US-12621083-B2 - Data transmission method and apparatus

US12621083B2US 12621083 B2US12621083 B2US 12621083B2US-12621083-B2

Abstract

A data transmission method and an apparatus are provided. A transmit device sends a plurality of pieces of data, wherein different data in the data occupies different transmission resources. A first receive device in a multicast group receives the data; determines a first feedback message based on a decoding result of the data; feeds back the first feedback message to the transmit device which distinguishes, based on the first feedback message, which data in the plurality of pieces of data is correctly decoded by the multicast group and which data is not, wherein the first feedback message indicates whether the first receive device correctly decodes the data; and performs network encoding transmission on the incorrectly decoded data, thereby improving retransmission efficiency, reducing a delay, and saving feedback resources.

Inventors

Zhongfeng Li
Zhe Liu

Assignees

HUAWEI TECHNOLOGIES CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20230131
Priority Date: 20200731

Claims (20)

1 . A data transmission method comprising: obtaining, by a first receive device, a plurality of pieces of data, wherein different data in the plurality of pieces of data occupies different transmission resources; determining, by the first receive device, a first feedback message based on the plurality of pieces of data, wherein the first feedback message indicates whether the first receive device correctly receives the plurality of pieces of data; outputting, by the first receive device, the first feedback message; determining, by the first receive device, a first feedback resource based on feedback content of the first feedback message, wherein the first feedback resource is comprised in a feedback resource set, and different first feedback resources in the feedback resource set correspond to different feedback content; and outputting, by the first receive device, the first feedback message on the first feedback resource.
2 . The method according to claim 1 , further comprising: receiving, by the first receive device, a first indication message, wherein the first indication message indicates a group to which the first receive device belongs in a multicast group, and the multicast group comprises a plurality of groups.
3 . The method according to claim 1 , further comprising: receiving, by the first receive device, a second indication message, wherein the second indication message indicates the first receive device to perform network encoding transmission with a second receive device.
4 . The method according to claim 1 , further comprising: listening, by the first receive device on a listener resource, to a second feedback message fed back by another receive device in a multicast group, wherein the listener resource is another resource in configured feedback resources other than the first feedback resource, and the first receive device belongs to the multicast group; and performing, by the first receive device, network encoding data retransmission based on the second feedback message.
5 . The method according to claim 1 , wherein a transmission resource comprises at least one of the following resources: a frequency resource, a time domain resource, a code domain resource, a space domain resource, and a polarization resource.
6 . The method according to claim 1 , further comprising: receiving, by the first receive device, a third indication message, wherein the third indication message indicates a redundancy version (RV) of each of the plurality of pieces of data; and determining, by the first receive device, based on the redundancy version RV of each of the plurality of pieces of data, an RV of each piece of data in response to a transmit device performing network encoding transmission.
7 . The method according to claim 1 , wherein each of the plurality of pieces of data carries a multicast identifier.
8 . A data transmission method comprising: sending, by a transmit device, a plurality of pieces of data through multicast, wherein different data in the plurality of pieces of data occupies different transmission resources; receiving, by the transmit device, a first feedback message, wherein the first feedback message indicates whether a first receive device correctly receives the plurality of pieces of data; performing, by the transmit device, network encoding transmission based on the first feedback message; and receiving, by the transmit device, a second feedback message on a second feedback resource, wherein the second feedback message indicates whether a second receive device correctly receives the plurality of pieces of data, the first feedback message is different from the second feedback message, and a first feedback resource is different from the second feedback resource.
9 . The method according to claim 8 , wherein the first feedback message occupies the first feedback resource, the first feedback resource is comprised in a feedback resource set, and different first feedback resources in the feedback resource set correspond to different feedback content.
10 . The method according to claim 8 , further comprising: receiving, by the transmit device, a second feedback message on the first feedback resource, wherein the second feedback message indicates whether a second receive device correctly receives the plurality of pieces of data, and the first feedback message is the same as the second feedback message.
11 . A communication apparatus comprising: a memory comprising processor-executable instructions; and a processor in communication with the memory, wherein the processor executes the processor-executable instructions to facilitate the apparatus to: obtain a plurality of pieces of data, wherein different data in the plurality of pieces of data occupies different transmission resources, and determine a first feedback message based on the plurality of pieces of data, wherein the first feedback message indicates whether a first receive device correctly receives the plurality of pieces of data; output the first feedback message; determine a first feedback resource based on feedback content of the first feedback message, the first feedback resource is comprised in a feedback resource set, and different first feedback resources in the feedback resource set correspond to different feedback content; and output the first feedback message on the first feedback resource.
12 . The apparatus according to claim 11 , wherein the processor further executes the processor-executable instructions to facilitate the apparatus to: receive a first indication message, wherein the first indication message indicates a group to which the first receive device belongs in a multicast group, and the multicast group comprises a plurality of groups.
13 . The apparatus according to claim 11 , wherein the processor further executes the processor-executable instructions to facilitate the apparatus to: receive a second indication message, wherein the second indication message indicates the first receive device to perform network encoding transmission with a second receive device.
14 . The apparatus according to claim 11 , wherein the processor further executes the processor-executable instructions to facilitate the apparatus to: listen, on a listener resource, to a second feedback message fed back by another receive device in a multicast group, and perform network encoded data retransmission based on the second feedback message, wherein the listener resource is another resource in configured feedback resources other than the first feedback resource, and the first receive device belongs to the multicast group.
15 . The apparatus according to claim 11 , wherein a transmission resource comprises at least one of the following resources: a frequency resource, a time domain resource, a code domain resource, a space domain resource, and a polarization resource.
16 . The apparatus according to claim 11 , wherein the processor further executes the processor-executable instructions to facilitate the apparatus to: receive a third indication message, wherein the third indication message indicates a redundancy version (RV) of each of the plurality of pieces of data; and determine, based on the RV of each of the plurality of pieces of data, an RV of each piece of data in response to a transmit device performing network encoding transmission.
17 . The apparatus according to claim 11 , wherein each of the plurality of pieces of data carries a multicast identifier.
18 . The method according to claim 10 , further comprising: sending, by the transmit device, a first indication message, wherein the first indication message indicates a group to which the first receive device belongs in a multicast group, the multicast group comprises a plurality of groups, and the first receive device and the second receive device belong to a same group in the multicast group.
19 . The method according to claim 18 , further comprising: receiving, by the transmit device, a third feedback message on a third feedback resource, wherein the third feedback message indicates whether a third receive device correctly receives the plurality of pieces of data, the first receive device belongs to a first group in the multicast group, the third receive device belongs to a second group in the multicast group, and the third feedback resource is different from the first feedback resource.
20 . The method according to claim 8 , further comprising: sending, by the transmit device, a second indication message, wherein the second indication message indicates the first receive device to perform network encoding transmission with the second receive device.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of International Application No. PCT/CN2021/104579, filed on Jul. 5, 2021, which claims priority to Chinese Patent Application No. 202010761945.0, filed on Jul. 31, 2020. The disclosures of the aforementioned applications are hereby incorporated by reference in their entireties. TECHNICAL FIELD Embodiments of this application relate to the field of communication technologies, and in particular, to a data transmission method and an apparatus. BACKGROUND In recent years, wireless communication technologies develop rapidly, and the 3rd generation mobile communication partnership project (the 3rd Generation Partner Project, 3GPP) gradually evolves to the 5th generation (5G) technology. Multicast communication is a typical communication mode proposed by the 3GPP. In the multicast communication, a transmit device sends data to a plurality of receive devices in a multicast group. After the receive device receives the data, if the receive device correctly decodes the data, the receive device feeds back an acknowledgment (ACK) message to the transmit device on a feedback resource. If the receive device fails to correctly decode the data, the receive device feeds back a negative acknowledgment (NACK) message to the transmit device on the feedback resource. After the transmit device sends data for a plurality of times, the receive device sends a feedback to the transmit device on a feedback resource corresponding to each piece of data. For the transmit device, the transmit device can learn of a feedback status of the receive device for each piece of data based on the feedback message. Therefore, the transmit device can determine, based on the feedback of the receive device, whether to perform network encoding retransmission. For example, the transmit device multicasts first data at a moment 1, and multicasts second data at a moment 2. The multicast group includes a receive device 1 and a receive device 2. The receive device 1 feeds back the ACK message for the first data, and feeds back the NACK message for the second data. The receive device 2 feeds back the NACK message for the first data, and feeds back the ACK message for the second data. The transmit device performs network encoding retransmission on the first data sent at the moment 1 through multicast and the second data sent at the moment 2 through multicast. A solution of feeding back only a NACK message (NACK only) is proposed in the industry to save feedback resources. In this solution, a receive device in a multicast group feeds back only the NACK message but does not feed back an ACK message. Each time after a transmit device sends data, provided that one receive device in the multicast group feeds back the NACK message, the transmit device considers that the multicast group fails to correctly decode the data. It is clear that, in the NACK-only solution, the transmit device cannot perform efficient network encoding retransmission. SUMMARY Embodiments of this application provide a data transmission method and an apparatus. A receive device performs joint HARQ feedback on a plurality of pieces of data sent by a transmit device through multicast, so that the transmit device can distinguish data that is in the data and that is not correctly decoded by a multicast group, and the transmit device performs network encoding transmission. In this way, retransmission efficiency is improved and feedback resources are saved. According to a first aspect, an embodiment of this application provides a data transmission method. The method is applied to a first receive device or a chip in the first receive device. The following describes the method by using an example in which the method is applied to the first receive device. The method includes: A transmit device sends a plurality of pieces of data through multicast, where different data in the data occupies different transmission resources. The first receive device in a multicast group receives the data, and determines a first feedback message based on a decoding result of the data. The first feedback message indicates whether the first receive device correctly decodes the data. The first receive device feeds back the first feedback message to the transmit device. The transmit device can distinguish, based on the first feedback message, which data in the plurality of pieces of data is correctly decoded by the multicast group and which data is not correctly decoded by the multicast group, to perform network encoding transmission on the data that is in the plurality of pieces of data and that is not correctly received by the multicast group. In this way, retransmission efficiency is improved, a delay is reduced, and feedback resources are saved. Further, when the transmit device performs network encoding transmission, data with a high priority is selected from the data that is not correctly received, and network encoding transmission is preferential