US-12621818-B2 - Beam failure recovery method and apparatus

Abstract

This application provides a beam failure recovery method and an apparatus to reduce implementation complexity of a terminal in a BFR procedure. The method includes: A terminal receives configuration information sent by a network device, where the configuration information is used to indicate one or more uplink signal resources; the terminal sends an uplink signal based on the configuration information, and the network device measures the uplink signal and determines beam quality of an uplink resource corresponding to the uplink signal; and the network device sends a first response message to the terminal based on a measurement result of the uplink signal when a beam failure occurs, so that the terminal determines that a beam failure recovery succeeds. The technical solutions in this application are applicable to the BFR procedure.

Inventors

• Tie Li
• Yongping Zhang
• Xi Zhang

Assignees

• HUAWEI TECHNOLOGIES CO., LTD.

Dates

Publication Date

20260505

Application Date

20220208

Priority Date

20190809

Claims (20)

1. 1 . A beam failure recovery method, comprising: receiving configuration information sent by a network device, wherein the configuration information is used to indicate M uplink signal resources, and M is a positive integer; sending an uplink signal based on the configuration information; sending, by a terminal, a first request message when a beam failure occurs, wherein the first request message is used to request a beam failure recovery; and receiving, from the network device, a first response message based on a measurement result of the uplink signal by the network device when a beam failure occurs, wherein the first response message is used to determine that a beam failure recovery succeeds.
2. 2 . The beam failure recovery method according to claim 1 , wherein the uplink signal resource is a sounding reference signal (SRS) resource.
3. 3 . The beam failure recovery method according to claim 2 , wherein the SRS resource is an SRS resource used for antenna selection, an SRS resource used for physical uplink shared channel transmission, an SRS resource used for beam management, or an SRS resource used for new beam detection.
4. 4 . The beam failure recovery method according to claim 1 , wherein sending the first request message comprises sending the first request message before the sending an uplink signal based on the configuration information.
5. 5 . The beam failure recovery method according to claim 1 , wherein sending the first request message comprises sending the first request message after the sending an uplink signal based on the configuration information.
6. 6 . The beam failure recovery method according to claim 1 , wherein when the terminal accesses one serving cell, the sending an uplink signal based on the configuration information comprises: sending the uplink signal based on the M uplink signal resources.
7. 7 . The beam failure recovery method according to claim 4 , wherein the first request message comprises first indication information, and the first indication information is used to indicate that a beam failure occurs in a serving cell.
8. 8 . A communication apparatus, comprising: a processor and a memory connected to the processor, wherein the communication apparatus is terminal, and the memory is configured to store computer-executable instructions, and the processor executes the computer-executable instructions stored in the memory, to enable the apparatus to implement: receiving configuration information sent by a network device, wherein the configuration information is used to indicate M uplink signal resources, and M is a positive integer; sending an uplink signal based on the configuration information; sending a first request message when a beam failure occurs, wherein the first request message is used to request a beam failure recovery; and receiving, from the network device, a first response message based on a measurement result of the uplink signal by the network device when a beam failure occurs, wherein the first response message is used to determine that a beam failure recovery succeeds.
9. 9 . The communication apparatus according to claim 8 , wherein the uplink signal resource is a sounding reference signal (SRS) resource.
10. 10 . The communication apparatus according to claim 9 , wherein the SRS resource is an SRS resource used for antenna selection, an SRS resource used for physical uplink shared channel transmission, an SRS resource used for beam management, or an SRS resource used for new beam detection.
11. 11 . The communication apparatus according to claim 8 , wherein to enable the apparatus to implement: sending the first request message when a beam failure occurs before sending the uplink signal.
12. 12 . The communication apparatus according to claim 8 , wherein to enable the apparatus to implement: sending the first request message when a beam failure occurs after sending the uplink signal.
13. 13 . The communication apparatus according to claim 8 , wherein to enable the apparatus to implement: sending the uplink signal based on the M uplink signal resources when the terminal accesses one serving cell.
14. 14 . The communication apparatus according to claim 11 , wherein the first request message comprises first indication information, and the first indication information is used to indicate that a beam failure occurs in a serving cell.
15. 15 . A communication apparatus, comprising: a processor and a memory connected to the processor, wherein the communication apparatus is a network device, and the memory is configured to store computer-executable instructions, and the processor executes the computer-executable instructions stored in the memory, to enable the apparatus to implement: sending configuration information to a terminal, wherein the configuration information is used to indicate M uplink signal resources, and M is a positive integer; receiving an uplink signal from the terminal based on the configuration information; receiving, from the terminal, a first request message when a beam failure occurs, wherein the first request message is used to request a beam failure recovery; measuring an uplink signal based on the configuration information; determining whether a beam failure recovery succeeds based on a measurement result of the uplink signal; and sending, to the terminal, a first response message to the terminal based on the measurement result of the uplink signal and the receipt of the first request message, wherein the first response message is used to enable the terminal to determine that the beam failure recovery succeeds.
16. 16 . The communication apparatus according to claim 15 , wherein the uplink signal resource is a sounding reference signal (SRS) resource.
17. 17 . The communication apparatus according to claim 16 , wherein the SRS resource is an SRS resource used for antenna selection, an SRS resource used for physical uplink shared channel transmission, an SRS resource used for beam management, or an SRS resource used for new beam detection.
18. 18 . The communication apparatus according to claim 15 , wherein to enable the apparatus to implement: receiving the first request message sent by the terminal before measuring the uplink signal.
19. 19 . The communication apparatus according to claim 15 , wherein to enable the apparatus to implement: receiving a first request message sent by the terminal after measuring the uplink signal.
20. 20 . The communication apparatus according to claim 15 , wherein to enable the apparatus to implement: measuring the uplink signal based on the M uplink signal resources when the terminal accesses one serving cell.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of International Application No. PCT/CN2020/107911, filed on Aug. 7, 2020, which claims priority to Chinese Patent Application No. 201910736673.6, filed on Aug. 9, 2019. The disclosures of the aforementioned applications are hereby incorporated by reference in their entireties. TECHNICAL FIELD This application relates to the field of communication technologies, and in particular, to a beam failure recovery method and an apparatus. BACKGROUND Compared with a long term evolution (long term evolution, LTE) communication system that uses a low frequency band, a high frequency band is added to a fifth generation (5th generation, 5G) new radio (new radio, NR) communication system to implement a larger bandwidth and a higher transmission rate. When a frequency of a signal is high, the signal suffers severe fading during spatial propagation. Therefore, a hybrid beamforming technology is used in the 5G NR communication system to improve a directional power in a transmission direction, to obtain a good directional gain, improve a signal-to-interference-noise ratio at a receive end, and further improve performance of the 5G NR communication system. In the 5G NR communication system, because both a base station and a terminal use a hybrid beamforming technology, beam management needs to be performed between the terminal and the base station. By using an uplink and downlink beam management function, the base station and the terminal may align a transmit beam with a receive beam, thereby ensuring normal communication on a transmit link and a receive link between the base station and the terminal. To ensure robustness of the transmit link and the receive link, two functions are further defined in a 5G protocol: a radio link failure (radio link failure, RLF) and a beam failure recovery (beam failure recovery, BFR). The RLF is used to declare a cell-level radio link failure. The BFR is used to declare that a beam failure occurs in a current cell. The BFR is designed to quickly recover, by using a BFR procedure before the RLF is triggered, from a radio link failure caused by a beam failure. For the BFR, the base station configures a new beam candidate set for the terminal. The new beam candidate set includes a plurality of downlink reference signal resources, for example, channel state information-reference signal (channel state information-reference signal, CSI-RS) resources. In this way, when a beam of the serving cell fails, the terminal determines beam quality corresponding to each downlink reference signal resource in the new beam candidate set of the serving cell, and then selects an available beam and reports the available beam to the base station to implement a beam recovery. Currently, in the BFR procedure, the terminal needs to measure signals carried by the plurality of downlink reference signal resources in the new beam candidate set, to determine the beam quality corresponding to each downlink reference signal resource in the new beam candidate set. This increases implementation complexity of the terminal in the BFR procedure. SUMMARY Embodiments of this application provide a beam failure recovery method and an apparatus to reduce implementation complexity of a terminal in a BFR procedure. According to a first aspect, a beam failure recovery method is provided. The method includes: A terminal receives configuration information sent by a network device, where the configuration information is used to indicate M uplink signal resources, and M is a positive integer; the terminal sends an uplink signal based on the configuration information; and the terminal receives a first response message based on the uplink signal when a beam failure occurs, where the first response message is used to determine that a BFR succeeds. Based on the foregoing technical solution, the terminal receives the configuration information sent by the network device to learn of the plurality of uplink signal resources. In this way, the terminal may send the uplink signal based on the configuration information, and the network device measures the uplink signal to determine beam quality of the plurality of uplink signal resources. Based on beam reciprocity, after the network device finishes measuring an uplink, the network device may determine a transmit beam, used for a downlink, of the network device. In addition, the terminal can determine, based on an indication of the network device, a receive beam, used for the downlink, of the terminal. Therefore, when a beam failure occurs, the terminal receives the first response message sent by the network device based on the uplink signal, to complete a beam failure recovery. As can be learned, in the technical solution provided in this embodiment of this application, the terminal does not need to measure a downlink reference signal to determine beam quality of a plurality of downlink reference signal resources, thereby reducing