the second UE are located in different cells.

The various components in the base station 2200 are coupled together by a bus system 2205, wherein the bus system 2205 includes a power bus, a control bus, and a status signal bus in addition to a data bus. For clarity of illustration, however, the various buses are labeled in fig. 22 as the bus system 2205.

The method disclosed by the above embodiment of the present invention can be applied to the processor 2201, or implemented by the processor 2201. The processor 2201 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware or instructions in the form of software in the processor 2201. The processor 2201 may be a general purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory 2204, and the processor 2201 reads the information in the memory 2204 and completes the steps of the method in combination with the hardware.

It is to be understood that the memory 2204 in embodiments of the present invention can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile memory may be a ROM, PROM, EPROM, EEPROM, or flash memory, among others. Volatile memory can be RAM, which acts as external cache memory. By way of example and not limitation, many forms of RAM are available, such as SRAM, DRAM, SDRAM, DDR SDRAM, ESDRAM, SLDRAM, and DR RAM. The memory 2204 of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It is to be understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For a hardware implementation, the processor 2201 may be implemented within one or more ASICs, DSPs, DSPDs, PLDs, FPGAs, general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.

Optionally, as an embodiment, the transmitter 2203 is further configured to transmit configuration information to the second UE. Wherein the configuration information comprises a feedback resource pool and/or association information for the D2D link, and the association information is used for indicating an association relationship between transmission resources and feedback resources.

Optionally, as another embodiment, the feedback information further includes indication information, where the indication information is used to indicate at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.

When the first UE and the second UE are located in different cells, the base station 2200 shown in fig. 22 can implement the method implemented by the serving base station of the second UE in the foregoing embodiment, and is not repeated here to avoid repeated description.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

A User Equipment (UE), wherein the UE is a second UE, comprising:

a receiving unit, configured to receive a transmission signal sent by a first UE, where the transmission signal is transmitted through a D2D link between the first UE and the second UE;

the processing unit is used for generating first feedback information according to the transmitting signal received by the receiving unit;

a sending unit, configured to send the first feedback information generated by the processing unit to the first UE.
The UE of claim 1, wherein the transmitted signal is a first reference signal used for quality measurements of the D2D link,

the first feedback information includes signal quality information and/or transmit power information of the D2D link.
The UE of claim 2, wherein the sending unit is further configured to send the first feedback information to a serving base station of the second UE.
The UE of claim 1, wherein the transmission signal is a data packet,

the first feedback information includes: and the second UE demodulates the data packet to obtain response information, wherein the response information is acknowledgement information ACK which is correctly demodulated or negative acknowledgement information NACK which is incorrectly demodulated.
The UE of claim 4, wherein the data packet comprises first indication information, and wherein the first indication information is used for indicating at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.
The UE of claim 4 or 5, wherein the first feedback information further comprises signal quality information and/or transmit power information of the D2D link.
The UE of claim 4 or 5,

the processing unit is further configured to generate second feedback information according to the result of the demodulation, where the second feedback information includes signal quality information and/or transmission power information of the D2D link;

the sending unit is further configured to send the second feedback information generated by the processing unit to a serving base station of the first UE and/or the second UE.
The UE of claim 7, wherein the sending unit sends the second feedback information to a serving base station of the second UE,

the second feedback information further includes first indication information, wherein the first indication information is used for indicating at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.
The UE of any of claims 4 to 8, wherein, prior to the receiving unit receiving the transmission signal sent by the first UE,

the receiving unit is further configured to: receiving Scheduling Assignment (SA) indication information sent by the first UE, wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: modulating coding mode MCS, transmitting power and time-frequency resources;

the receiving unit is specifically configured to: and receiving the transmitting signal sent by the first UE according to the SA indication information.
The UE of any of claims 4 to 9,

the processing unit is further configured to generate a second reference signal according to the transmission signal, wherein the second reference signal is determined according to a predefined sequence;

the sending unit is further configured to send the second reference signal to the first UE.
The UE of any of claims 4 to 9, wherein the first feedback information comprises a second reference signal, wherein the second reference signal is determined according to a predefined sequence.
The UE of claim 2 or 6 or 7,

the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

the transmission power information includes a value of transmission power and/or adjustment information of transmission power.
The UE of any one of claims 1 to 12, wherein the sending unit is specifically configured to send the first feedback information to the first UE according to a feedback resource.
The UE of claim 13, wherein before the sending unit sends the first feedback information to the first UE,

the receiving unit is further configured to: and receiving configuration information sent by a serving base station of the second UE, wherein the configuration information comprises second indication information, and the second indication information is used for indicating the position of the feedback resource.
The UE of claim 13, wherein before the sending unit sends the first feedback information to the first UE,

the receiving unit is further configured to acquire association information and receive a transmission resource sent by the first UE, where the association information is used to indicate an association relationship between the transmission resource and the feedback resource, and the association information is predefined or received from a serving base station of the second UE;

the processing unit is further configured to determine the feedback resource according to the association information and the transmission resource.
The UE of claim 13, wherein before the sending unit sends the first feedback information to the first UE, the receiving unit is further configured to:

receiving the feedback resource sent by the first UE, wherein the feedback resource is determined by the first UE according to a transmission resource and association information, and the association information is used for indicating an association relationship between the transmission resource and the feedback resource.
The UE of claim 13, wherein the feedback resource is autonomously selected by the second UE from a feedback resource pool, wherein the feedback resource pool is pre-configured or received from a serving base station of the second UE.
The UE of any one of claims 1 to 17, wherein the first UE and the second UE are located in a same cell, and wherein a serving base station of the first UE and a serving base station of the second UE are the same base station.
A User Equipment (UE), wherein the UE is a first UE, comprising:

a processing unit for generating a transmission signal;

a sending unit, configured to send the transmission signal generated by the processing unit to a second UE, where the transmission signal is transmitted through a D2D link between the first UE and the second UE;

a receiving unit, configured to receive the first feedback information sent by the second UE.
The UE of claim 19, wherein the transmitted signal is a first reference signal used for quality measurements of the D2D link,

the first feedback information includes signal quality information and/or transmit power information of the D2D link.
The UE of claim 19, wherein the transmission signal is a data packet, and wherein the first feedback information comprises acknowledgement information of the second UE after demodulating the data packet, wherein the acknowledgement information is ACK for correct demodulation or NACK for wrong demodulation.
The UE of claim 21, wherein the data packet comprises first indication information, and wherein the first indication information indicates at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.
The UE of claim 21 or 22, wherein the first feedback information further comprises: signal quality information and/or transmit power information for the D2D link.
The UE of claim 21 or 22, wherein the receiving unit is further configured to receive second feedback information sent by the second UE, and wherein the second feedback information includes signal quality information and/or transmission power information of the D2D link.
The UE of any one of claims 21 to 24, wherein if the first feedback information comprises an ACK, the processing unit is further configured to:

sending a data packet to be sent to the second UE according to the current configuration parameters; alternatively, the first and second electrodes may be,

and stopping the retransmission packet which is not transmitted of the transmitted data packet, and transmitting the new data packet to be transmitted to the second UE according to the current configuration parameters.
The UE of claim 23 or 24, wherein if the first feedback information comprises an ACK, the processing unit is further configured to:

adjusting configuration parameters according to the signal quality information and/or the transmitting power information;

and sending the data packet to be sent to the second UE according to the adjusted configuration parameters.
The UE of any one of claims 21 to 24, wherein if the first feedback information comprises a NACK, the processing unit is further configured to:

if the retransmission packet of the sent data packet is not sent completely, sending the retransmission packet of the sent data packet to the second UE according to the current configuration parameters; alternatively, the first and second electrodes may be,

and if the retransmission packet of the sent data packet is sent completely, increasing the retransmission times of the sent data packet or changing a retransmission pattern, and sending the retransmission packet of the sent data packet to the second UE.
The UE of claim 23 or 24, wherein if the first feedback information comprises a NACK, the processing unit is further configured to:

if the retransmission packet of the sent data packet is not sent completely, adjusting configuration parameters according to the signal quality information and/or the transmitting power information;

and sending the retransmission packet of the sent data packet to the second UE according to the adjusted configuration parameters.
The UE of claim 23 or 24, wherein if the first feedback information comprises a NACK, the processing unit is further configured to:

if the retransmission packet of the sent data packet is sent completely, adjusting configuration parameters according to the signal quality information and/or the transmitting power information;

and sending the subsequent data packet to the second UE according to the adjusted configuration parameter.
The UE of any of claims 21 to 29,

the receiving unit is further configured to receive first configuration information sent by a serving base station of the first UE, where the first configuration information includes at least one of: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of a used Modulation and Coding Scheme (MCS) and indication information of used time-frequency resources, wherein the first configuration information is determined by a serving base station of the first UE according to second feedback information sent by the second UE;

the processing unit is further configured to adjust configuration parameters according to the first configuration information;

the sending unit is further configured to send a subsequent data packet to the second UE according to the adjusted configuration parameter.
The UE of claim 30, wherein the first configuration information further comprises information indicating an ID of the D2D link.
The UE of any of claims 25 to 31, wherein the configuration parameters comprise at least one of: modulation Coding Scheme (MCS) level, retransmission times, retransmission pattern information, transmitting power information and indication information of time frequency resources.
The UE of any of claims 21 to 32, wherein before the sending unit sends the transmission signal to the second UE, the sending unit is further configured to:

transmitting scheduling assignment SA indication information to the second UE so that the second UE receives the transmission signal according to the SA indication information,

wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: modulation coding scheme MCS, transmitting power and time frequency resources.
The UE of any of claims 21 to 32,

the receiving unit is further configured to receive a second reference signal transmitted by the second UE, where the second reference signal is determined according to a predefined sequence.
The UE of any of claims 21 to 32, wherein the first feedback information further comprises a second reference signal, wherein the second reference signal is determined according to a predefined sequence.
The UE of claim 20 or 23 or 24,

the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

the transmission power information includes a value of transmission power and/or adjustment information of transmission power.
The UE of any one of claims 19 to 36, wherein the sending unit is specifically configured to: and sending the transmission signal to the second UE according to the transmission resource.
The UE of claim 37, wherein before the sending unit sends the transmission signal to a second UE, the receiving unit is further configured to:

receiving second configuration information sent by a serving base station of the first UE, wherein the second configuration information includes second indication information, and the second indication information is used for indicating the position of the transmission resource.
The UE of claim 37, wherein the transmission resource is autonomously selected by the first UE from a pool of transmission resources, wherein the pool of transmission resources is pre-configured or the pool of transmission resources is received from a serving base station of the first UE.
The UE of claim 37, wherein before the sending unit sends the transmission signal to a second UE,

the receiving unit is further configured to acquire association information and receive a feedback resource sent by the second UE, where the association information is used to indicate an association relationship between the transmission resource and the feedback resource, and the association information is predefined or received from a serving base station of the first UE;

the processing unit is further configured to determine the transmission resource according to the association information and the feedback resource.
The UE of any of claims 37 to 40, wherein before the receiving unit receives the first feedback information sent by the second UE,

the receiving unit is further configured to obtain association information, where the association information is used to indicate an association relationship between the transmission resource and a feedback resource, and the association information is predefined or received from a serving base station of the first UE;

the processing unit is further configured to determine a feedback resource according to the association information and the transmission resource.
The UE of claim 41, wherein the receiving unit is specifically configured to: and receiving the first feedback information sent by the second UE according to the feedback resource.
The UE of claims 19 to 42, wherein the first UE and the second UE are located in a same cell, and wherein the serving base station of the first UE and the serving base station of the second UE are the same base station.
A base station, comprising:

a receiving unit, configured to receive feedback information sent by a second user equipment UE, where the feedback information includes signal quality information and/or transmission power information of a D2D link between a first UE and the second UE;

the processing unit is used for generating first configuration information according to the feedback information received by the receiving unit;

a sending unit, configured to send the first configuration information generated by the processing unit to a first UE, where the base station is a serving base station of the first UE.
The base station of claim 44, wherein the sending unit is further configured to send second configuration information to the first UE,

wherein the second configuration information comprises a transmission resource pool and/or association information for the D2D link, the association information being used for indicating an association relationship between transmission resources and feedback resources.
The base station according to claim 44 or 45, wherein the first UE and the second UE are located in the same cell, and wherein the sending unit is further configured to send third configuration information to the second UE,

wherein the third configuration information comprises a feedback resource pool and/or association information for the D2D link, the association information being used for indicating an association between transmission resources and feedback resources.
The base station according to claim 44 or 45, wherein the first UE and the second UE are located in different cells, and the receiving unit is specifically configured to:

and receiving feedback information sent by the second UE from a serving base station of the second UE.
The base station according to any of claims 44 to 47, wherein the first configuration information comprises at least one of: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of Modulation and Coding Scheme (MCS) used and indication information of time-frequency resources used.
The base station of claim 48, wherein the first configuration information further comprises information indicating an Identification (ID) of the D2D link.
The base station according to any of claims 44 to 49, wherein the feedback information further comprises indication information, wherein the indication information is used to indicate at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.
The base station according to any of claims 44 to 50,

the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

the transmission power information includes a value of transmission power and/or adjustment information of transmission power.
A base station, wherein the base station is a second base station, comprising:

a receiving unit, configured to receive feedback information sent by a second user equipment UE, where the feedback information includes signal quality information and/or transmission power information of a D2D link between a first UE and the second UE, and the second base station is a serving base station of the second UE;

and the sending unit is used for sending the feedback information received by the receiving unit to a first base station, the first base station is a service base station of first UE, and the first UE and the second UE are located in different cells.
The base station of claim 52, wherein the sending unit is further configured to send configuration information to the second UE,

wherein the configuration information comprises a feedback resource pool and/or association information for the D2D link, and the association information is used for indicating an association relationship between transmission resources and feedback resources.
The base station of claim 52 or 53, wherein the feedback information further comprises indication information, wherein the indication information is used for indicating at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.
The base station according to any of claims 52 to 54,

the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

the transmission power information includes a value of transmission power and/or adjustment information of transmission power.
A method of device-to-device D2D communication, comprising:

receiving a transmission signal sent by a first UE by a second UE, wherein the transmission signal is transmitted through a D2D link between the first UE and the second UE;

the second UE generates first feedback information according to the transmitting signal;

and the second UE sends the first feedback information to the first UE.
The method of claim 56, wherein the transmitted signal is a first reference signal used for quality measurement of the D2D link,

the first feedback information includes signal quality information and/or transmit power information of the D2D link.
The method of claim 57, further comprising:

and the second UE sends the first feedback information to a service base station of the second UE.
The method of claim 56, wherein the transmitted signal is a data packet,

the first feedback information includes: and the second UE demodulates the data packet to obtain response information, wherein the response information is acknowledgement information ACK which is correctly demodulated or negative acknowledgement information NACK which is incorrectly demodulated.
The method of claim 59, wherein the data packet comprises a first indication information, and wherein the first indication information is used for indicating at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.
The method according to claim 59 or 60, wherein the first feedback information further comprises signal quality information and/or transmit power information of the D2D link.
The method of claim 59 or 60, further comprising:

the second UE generates second feedback information according to the demodulation result, wherein the second feedback information comprises signal quality information and/or transmission power information of the D2D link;

and the second UE sends the second feedback information to the first UE and/or a service base station of the second UE.
The method of claim 62, wherein the second UE sends the second feedback information to a serving base station of the second UE,

the second feedback information further includes first indication information, wherein the first indication information is used for indicating at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.
The method according to any of claims 59 to 63, further comprising, before the second UE receives the transmission signal sent by the first UE:

the second UE receives scheduling assignment SA indication information sent by the first UE, wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: modulating coding mode MCS, transmitting power and time-frequency resources;

the second UE receiving the transmission signal sent by the first UE, including:

and the second UE receives the transmitting signal sent by the first UE according to the SA indication information.
The method of any one of claims 59 to 64, further comprising:

the second UE generates a second reference signal according to the transmission signal, wherein the second reference signal is determined according to a predefined sequence;

the second UE sends the second reference signal to the first UE.
The method according to any one of claims 59 to 64, wherein the first feedback information comprises a second reference signal, wherein the second reference signal is determined according to a predefined sequence.
The method of claim 57, 61 or 62,

the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

the transmission power information includes a value of transmission power and/or adjustment information of transmission power.
The method according to any of claims 56 to 67, wherein the second UE sending the first feedback information to the first UE comprises:

and the second UE sends the first feedback information to the first UE according to the feedback resource.
The method of claim 68, wherein before the second UE sends the first feedback information to the first UE, further comprising:

and the second UE receives configuration information sent by a serving base station of the second UE, wherein the configuration information comprises second indication information, and the second indication information is used for indicating the position of the feedback resource.
The method of claim 68, wherein before the second UE sends the first feedback information to the first UE, further comprising:

the second UE acquires association information and receives the transmission resource sent by the first UE, wherein the association information is used for indicating the association relationship between the transmission resource and the feedback resource, and the association information is predefined or received from a serving base station of the second UE;

and the second UE determines the feedback resource according to the association information and the transmitting resource.
The method of claim 68, wherein before the second UE sends the first feedback information to the first UE, further comprising:

and the second UE receives the feedback resource sent by the first UE, wherein the feedback resource is determined by the first UE according to a transmission resource and association information, and the association information is used for indicating an association relation between the transmission resource and the feedback resource.
The method of claim 68, wherein the feedback resource is autonomously selected by the second UE from a feedback resource pool, wherein the feedback resource pool is pre-configured or received from a serving base station of the second UE.
The method of any of claims 56 to 72, wherein the first UE and the second UE are located in the same cell, and wherein the serving base station of the first UE and the serving base station of the second UE are the same base station.
A method of device-to-device D2D communication, comprising:

a first User Equipment (UE) generates a transmission signal;

the first UE sends the transmission signal to a second UE, wherein the transmission signal is transmitted through a D2D link between the first UE and the second UE;

and the first UE receives first feedback information sent by the second UE.
The method of claim 74, wherein the transmitted signal is a first reference signal used for quality measurement of the D2D link,

the first feedback information includes signal quality information and/or transmit power information of the D2D link.
The method of claim 74, wherein the transmitted signal is a data packet, and wherein the first feedback information comprises acknowledgement information demodulated from the data packet by the second UE, wherein the acknowledgement information is a correctly demodulated acknowledgement information (ACK) or a incorrectly demodulated negative acknowledgement information (NACK).
The method of claim 76, wherein the data packet comprises first indication information, and wherein the first indication information is used to indicate at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.
The method of claim 76 or 77, wherein the first feedback information further comprises: signal quality information and/or transmit power information for the D2D link.
The method of claim 76 or 77, further comprising:

and the first UE receives second feedback information sent by the second UE, wherein the second feedback information comprises signal quality information and/or transmission power information of the D2D link.
The method according to any one of claims 76 to 79, wherein if the first feedback information comprises ACK, further comprising:

the first UE sends a data packet to be sent to the second UE according to the current configuration parameters; alternatively, the first and second electrodes may be,

and the first UE stops the retransmission packet which is not transmitted of the transmitted data packet and transmits a new data packet to be transmitted to the second UE according to the current configuration parameters.
The method of claim 78 or 79, wherein if the first feedback information comprises an ACK, further comprising:

the first UE adjusts configuration parameters according to the signal quality information and/or the transmitting power information;

and the first UE sends the data packet to be sent to the second UE according to the adjusted configuration parameters.
The method according to any of claims 76 to 79, wherein if said first feedback information comprises a NACK, further comprising:

if the retransmission packet of the sent data packet is not sent completely, the first UE sends the retransmission packet of the sent data packet to the second UE according to the current configuration parameters; alternatively, the first and second electrodes may be,

if the retransmission packet of the transmitted data packet is already transmitted, the first UE increases the retransmission times of the transmitted data packet or changes the retransmission pattern, and transmits the retransmission packet of the transmitted data packet to the second UE.
The method according to claim 78 or 79, wherein if the first feedback information comprises a NACK, further comprising:

if the retransmission packet of the sent data packet is not sent completely, the first UE adjusts configuration parameters according to the signal quality information and/or the transmission power information;

and the first UE sends the retransmission packet of the sent data packet to the second UE according to the adjusted configuration parameters.
The method according to claim 78 or 79, wherein if the first feedback information comprises a NACK, further comprising:

if the retransmission packet of the sent data packet is sent completely, the first UE adjusts configuration parameters according to the signal quality information and/or the transmission power information;

and the first UE sends the subsequent data packet to the second UE according to the adjusted configuration parameters.
The method of any one of claims 76 to 84, further comprising:

the first UE receives first configuration information sent by a serving base station of the first UE, wherein the first configuration information comprises at least one of the following: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of a used Modulation and Coding Scheme (MCS) and indication information of used time-frequency resources, wherein the first configuration information is determined by a serving base station of the first UE according to second feedback information sent by the second UE;

and the first UE adjusts configuration parameters according to the first configuration information and sends subsequent data packets to the second UE according to the adjusted configuration parameters.
The method of claim 85, wherein the first configuration information further comprises information indicating an ID of the D2D link.
The method of any one of claims 80 to 86, wherein the configuration parameters comprise at least one of: modulation Coding Scheme (MCS) level, retransmission times, retransmission pattern information, transmitting power information and indication information of time frequency resources.
The method of any one of claims 76 to 87, wherein before the first UE sends the transmission signal to a second UE, further comprising:

the first UE sends scheduling assignment SA indication information to the second UE so that the second UE receives the transmission signal according to the SA indication information,

wherein the SA indication information comprises information of transmission resources to be used by the first UE, and the transmission resources comprise at least one of the following: modulation coding scheme MCS, transmitting power and time frequency resources.
The method of any one of claims 76 to 87, further comprising:

the first UE receives a second reference signal transmitted by the second UE, wherein the second reference signal is determined according to a predefined sequence.
The method of any one of claims 76 to 87, wherein the first feedback information further comprises a second reference signal, wherein the second reference signal is determined according to a predefined sequence.
The method of claim 75 or 78 or 79,

the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

the transmission power information includes a value of transmission power and/or adjustment information of transmission power.
The method of any of claims 74-91, wherein the first UE sending the transmission signal to a second UE comprises:

and the first UE sends the transmission signal to the second UE according to the transmission resource.
The method of claim 92, further comprising, prior to the first UE transmitting the transmission signal to a second UE:

the first UE receives second configuration information sent by a serving base station of the first UE, wherein the second configuration information comprises second indication information, and the second indication information is used for indicating the position of the transmission resource.
The method of claim 92, wherein the transmission resource is autonomously selected by the first UE from a pool of transmission resources, wherein the pool of transmission resources is pre-configured or wherein the pool of transmission resources is received from a serving base station of the first UE.
The method of claim 92, further comprising, prior to the first UE transmitting the transmission signal to a second UE:

the first UE acquires association information and receives a feedback resource sent by the second UE, wherein the association information is used for indicating an association relation between the transmission resource and the feedback resource, and the association information is predefined or received from a serving base station of the first UE;

and the first UE determines the transmitting resource according to the associated information and the feedback resource.
The method according to any of claims 92 to 95, wherein before the first UE receives the first feedback information sent by the second UE, further comprising:

the first UE acquires association information, wherein the association information is used for indicating an association relation between the transmission resource and a feedback resource, and the association information is predefined or received from a serving base station of the first UE;

and the first UE determines a feedback resource according to the association information and the transmitting resource.
The method of claim 96, wherein the receiving, by the first UE, the first feedback information sent by the second UE comprises:

and the first UE receives the first feedback information sent by the second UE according to the feedback resource.
The method of claims 74-97, wherein the first UE and the second UE are located in a same cell, and wherein a serving base station of the first UE and a serving base station of the second UE are the same base station.
A method for device-to-device D2D communication, comprising:

a base station receives feedback information sent by a second User Equipment (UE), wherein the feedback information comprises signal quality information and/or transmission power information of a D2D link between a first UE and the second UE;

the base station generates first configuration information according to the feedback information;

and the base station sends the first configuration information to first UE, wherein the base station is a service base station of the first UE.
The method of claim 99, further comprising:

the base station transmitting second configuration information to the first UE,

wherein the second configuration information comprises a transmission resource pool and/or association information for the D2D link, the association information being used for indicating an association relationship between transmission resources and feedback resources.
The method of claim 99 or 100, wherein the first UE and the second UE are located in a same cell, further comprising:

the base station transmitting third configuration information to the second UE,

wherein the third configuration information comprises a feedback resource pool and/or association information for the D2D link, the association information being used for indicating an association between transmission resources and feedback resources.
The method of claim 99 or 100, wherein the first UE and the second UE are located in different cells, and wherein the receiving, by the base station, the feedback information sent by the second UE comprises:

and the base station receives the feedback information sent by the second UE from the serving base station of the second UE.
The method of any one of claims 99 to 102, wherein the first configuration information comprises at least one of: configuration information of retransmission times or retransmission patterns, adjustment information of transmission power or transmission power, information of Modulation and Coding Scheme (MCS) used and indication information of time-frequency resources used.
The method of claim 103, wherein the first configuration information further comprises information indicating an Identification (ID) of the D2D link.
The method of any one of claims 99 to 104, wherein the feedback information further comprises indication information, wherein the indication information is used for indicating at least one of the following: the ID of the first UE, the ID of the second UE, and the ID of the D2D link.
The method of any one of claims 99 to 105,

the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

the transmission power information includes a value of transmission power and/or adjustment information of transmission power.
A method for device-to-device D2D communication, comprising:

a second base station receives feedback information sent by a second User Equipment (UE), wherein the feedback information comprises signal quality information and/or transmission power information of a D2D link between a first UE and the second UE, and the second base station is a serving base station of the second UE;

and the second base station sends the feedback information to a first base station, the first base station is a service base station of first UE, and the first UE and the second UE are located in different cells.
The method of claim 107, further comprising:

the second base station sends configuration information to the second UE,

wherein the configuration information comprises a feedback resource pool and/or association information for the D2D link, and the association information is used for indicating an association relationship between transmission resources and feedback resources.
The method of claim 107 or 108, wherein the feedback information further comprises indication information, wherein the indication information is used for indicating at least one of the following: an identification ID of the first UE, an ID of the second UE, and an ID of the D2D link.
The method of any one of claims 107 to 109,

the signal quality information includes at least one of: reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indication (RSSI), Channel Quality Indication (CQI) and adjustment information of the CQI;

the transmission power information includes a value of transmission power and/or adjustment information of transmission power.