SRS optimization for coordinated multi-point transmission and reception

Patent metadata

Field	Value
Publication number	US-9900849-B2
Application number	US-201213633667-A
Country	US
Kind code	B2
Filing date	Oct 2, 2012
Priority date	Oct 3, 2011
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

Certain aspects of the present disclosure relate to techniques for power control and SRS multiplexing for coordinated multi-point (CoMP) transmission and reception in heterogeneous networks (HetNet). Multiple SRS processes are supported with different physical and/or virtual cell ID. Different power control offsets and processes are associated with the different SRS processes.

First claim

What is claimed is:

1. A method for wireless communication by a user equipment (UE), comprising:
transmitting a first sounding reference signal (SRS) intended for a first one or more base stations currently serving the UE and associated with a first cell identifier;
transmitting a second SRS intended for a second one or more base stations associated with a second cell identifier; and
adjusting, a based on one or more transmit power control (TPC) commands, a transmission power of the first and the second SRS with different power control schemes.

2. The method of claim 1 , wherein the UE is configured to transmit at least one of the first and second SRS periodically.

3. The method of claim 1 , wherein the UE is configured to transmit at least one of the first and second SRS aperiodically.

4. The method of claim 1 , wherein adjusting the transmission power of the first and the second SRS with different power control schemes comprises:
adjusting the first SRS with a first power control scheme; and
adjusting the second SRS with a second power control scheme, wherein the first power control scheme results in the first SRS being transmitted with a different power offset than the second SRS.

5. The method of claim 4 , wherein the first power control scheme utilizes an outer power control loop with TPC commands from a base station.

6. The method of claim 5 , wherein the second power control scheme does not utilize an outer power control loop.

7. The method of claim 5 , wherein the TPC commands of the first power control scheme are different from TPC commands applied to physical uplink channels in which the first SRS is not transmitted.

8. The method of claim 1 , wherein:
the second cell identifier comprises a virtual cell identifier associated with a plurality of base stations participating in coordinated multipoint (CoMP) operations with the UE.

9. The method of claim 1 , wherein the second cell identifier comprises a cell identifier associated with a neighboring cell.

10. A method for wireless communication by a first base station, comprising:
configuring a user equipment (UE) to transmit a first sounding reference signal (SRS) intended for a first one or more base stations currently serving the UE and associated with a first cell identifier;
configuring the UE to transmit a second SRS intended for a second one or more base stations associated with a second cell identifier; and
sending one or more transmit power control (TPC) commands for the UE to adjust a transmission power of the first and the second SRS with different power control schemes.

11. The method of claim 10 , wherein the UE is configured to transmit at least one of the first and second SRS periodically.

12. The method of claim 10 , wherein the UE is configured to transmit at least one of the first and second SRS aperiodically.

13. The method of claim 10 , wherein the one or more TPC commands comprise TPC commands utilized in an outer power control loop of a first power control scheme.

14. The method of claim 13 , wherein the one or more TPC commands further comprise separate TPC commands utilized in an outer power control loop of a second power control scheme.

15. The method of claim 13 , further comprising:
transmitting TPC commands applied by the UE to adjust transmit power of one or more physical uplink channels in which the first SRS is not transmitted.

16. The method of claim 10 , wherein:
the second cell identifier comprises a virtual cell identifier associated with a plurality of base stations participating in coordinated multipoint (CoMP) operations with the UE.

17. The method of claim 10 , wherein the second cell identifier comprises a cell identifier associated with a neighboring cell.

18. An apparatus for wireless communication by a user equipment (UE), comprising:
means for transmitting a first sounding reference signal (SRS) intended for a first one or more base stations currently serving the UE and associated with a first cell identifier;
means for transmitting a second SRS intended for a second one or more base stations associated with a second cell identifier; and
means for adjusting, based on one or more transmit power control (TPC) commands, a transmission power of the first and the second SRS with different power control schemes.

19. The apparatus of claim 18 , wherein the UE is configured to transmit at least one of the first and second SRS periodically.

20. The apparatus of claim 18 , wherein the UE is configured to transmit at least one of the first and second SRS aperiodically.

21. The apparatus of claim 18 , wherein adjusting the transmission power of the first and the second SRS with different power control schemes comprises:
adjusting the first SRS with a first power control scheme; and
adjusting the second SRS with a second power control scheme, wherein the first power control scheme results in the first SRS being transmitted with a power offset than the second SRS.

22. The apparatus of claim 21 , wherein the first power control scheme utilizes an outer power control loop with TPC commands from a base station.

23. The apparatus of claim 22 , wherein the second power control scheme does not utilize an outer power control loop.

24. The apparatus of claim 22 , wherein the TPC commands of the first power control scheme are different from TPC commands applied to physical uplink channels in which the first SRS is not transmitted.

25. The apparatus of claim 18 , wherein:
the second cell identifier comprises a virtual cell identifier associated with a plurality of base stations participating in coordinated multipoint (CoMP) operations with the UE.

26. The apparatus of claim 18 , wherein the second cell identifier comprises a cell identifier associated with a neighboring cell.

27. An apparatus for wireless communication by a first base station, comprising:
means for configuring a user equipment (UE) to transmit a first sounding reference signal (SRS) intended for a first one or more base stations currently serving the UE and associated with a first cell identifier;
means for configuring the UE to transmit a second SRS intended for a second one or more base stations associated with a second cell identifier; and
means for sending one or more transmit power control (TPC) commands for the UE to adjust a transmission power of the first and the second SRS with different power control schemes.

28. The apparatus of claim 27 , wherein the UE is configured to transmit at least one of the first and second SRS periodically.

29. The apparatus of claim 27 , wherein the UE is configured to transmit at least one of the first and second SRS aperiodically.

30. The apparatus of claim 27 , wherein the one or more TPC commands comprise TPC commands utilized in an outer power control loop of a first power control scheme.

31. The apparatus of claim 30 , wherein the one or more TPC commands further comprise separate TPC commands utilized in an outer power control loop of a second power control scheme.

32. The apparatus of claim 30 , further comprising: means for transmitting TPC commands applied by the UE to adjust transmit power of one or more physical uplink channels in which the first SRS is not transmitted.

33. The apparatus of claim 27 , wherein:
the second cell identifier

Assignees

• Qualcomm Inc

Inventors

• Xu Hao
• Montojo Juan
• Luo Tao
• Gaal Peter

Classifications

• H04W52/146

  Uplink power control · CPC title

• H04W52/12

  Outer and inner loops · CPC title

• H04W52/325 Primary

  Power control of control or pilot channels · CPC title

• H04W52/04 Primary

  Transmission power control [TPC] · CPC title