Methods and apparatus for sounding reference signal enhancements for subband full-duplex

1. A method of wireless communication by a user equipment (UE), comprising:

determining a change from a first uplink (UL) bandwidth pattern to a second UL bandwidth pattern occurred within a sub-band full duplex (SBFD) bandwidth;

configuring one or more settings for a sounding resource signal (SRS) transmission based on the second UL bandwidth pattern; and

transmitting, to a base station, the SRS transmission according to the one or more settings for the SRS transmission.

2. The method of claim 1 , wherein the determining of the change comprises:

determining one or more of an increase in UL bandwidth occurred, a decrease in the UL bandwidth occurred, or a change in location of a downlink (DL) signal within the SBFD bandwidth occurred.

3. The method of claim 1 , wherein the configuring of the one or more settings for the SRS transmission comprises:

configuring one or more SRS resource sets based on the second UL bandwidth pattern, wherein the SRS transmission is transmitted on an SRS resource set of the one or more SRS resource sets.

4. The method of claim 1 , wherein the configuring of the one or more settings for the SRS transmission comprises:

configuring bandwidth hopping settings for one or more SRS resource sets based on the second UL bandwidth pattern, wherein the SRS transmission is transmitted on an SRS resource set of the one or more SRS resource sets.

5. The method of claim 1 , further comprising:

activating or deactivating one or more SRS resource sets in response to the determining the change.

6. The method of claim 1 , wherein the configuring of the one or more settings for the SRS transmission comprises:

configuring the SRS transmission for non-uniform hopping bandwidths.

7. The method of claim 1 , wherein the configuring of the one or more settings for the SRS transmission comprises:

configuring the SRS transmission for non-uniform SRS symbol lengths.

8. The method of claim 1 , further comprising:

determining the second UL bandwidth pattern includes a wideband disjointed UL bandwidth pattern having a first UL bandwidth and a second UL bandwidth separated by a downlink (DL) bandwidth,

wherein the configuring of the one or more settings for the SRS transmission comprises:

configuring a resource block index setting, a guard symbol setting, a frequency hopping setting, or a simultaneous SRS transmission setting based on the wideband disjointed UL bandwidth pattern.

9. The method of claim 8 , wherein configuring the resource block index setting comprises:

excluding the DL bandwidth when counting UL resource blocks for the first UL bandwidth and the second UL bandwidth; or

considering the first UL bandwidth and the second UL bandwidth as separate active UL bandwidth patterns.

10. The method of claim 8 , wherein configuring the guard symbol setting comprises:

adding one or more guard symbols between one or more SRS transmissions in the first UL bandwidth and the second UL bandwidth; or

excluding a guard symbol based on hardware of the UE.

11. The method of claim 8 , wherein configuring the frequency hopping setting comprises:

frequency hopping from the first UL bandwidth to the second UL bandwidth after a plurality of SRS transmissions; or

frequency hopping from the first UL bandwidth to the second UL bandwidth for each SRS.

12. The method of claim 8 , wherein configuring the simultaneous SRS transmission setting comprises:

restricting simultaneous transmission of the SRS transmission in the first UL bandwidth and the second UL bandwidth; or

allowing the simultaneous transmission of the SRS transmission based on one or more capabilities of the UE.

13. A method of wireless communication by a base station, comprising:

changing a first uplink (UL) bandwidth pattern to a second UL bandwidth pattern within a sub-band full duplex (SBFD) bandwidth; and

receiving, from a user equipment (UE), a sounding reference signal (SRS) transmission based on one or more settings corresponding to the second UL bandwidth pattern.

14. The method of claim 13 , wherein the first UL bandwidth pattern changes to the second UL bandwidth pattern based on one or more of an increase in UL bandwidth, a decrease in the UL bandwidth, or a change in location of a downlink (DL) signal within the SBFD bandwidth.

15. A user equipment (UE), comprising:

a memory storing instructions; and

one or more processors coupled with the memory and configured to:

determine a change from a first uplink (UL) bandwidth pattern to a second UL bandwidth pattern occurred within a sub-band full duplex (SBFD) bandwidth;

configure one or more settings for a sounding resource signal (SRS) transmission based on the second UL bandwidth pattern; and

transmit, to a base station, the SRS transmission according to the one or more settings for the SRS transmission.

16. The UE of claim 15 , wherein the one or more processors is configured to determine the change from the first UL bandwidth pattern to the second UL bandwidth pattern based on one or more of an increase in UL bandwidth, a decrease in the UL bandwidth, or a change in location of a downlink (DL) signal within the SBFD bandwidth.

17. The UE of claim 15 , wherein the one or more processors is further configured to:

configure one or more SRS resource sets based on the second UL bandwidth pattern, wherein the SRS transmission is transmitted on an SRS resource set of the one or more SRS resource sets.

18. The UE of claim 15 , wherein the one or more processors is further configured to:

configure bandwidth hopping settings for one or more SRS resource sets based on the second UL bandwidth pattern, wherein the SRS transmission is transmitted on an SRS resource set of the one or more SRS resource sets.

19. The UE of claim 15 , wherein the one or more processors is further configured to:

activate or deactivate one or more SRS resource sets in response to the change being determined.

20. The UE of claim 15 , wherein the one or more processors is further configured to:

configure the SRS transmission for non-uniform hopping bandwidths.

21. The UE of claim 15 , wherein the one or more processors is further configured to:

configure the SRS transmission for non-uniform SRS symbol lengths.

22. The UE of claim 15 , wherein the one or more processors is further configured to:

determine the second UL bandwidth pattern includes a wideband disjointed UL bandwidth pattern having a first UL bandwidth and a second UL bandwidth separated by a downlink (DL) bandwidth, wherein the one or more settings for the SRS transmission is configured to include a resource block index setting, a guard symbol setting, a frequency hopping setting, or a simultaneous SRS transmission setting based on the wideband disjointed UL bandwidth pattern.

23. The UE of claim 22 , wherein the one or more processors is further configured to:

exclude the DL bandwidth when counting UL resource blocks for the first UL bandwidth and the second UL bandwidth; or

consider the first UL bandwidth and the second UL bandwidth as separate active UL bandwidth patterns.

24. The UE of claim 22 , wherein the one or more processors is further configured to:

add one or more guard symbols between one or more SRS transmissions in the first UL bandwidth and the second UL bandwidth; or

exclude a guard symbol based on hardware of the UE.

25. The UE of claim 22 , wherein the one or more processors is further configured to:

frequency hop from the first UL bandwidth to the second UL bandwidth after a plurality of SRS transmissions; or

frequency hop from the first UL bandwidth to the second UL bandwidth for each SRS.

26. The UE of claim 22 , wherein the one or more processors is further configured to:

restrict simultaneous transmission of the SRS transmission in the first UL bandwidth and the second UL bandwidth; or

allow the simultaneous transmission of the SRS transmission based on one or more capabilities of the UE.

27. A base station, comprising:

a memory storing instructions; and

one or more processors coupled with the memory and configured to:

change a first uplink (UL) bandwidth pattern to a second UL bandwidth pattern within a sub-band full duplex (SBFD) bandwidth; and

receive, from a user equipment (UE), a sounding reference signal (SRS) transmission based on one or more settings corresponding to the second UL bandwidth pattern.

28. The base station of claim 27 , herein the one or more processors is configured to change from the first UL bandwidth pattern to the second UL bandwidth pattern based on one or more of an increase in UL bandwidth, a decrease in the UL bandwidth, or a change in location of a downlink (DL) signal within the SBFD bandwidth.