Signal transmission method, related apparatus, and system

1. A signal transmission method, comprising:

receiving, by a first device, resource configuration information from a second device, wherein the resource configuration information is for a reference signal that indicates a measure of interference between a first link and a second link, wherein the first link is a link between the first device and a fourth device, the second link is a link between the second device and a third device, and the first device and the second device are relay nodes between the third device and the fourth device;

sending or receiving, by the first device, the reference signal on a reference signal resource indicated by the resource configuration information;

measuring, by the first or second device, the interference between the first link and the second link; and

sending, by the first device, first reporting information to the second device, wherein the first reporting information indicates whether the first device has a multi-link beam correspondence capability;

wherein the multi-link beam correspondence capability comprises a capability of the first device to send or receive, on the first link and a third link, reference signals on antenna ports having a quasi co-location (QCL) relationship or a capability of the first device to send or receive reference signals on the first link and a third link by using a same beam or a same spatial filter; and

wherein the third link is a link between the second device and the first device.

2. The method according to claim 1 , wherein sending or receiving the reference signal comprises sending or receiving, by the first device, the reference signal on the first link based on the resource configuration information.

3. The method according to claim 1 , further comprising receiving, by the first device, first indication information from the second device, wherein the first indication information indicates that the reference signal indicates a measure of interference of a downlink transmission on the first link to a downlink transmission on the second link, or that the first device is to send the reference signal on the reference signal resource indicated by the resource configuration information.

4. The method according to claim 1 , further comprising receiving, by the first device, first indication information from the second device, wherein the first indication information indicates that the reference signal indicates a measure of interference of an uplink transmission on the second link to an uplink transmission on the first link, or that the first device is to send the reference signal on the reference signal resource indicated by the resource configuration information.

5. The method according to claim 1 , wherein the resource configuration information comprises indication information of a measurement type corresponding to the reference signal and wherein the measurement type comprises a measurement of the interference of a downlink transmission on the first link to a downlink transmission on the second link or a measurement of the interference of an uplink transmission on the second link to an uplink transmission on the first link.

6. The method according to claim 1 , wherein the reference signal resource indicated by the resource configuration information is associated with a measurement type that comprises a measurement of interference of a downlink transmission on the first link to a downlink transmission on the second link or a measurement of interference of an uplink transmission on the second link to an uplink transmission on the first link.

7. A communications apparatus, comprising:

at least one processor; and

a memory coupled to the at least one processor, the memory storing instructions that when executed by the at least one processor cause the at least one processor to:

receive resource configuration information from a second device, wherein the resource configuration information is for a reference signal that indicates a measure of interference between a first link and a second link;

send or receive the reference signal on a reference signal resource indicated by the resource configuration information; and

measure the interference between the first link and the second link, wherein the first link is a link between the communications apparatus and a fourth device, the second link is a link between the second device and a third device, and the communications apparatus and the second device are relay nodes between the third device and the fourth device; and

sending first reporting information to the second device;

wherein the first reporting information indicates whether the communications apparatus has a multi-link beam correspondence capability;

wherein the multi-link beam correspondence capability comprises a capability of the communications apparatus to send or receive, on the first link and a third link, reference signals on antenna ports having a quasi co-location (QCL) relationship or a capability of the communications apparatus to send or receive reference signals on the first link and a third link by using a same beam or a same spatial filter; and

wherein the third link is a link between the second device and the communications apparatus.

8. The communications apparatus according to claim 7 , wherein the at least one processor is configured to send or receive the reference signal on the first link based on the resource configuration information.

9. The communications apparatus according to claim 7 , wherein the at least one processor is further configured to receive first indication information from the second device, wherein the first indication information indicates that the reference signal indicates a measure of interference of a downlink transmission on the first link to a downlink transmission on the second link, or that the communications apparatus is to send the reference signal on the resource indicated by the resource configuration information.

10. The communications apparatus according to claim 7 , wherein the at least one processor is further configured to receive first indication information from the second device, wherein the first indication information indicates that the reference signal indicates a measure of interference of an uplink transmission on the second link to an uplink transmission on the first link, or that the communications apparatus is to receive the reference signal on a configured resource indicated by the resource configuration information.

11. The communications apparatus according to claim 7 , wherein the resource configuration information comprises indication information of a measurement type corresponding to the reference signal and wherein the measurement type comprises a measurement of the interference of a downlink transmission on the first link to a downlink transmission on the second link, or a measurement of the interference of an uplink transmission on the second link to an uplink transmission on the first link.

12. The communications apparatus according to claim 7 , wherein the reference signal resource indicated by the resource configuration information is associated with a measurement type and wherein the measurement type comprises a measurement of interference of a downlink transmission on the first link to a downlink transmission on the second link, or a measurement of interference of an uplink transmission on the second link to an uplink transmission on the first link.

13. A communication system, comprising:

a first device; and

a second device;

wherein the first device is configured to:

receive resource configuration information from the second device, wherein the resource configuration information is for a reference signal that indicates a measure of interference between a first link and a second link, wherein the first link is a link between the first device and a fourth device, the second link is a link between the second device and a third device, and the first device and the second device are relay nodes between the third device and the fourth device;

send or receive the reference signal on a reference signal resource indicated by the resource configuration information; and

measure the interference between the first link and the second link;

sending, by the first device, first reporting information to the second device, wherein the first reporting information indicates whether the first device has a multi-link beam correspondence capability;

wherein the multi-link beam correspondence capability comprises a capability of the first device to send or receive, on the first link and a third link, reference signals on antenna ports having a quasi co-location (QCL) relationship or a capability of the first device to send or receive reference signals on the first link and a third link by using a same beam or a same spatial filter; and

wherein the third link is a link between the second device and the first device and

wherein the second device is configured to:

send the resource configuration information to the first device; and

send or receive the reference signal on a resource indicated by the resource configuration information.

14. The system according to claim 13 , wherein the first device is configured to send or receive the reference signal on the first link based on the resource configuration information and the second device is configured to receive or send the reference signal on the second link.

15. The system according to claim 13 , wherein the first device is further configured to receive first indication information from the second device and the second device is further configured to send the first indication information to the first device, wherein the first indication information indicates that the reference signal indicates a measure of interference of a downlink transmission on the first link to a downlink transmission on the second link, or that the first device is to send the reference signal on the reference signal resource indicated by the resource configuration information.

16. The system according to claim 13 , wherein the first device is further configured to receive first indication information from the second device and the second device is further configured to send the first indication information to the first device, wherein the first indication information indicates that the reference signal indicates a measure of interference of an uplink transmission on the second link to an uplink transmission on the first link, or that the first device is to receive the reference signal on the reference signal resource indicated by the resource configuration information.

17. The system according to claim 13 , wherein the resource configuration information comprises indication information of a measurement type corresponding to the reference signal and wherein the measurement type comprises a measurement of the interference of a downlink transmission on the first link to a downlink transmission on the second link, or a measurement of the interference of an uplink transmission on the second link to an uplink transmission on the first link.

18. The system according to claim 13 , wherein the reference signal resource indicated by the resource configuration information for the reference signal is associated with a measurement type and wherein the measurement type comprises a measurement of interference of a downlink transmission on the first link to a downlink transmission on the second link, or a measurement of interference of an uplink transmission on the second link to an uplink transmission on the first link.