EP-4738909-A1 - TRANSMISSION METHOD AND RELATED APPARATUS

EP4738909A1EP 4738909 A1EP4738909 A1EP 4738909A1EP-4738909-A1

Abstract

This application discloses a transmission method and a related apparatus. The transmission method includes: A terminal device receives first indication information, where the first indication information indicates the terminal device to switch from a first communication mode to a second communication mode, the first communication mode indicates that the terminal device communicates with a plurality of transmission nodes separately by using a plurality of beams, and the second communication mode indicates that the terminal device communicates with a single transmission node by using a single beam; the terminal device determines a first beam based on the first indication information; and the terminal device measures or transmits a reference signal based on the first beam, or transmits a channel based on the first beam. This can reduce a waste of resources and reduce overheads.

Inventors

LI, FANG
FAN, BO
YUAN, Shitong

Assignees

Huawei Technologies Co., Ltd.

Dates

Publication Date: 20260506
Application Date: 20240731

Claims (20)

A transmission method, comprising: receiving, by a terminal device, first indication information, wherein the first indication information indicates the terminal device to switch from a first communication mode to a second communication mode, the first communication mode indicates that the terminal device communicates with a plurality of transmission nodes separately by using a plurality of beams, and the second communication mode indicates that the terminal device communicates with a single transmission node by using a single beam; determining, by the terminal device, a first beam based on the first indication information; and measuring or transmitting, by the terminal device, a reference signal based on the first beam, or transmitting a channel based on the first beam.
The method according to claim 1, wherein the reference signal comprises a channel state information-reference signal CSI-RS, the plurality of beams are respectively associated with a plurality of CSI-RS sets, each CSI-RS set comprises a plurality of CSI-RSs, and the measuring, by the terminal device, the reference signal based on the first beam comprises: determining, by the terminal device from the plurality of CSI-RS sets, a first CSI-RS set associated with the first beam; and measuring, by the terminal device, only the first CSI-RS set to obtain a first measurement result.
The method according to claim 2, wherein before the receiving, by the terminal device, the first indication information, the method further comprises: receiving, by the terminal device, first configuration information, wherein the first configuration information indicates the terminal device to report a second measurement result of K groups of CSI-RSs, K is greater than or equal to 0, a second measurement result of each group of CSI-RSs comprises at least two CSI-RSs, and the at least two CSI-RSs are from different CSI-RS sets; and after the terminal device switches from the first communication mode to the second communication mode, reporting, by the terminal device, only the first measurement result, wherein the first measurement result comprises a second measurement result of M CSI-RSs, the M CSI-RSs for the second measurement result are all from the first CSI-RS set, and M is greater than or equal to 0.
The method according to claim 1, wherein the reference signal comprises a channel state information-reference signal CSI-RS, a CSI-RS set comprises a plurality of CSI-RS groups and one or more CSI-RS resource pairs, each CSI-RS group comprises a plurality of CSI-RSs, CSI-RSs in the plurality of CSI-RS groups are associated with the plurality of beams, the CSI-RS resource pair comprises one CSI-RS from each CSI-RS group, and the measuring, by the terminal device, the reference signal based on the first beam comprises: determining, by the terminal device from the CSI-RS set, a CSI-RS associated with the first beam; and measuring, by the terminal device, only the CSI-RS associated with the first beam, to obtain a third measurement result.
The method according to claim 4, wherein before the receiving, by the terminal device, the first indication information, the method further comprises: receiving, by the terminal device, second configuration information, wherein the second configuration information indicates the terminal device to report a fourth measurement result of X CSI-RSs, X is greater than or equal to 0, and/or the second configuration information indicates the terminal device to report a fifth measurement result of one CSI-RS resource pair; and after the terminal device switches from the first communication mode to the second communication mode, reporting, by the terminal device, only the third measurement result.
The method according to any one of claims 1 to 5, wherein the reference signal comprises a sounding reference signal SRS, the plurality of beams are respectively associated with a plurality of SRS sets, and the transmitting, by the terminal device, the reference signal based on the first beam comprises: determining, by the terminal device from the plurality of SRS sets, an SRS set associated with the first beam; and sending, by the terminal device, only the SRS set associated with the first beam.
The method according to any one of claims 1 to 6, wherein the channel comprises a physical downlink shared channel PDSCH scheduled by a format of first downlink control information DCI, and the transmitting, by the terminal device, the channel based on the first beam comprises: receiving, by the terminal device, the first DCI, wherein the first DCI is used for scheduling the PDSCH; and receiving, by the terminal device by using the first beam, the PDSCH scheduled by the format of the first DCI.
The method according to claim 7, further comprising: the first DCI comprises a first field, and the first field indicates that the terminal device is in the second communication mode, or the first field indicates that the terminal device receives the PDSCH by using the first beam; and receiving, by the terminal device by using the first beam, the PDSCH scheduled by the format of the first DCI.
The method according to any one of claims 1 to 8, wherein the channel comprises a physical uplink shared channel PUSCH scheduled by a format of second downlink control information DCI, and the transmitting, by the terminal device, the channel based on the first beam comprises: receiving, by the terminal device, the second DCI, wherein the second DCI is used for scheduling the PUSCH; and sending, by the terminal device by using the first beam, the PUSCH scheduled by the format of the second DCI.
The method according to claim 9, further comprising: the second DCI comprises a second field, and the second field indicates that the terminal device is in the second communication mode, or the second field indicates that the terminal device sends the PUSCH by using the first beam; and sending, by the terminal device by using the first beam, the PUSCH scheduled by the format of the second DCI.
The method according to any one of claims 1 to 10, wherein the first indication information comprises a medium access control control element MAC CE.
The method according to claim 11, wherein the first indication information further comprises third downlink control information DCI, the third DCI indicates the terminal device to communicate with the single transmission node by using the first beam, and the determining, by the terminal device, the first beam based on the first indication information comprises: switching, by the terminal device, from the first communication mode to the second communication mode based on the MAC CE; and determining, by the terminal device, the first beam based on the third DCI.
The method according to any one of claims 1 to 12, wherein the plurality of transmission nodes comprise a first transmission node and a second transmission node, the transmission node is associated with a first timing advance TA, the first indication information is used to activate one or more beams associated with the transmission node, and the one or more beams associated with the transmission node are all associated with the first TA.
The method according to claim 13, wherein the second transmission node is associated with a second TA, and the method further comprises: stopping, by the terminal device, a timer corresponding to the second TA; stopping, by the terminal device, a random access channel RACH procedure corresponding to the second TA; clearing, by the terminal device, sending of an uplink physical channel or an uplink reference signal corresponding to the second TA; and clearing, by the terminal device, a hybrid automatic repeat request HARQ buffer corresponding to the second TA.
The method according to any one of claims 1 to 14, wherein an effective condition for the terminal device to switch from the first communication mode to the second communication mode is: after a first time period in which the terminal device receives the first indication information and feeds back acknowledgment information to the network device.
The method according to any one of claims 1 to 15, wherein the first communication mode is a multiple transmission and reception point mTRP mode, and the second communication mode is a single transmission and reception point sTRP mode.
A transmission method, comprising: sending first indication information to a terminal device, wherein the first indication information indicates the terminal device to switch from a first communication mode to a second communication mode, the first communication mode indicates that the terminal device communicates with a plurality of transmission nodes separately by using a plurality of beams, and the second communication mode indicates that the terminal device communicates with a single transmission node by using a single beam; and receiving a measurement result of a reference signal from the terminal device, or transmitting a reference signal or a channel.
The method according to claim 17, wherein the reference signal comprises a channel state information-reference signal CSI-RS, the plurality of beams are respectively associated with a plurality of CSI-RS sets, each CSI-RS set comprises a plurality of CSI-RSs, and before the sending the first indication information to the terminal device, the method further comprises: sending first configuration information to the terminal device, wherein the first configuration information indicates the terminal device to report a second measurement result of K groups of CSI-RSs, K is greater than or equal to 0, a second measurement result of each group of CSI-RSs comprises at least two CSI-RSs, and the at least two CSI-RSs are from different CSI-RS sets; and after the sending the first indication information to the terminal device, the receiving the measurement result of the reference signal from the terminal device comprises: receiving a first measurement result from the terminal device, wherein the first measurement result comprises a second measurement result of M CSI-RSs, the M CSI-RSs for the second measurement result are all from the first CSI-RS set, and M is greater than or equal to 0.
The method according to claim 17, wherein the reference signal comprises a channel state information-reference signal CSI-RS, a CSI-RS set comprises a plurality of CSI-RS groups and one or more CSI-RS resource pairs, each CSI-RS group comprises a plurality of CSI-RSs, CSI-RSs in the plurality of CSI-RS groups are associated with the plurality of beams, the CSI-RS resource pair comprises one CSI-RS from each CSI-RS group, and before the sending the first indication information to the terminal device, the method further comprises: sending second configuration information to the terminal device, wherein the second configuration information indicates the terminal device to report a fourth measurement result of X CSI-RSs, X is greater than or equal to 0, and/or the second configuration information indicates the terminal device to report a fifth measurement result of one CSI-RS resource pair; and after the sending the first indication information to the terminal device, the receiving the measurement result of the reference signal from the terminal device comprises: receiving a third measurement result from the terminal device, wherein the third measurement result is a result of measuring, by the terminal device, only a CSI-RS associated with the first beam.
The method according to any one of claims 17 to 19, wherein the reference signal comprises a sounding reference signal SRS, the plurality of beams are respectively associated with a plurality of SRS sets, and the transmitting the reference signal comprises: receiving an SRS set associated with the first beam.

Description

This application claims priority to Chinese Patent Application No. 202311021451.9, filed with the China National Intellectual Property Administration on August 11, 2023 and entitled "TRANSMISSION METHOD AND RELATED APPARATUS", which is incorporated herein by reference in its entirety. TECHNICAL FIELD This application relates to the field of communication technologies, and in particular, to a transmission method and a related apparatus. BACKGROUND In a communication system, a plurality of transmission nodes can simultaneously communicate with one terminal device. The plurality of transmission nodes need to indicate a plurality of beams to the terminal device, and each of the plurality of transmission nodes communicates with the terminal device by using one beam. When the terminal device is indicated to communicate with a single transmission node by using a single beam, if the terminal device performs communication still based on beam information corresponding to the plurality of transmission nodes, resources are wasted. SUMMARY This application provides a transmission method and a related apparatus, to reduce a waste of resources and reduce overheads. According to a first aspect, this application provides a transmission method. The method can be applied to the field of communication technologies and includes: First, a terminal device receives first indication information, where the first indication information indicates the terminal device to switch from a first communication mode to a second communication mode, the first communication mode indicates that the terminal device communicates with a plurality of transmission nodes separately by using a plurality of beams, and the second communication mode indicates that the terminal device communicates with a single transmission node by using a single beam; then the terminal device determines a first beam based on the first indication information; and finally the terminal device measures or transmits a reference signal based on the first beam, or transmits a channel based on the first beam. In this application, after receiving the first indication information sent by a network device, the terminal device may switch from the first communication mode to the second communication mode according to the indication of the first indication information, and transmit the reference signal or the channel based on the first beam associated with the single transmission node. This reduces a waste of resources and reduces overheads. In addition, after switching is performed from the first communication mode to the second communication mode, the reference signal or the channel is transmitted directly based on beam information associated with the single transmission node. This omits a beam information reconfiguration procedure and further reduces a transmission delay, compared with a case in which a reference signal or a channel can be transmitted only after associated beam information is reconfigured for a transmission node. In a possible implementation, the reference signal includes a channel state information-reference signal (channel state information-reference signal, CSI-RS), the plurality of beams are respectively associated with a plurality of CSI-RS sets, and each CSI-RS set includes a plurality of CSI-RSs. Before receiving the first indication information, the terminal device receives first configuration information, where the first configuration information indicates the terminal device to report a second measurement result of K groups of CSI-RSs, K is greater than or equal to 0, a second measurement result of each group of CSI-RSs includes at least two CSI-RSs, and the at least two CSI-RSs are from different CSI-RS sets; after receiving the first indication information and determining the first beam based on the first indication information, the terminal device determines, from the plurality of CSI-RS sets, a first CSI-RS set associated with the first beam, and the terminal device measures only the first CSI-RS set to obtain a first measurement result; andafter the terminal device switches from the first communication mode to the second communication mode, the terminal device reports only the first measurement result, where the first measurement result includes a second measurement result of M CSI-RSs, the M CSI-RSs for the second measurement result are all from the first CSI-RS set, and M is greater than or equal to 0. In this implementation, before receiving the first indication information, the terminal device receives the first configuration information. The first configuration information indicates content that is indicated to be reported when the terminal device operates in the first communication mode. When the terminal device operates in the first communication mode, the terminal device may communicate with the network device through the plurality of transmission nodes. Therefore, the first configuration information indicates that the second measurement result