Feedback method and device for device-to-device communicationTechnical Field
The present invention relates to wireless mobile communications technologies, and in particular, to a method and an apparatus for feedback of device-to-device communication.
Background
With the development of wireless mobile communication technology, people put higher and higher demands on high speed, low delay and low cost. An Advanced Mobile Telecommunications (IMT-a) system allows Device-to-Device (D2D) communication to be supported under a cellular network to improve spectrum utilization, which will be referred to as D2D communication for convenience of description. Device-to-Device (D2D) communication is a new technology that allows direct communication between terminals through multiplexing of cell resources under control of the system.
At present, in D2D communication, after a sender sends data to a receiver, the sender defaults that the data is successfully sent to the receiver. However, if the receiving end fails to receive the data, the receiving end cannot notify the transmitting end, resulting in low reliability of data transmission and low Quality of Service (QoS).
Disclosure of Invention
The invention provides a feedback method and a feedback device for device-to-device communication, which are used for realizing the reliability and the service quality of data transmission between a D2D sending end and a D2D receiving end.
In a first aspect, an embodiment of the present invention provides a feedback method for device-to-device communication, including:
when target data sent by a sending end of device-to-device communication is received, determining feedback information according to the receiving condition of the target data;
and sending the feedback information to a sending end of the device-to-device communication.
In a second aspect, an embodiment of the present invention further provides a feedback apparatus for device-to-device communication, including:
the device comprises a feedback information determining unit and a feedback information determining unit, wherein the feedback information determining unit is used for determining feedback information according to the receiving condition of target data when the target data sent by a sending end of device-to-device communication is received;
a sending unit, configured to send the feedback information determined by the feedback information determining unit to a sending end of the device-to-device communication.
In the embodiment of the present invention, when receiving target data sent by a sending end, a receiving end of D2D communication can determine feedback information according to a receiving condition of the target data, and feed back the feedback information to the sending end, thereby implementing feedback of the receiving condition of the target data. In the prior art, a receiving end cannot feed back the receiving condition of the target data of the D2D communication to a sending end, so that the data transmission reliability and the quality of a server are low. According to the embodiment of the invention, the receiving end of D2D communication can feed back the feedback information of the target data sent by the sending end to the sending end, so that the sending end can adjust the data sending content according to the feedback information, and the reliability and the service quality of data transmission in D2D communication are improved.
Drawings
Fig. 1 is a flowchart of a feedback method for D2D communication according to an embodiment of the present invention;
fig. 2 is a flowchart of a feedback method for a first D2D communication according to a second embodiment of the present invention;
fig. 3 is a flowchart of a feedback method of a second D2D communication according to a second embodiment of the present invention;
fig. 4 is a flowchart of a feedback method of a third D2D communication according to the second embodiment of the present invention;
fig. 5 is a flowchart of a feedback method of a fourth D2D communication according to the second embodiment of the present invention;
fig. 6 is a flowchart of a feedback method for a first D2D communication according to a third embodiment of the present invention;
fig. 7 is a flowchart of a feedback method of a second D2D communication according to a third embodiment of the present invention;
fig. 8 is a schematic structural diagram of a feedback apparatus for D2D communication according to a fourth embodiment of the present invention;
fig. 9 is a schematic structural diagram of a feedback device for second D2D communication according to a fourth embodiment of the present invention;
fig. 10 is a schematic structural diagram of a feedback device for D2D communication according to a fourth embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
Example one
Fig. 1 is a flowchart of a feedback method for device-to-device D2D communication according to an embodiment of the present invention, where this embodiment is applicable to a case where a sending end sends target data to a receiving end in device-to-device D2D communication, and the method may be executed by the receiving end in D2D communication, and specifically includes the following steps:
step S110, when target data sent by a sending end of the device-to-device communication is received, determining feedback information according to a receiving condition of the target data.
The D2D initiator and the D2D initiator may communicate over a PC5 interface. If the target data is successfully received, the feedback message is an Acknowledgement Character (ACK). If the target data fails to be received, the feedback information is a Negative Acknowledgement (NACK).
Step S120, sending the feedback information to a sending end of the device-to-device communication.
The feedback information is transmitted to the transmitting end through a D2D communication channel. And the sending end determines whether the target data fails to be sent or not according to the number of the sent data packets and the number of the received feedback information, and retransmits the corresponding data packets if the target data fails to be sent. For example, a sending end sends 100 data packets to a receiving end, and the number of ACKs sent by the receiving end to the sending end is only 98, then the sending end determines that 2 data packets have failed to be sent, and the sending end may retransmit 100 data packets until the number of ACKs fed back by the receiving end reaches 100.
For example, a transmitting end transmits 100 data packets to a receiving end, and the receiving end transmits 3 NACKs to the transmitting end within a specified time, the transmitting end determines that the transmission of the 3 data packets fails, and the transmitting end may retransmit the 100 data packets until the receiving end does not feed back a NACK within the specified time. The specified time is greater than 2 one-way data sending times, or the specified time is greater than 2 one-way data times from the time when the sending end finishes sending the last data packet. For example, if the one-way data transmission time is 30 seconds, the fixed time is 1 minute (or 2 minutes or 10 minutes) from the time when the transmitting end finishes transmitting the last data packet.
Optionally, step S120 may also be implemented by the following method: the feedback information is transmitted to a transmitting end of the device-to-device communication through a media access control (MAC CE) control element in a physical shared channel (physical shared channel psch). Alternatively, the feedback Information is transmitted to the transmitting end of the device-to-device communication through Spatial Channel Information (SCI) in a Physical control Channel (PSCCH).
In this embodiment, when receiving target data sent by the sending end, the receiving end of D2D communication can determine feedback information according to the receiving condition of the target data, and feed the feedback information back to the sending end, thereby implementing feedback of the receiving condition of the target data. In the prior art, a receiving end cannot feed back the receiving condition of the target data of the D2D communication to a sending end, so that the data transmission reliability and the quality of a server are low. In this embodiment, the receiving end of D2D communication can feed back the feedback information of the target data sent by the sending end to the sending end, so that the sending end can adjust the data sending content according to the feedback information, and reliability and service quality of data transmission in D2D communication are improved.
Example two
Fig. 2 is a flowchart of a feedback method for D2D communication according to a second embodiment of the present invention, and as a further description of the first embodiment, the method further includes:
and step S130, acquiring identification information of the target data.
When receiving the target data, the receiving end can obtain the identification information of the target data. The identification information may be a source address, a destination address, a resource pool identification (pool identity), and a resource index (TRP index) of the target data.
Specifically, a source address, a destination address, a resource pool identifier and a resource index of the target data are obtained.
Wherein, the Source address of the target data is the Identity (ID) of layer 2(layer 2) of the sending end (Source), namely Source layer 2 ID; the destination address is layer 2(layer 2) Identification (ID) of the receiving end (destination), namely destination layer 2 ID. The resource pool identifier is a resource pool identifier corresponding to a resource pool used by the sending end for sending the target data. The resource index is a resource index corresponding to a resource used in the resource pool when the sending end sends the target data.
After receiving the message corresponding to the target data, the receiving end analyzes the message header of the message to obtain the source address and the destination address of the target data. The resource pool identification and resource index used in receiving the target data are known through the PC5 interface.
Further, the length of the resource index bitmap corresponding to the target data is obtained. Because the bitmap selection of the D2D communication resource has the difference of 6 bits, 7 bits and 8 bits, the receiving end can send the length of the bitmap corresponding to the resource UI for receiving the target data to the sending end, so that the sending end can further and accurately determine the corresponding target data according to the length of the bitmap, and the retransmission efficiency is improved.
Correspondingly, step S120 of sending the feedback information to the sending end of the device-to-device communication may be implemented in the following manner:
step S120', sends the feedback information and the identification information to the sending end of the device-to-device communication.
When the identification information is the source address, the destination address, the resource pool identification and the resource index of the target data, step S120' may be implemented to send the source address, the destination address, the resource pool identification and the resource index of the target data to the sending end of the device-to-device communication.
In the first embodiment, the sending end cannot acquire which resource the transmission of the data packet sent on is wrong, and although retransmission can be achieved, the repeatability of the retransmitted data is high. In this embodiment, the sending end can narrow the range of the retransmission object according to the identification information of the target data, thereby reducing the probability that the successfully transmitted target data is retransmitted and improving the retransmission efficiency.
Further, as shown in fig. 3, step S120' can be implemented by the following steps: step S120a, sending the identification information and the feedback information to the sending end of the device-to-device communication through the mac ce in a Physical shared channel (Physical shared channel psch).
Alternatively, as shown in fig. 4, step S120' can also be implemented by the following method: step S120b, sending the identification Information and the feedback Information to the sending end of the device-to-device communication through Spatial Channel Information (SCI) in a Physical control channel (PSCCH).
The feedback information and the identification information are fed back to the sending end by using the existing signaling, so that the signaling overhead can be saved, and the resource utilization rate is improved.
Further, as shown in fig. 5, step S110, determining feedback information according to the receiving condition of the target data, may be implemented in the following manner:
step S110', determining the bit number of the feedback information according to the number of Transport Blocks (TBs) corresponding to the target data.
Each transmission block corresponds to one piece of feedback information, the feedback information is 1bit, if the feedback information is 1, the feedback information is ACK, and if the feedback information is 0, the feedback information is NACK. Illustratively, if the target data is transmitted through one transport block, the feedback information is 1 bit. If the target data is transmitted through two transmission blocks, the feedback information is 2 bit.
The feedback information is determined for each transmission block, so that the data receiving result of each transmission block can be fed back more accurately, and the accuracy of the feedback information is improved.
EXAMPLE III
Fig. 6 is a flowchart of a feedback method for device-to-device communication according to a third embodiment of the present invention, and as a further description of the foregoing embodiment, step S120 of sending feedback information to a sending end of device-to-device communication may be implemented in the following manner:
step S121, determining a feedback communication resource from the idle communication resources.
The idle communication resources may be unused communication channel resources or communication resources defined as idle from used communication resources to determined as extensive communication resources.
Further, as shown in fig. 7, step S121 may be implemented by:
step S201, at least one subframe with the value of 0 in the resource index bitmap corresponding to the physical control channel PSCCH is used as a target feedback communication resource.
The sending end sends data to the receiving end on the subframe with the value of 1 in the resource index bitmap, and does not send data in the subframe with the value of 0. In this embodiment, the bitmap receiving end sends the feedback information in the subframe with the value of 0 in the bitmap.
Step S202, a first resource pool corresponding to the target data is obtained, and communication resources corresponding to the first resource pool are used as a feedback resource pool.
Because the corresponding resource pools of the same bitmap in different resource pools are different, it is necessary to determine the feedback resource pool used by the receiving end to send the feedback information. And determining the first resource pool as a feedback resource pool if the receiving end receives the target data through the first resource pool.
Step S203 determines a second period adjacent to the first period in which the target data is received as a feedback time.
Optionally, the first period and the second period are clock periods. For example, assuming that the target data is received in clock cycle a, the feedback information is transmitted in clock cycle a + 1.
Step S204, according to a preset feedback subframe selection function and a feedback Physical Resource Block PRB index selection function, determining a target communication subframe and a target Physical Resource Block (PRB) corresponding to the target communication subframe from target reverse communication resources in a feedback Resource pool.
The preset feedback subframe selection function and the feedback PRB index selection function may be to determine a target communication subframe from subframes whose value is 0 in the bitmap according to a source address, a destination address, a resource pool identifier, a resource index, a preset cyclic shift, and a total number of RBs.
Illustratively, the target communication subframe may be calculated by the following formula:
the calculation formula of the preset feedback subframe selection function is as follows: resource pool id (pool identity) mod feeds back the total number of subframes.
The calculation formula of the feedback physical resource block PRB index selection function is as follows: (Source address (Source layer 2ID) + destination address (destination layer 2ID) + resource pool identification (pool identity) + resource index (RTP index) + n (cyclic shift)) mod Radio Bearer (RB) total number. Where mod is a modulo operation, cyclically shifting by a number of bits n, which can be given by the sender in the SCI. Optionally, n is 5 bits.
Correspondingly, step S121, sending the feedback information to the sending end of the device-to-device communication through the feedback communication resource, may be implemented as:
and when the feedback time is up, sending the feedback information to a sending end of the device-to-device communication through the target physical resource block.
Step S122, sending the feedback information to the sending end of the device-to-device communication through the feedback communication resource.
The embodiment can utilize the idle resource with the value of 0 in the bitmap to feed the feedback information of the target data back to the sending end, thereby improving the resource utilization rate.
Further, after step S204, the method further includes:
and performing code division multiplexing on the feedback information through the specified cyclic shift in the scheduling information.
The feedback information of a plurality of target data can be fed back in one subframe through code division multiplexing, and the resource utilization rate is further improved.
Further, the method also comprises the following steps: the feedback information is scrambled using the source address and/or the destination address.
The feedback information subjected to code division multiplexing can be scrambled, and the feedback information not subjected to code division multiplexing can also be scrambled.
The stability and the safety of the feedback information can be improved through scrambling.
Example four
Fig. 8 is a schematic structural diagram of a feedback apparatus for device-to-device communication according to a fourth embodiment of the present invention, where the apparatus is located at a receiving end of D2D communication, and includes:
a feedback information determining unit 11, configured to determine, when target data sent by a sending end of device-to-device communication is received, feedback information according to a receiving condition of the target data;
a sending unit 12, configured to send the feedback information determined by the feedback information determining unit 11 to a sending end of the device-to-device communication.
Further, as shown in fig. 9, the method further includes:
an identification information acquisition unit 13 configured to acquire identification information of the target data;
correspondingly, the sending unit 12 is further configured to send the feedback information determined by the feedback information determining unit 11 and the identification information obtained by the identification information obtaining unit 13 to a sending end of the device-to-device communication.
Further, the identification information obtaining unit 13 is further configured to obtain a source address, a destination address, a resource pool identifier, and a resource index of the target data;
correspondingly, the sending unit 12 further includes: and sending the source address, the destination address, the resource pool identification and the resource index of the target data to a sending end of the device-to-device communication.
Further, the identification information obtaining unit 13 is further configured to:
and acquiring the length of a resource index bitmap corresponding to the target data.
Further, the sending unit 12 is further configured to:
sending the identification information and the feedback information to a sending end of the device-to-device communication through a Media Access Control (MAC) CE in a physical shared channel (PSSCH); or,
and sending the identification information and the feedback information to a sending end of the device-to-device communication through spatial domain channel information SCI in a physical control channel PSCCH.
Further, the feedback information determining unit 11 is further configured to determine a bit number of the feedback information according to the number of the transport blocks TB corresponding to the target data.
Further, as shown in fig. 10, the transmitting unit 12 includes:
a feedback resource determining subunit 1201, configured to determine a feedback communication resource from the idle communication resources;
a sending subunit 1202, configured to send the feedback information to a sending end of the device-to-device communication through the feedback communication resource determined by the feedback resource determining subunit 1201.
Further, the feedback resource determining subunit 1201 is specifically configured to:
taking at least one subframe with the value of 0 in a resource index bitmap corresponding to a physical control channel PSCCH as a target feedback communication resource;
acquiring a first resource pool corresponding to target data, and taking communication resources corresponding to the first resource pool as a feedback resource pool;
determining a second period adjacent to the first period in which the target data is received as a feedback time;
determining a target communication subframe and a target Physical Resource Block (PRB) corresponding to the target communication subframe from the target reverse communication resources in the feedback resource pool according to a preset feedback subframe selection function and a feedback PRB index selection function;
correspondingly, the sending subunit 1202 is further configured to, when the feedback time is reached, send the feedback information to a sending end of the device-to-device communication through the target physical resource block.
Further, the sending unit 12 further includes a code division multiplexing subunit 1203,
the code division multiplexing subunit 1203 is configured to perform code division multiplexing on the feedback information through a cyclic shift specified in the scheduling information.
Further, a scrambling unit 14 is included for scrambling the feedback information using a source address and/or a destination address.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.