Antenna Switching in a Closed Loop Transmit Diversity System

• US 20120027112A1
• Filed: 02/02/2011
• Published: 02/02/2012
• Est. Priority Date: 02/05/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Jiang, Yibo, Sambhwani, Sharad Deepak, Hou, Jilei, Hunzinger, Jason Frank, Sun, Haitong
• Granted Patent: US 8,811,513 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 7/0404 the mobile station comprising multiple antennas, e.g. to provide uplink diversity
• CPC Class Codes: H04B 7/061 using feedback from receiving side

Abstract

A method for closed loop transmit diversity is disclosed. Data from user equipment (UE) that was transmitted using multiple transmit antennas is received. A new transmit antenna is selected for the UE. A new cycle period for the UE is determined. A new transmit antenna index and a testing indication based on the new cycle period are sent to the UE.

Claims

1. A method for closed loop transmit diversity, the method comprising:

receiving data from user equipment (UE) that was transmitted using multiple transmit antennas;

selecting a new transmit antenna for the UE;

determining a new cycle period for the UE; and

sending a new transmit antenna index and a testing indication based on the new cycle period to the UE.

2. The method of claim 1, wherein the selecting comprises comparing channel strength metrics of multiple transmit antennas to determine a stronger transmit antenna.

3. The method of claim 2, wherein the selecting further comprises determining the channel strength metrics by removing an effect of power control commands sent to the user equipment (UE).

4. The method of claim 2, wherein the selecting further comprises averaging the channel strength metrics over multiple slots within a frame or over multiple frames.

5. The method of claim 1, further comprising maintaining the new cycle period at a Node B, wherein the new cycle period comprises a testing period during which the user equipment (UE) transmits using a non-selected antenna and an extended use period during which the UE transmits using the selected antenna.

6. The method of claim 1, wherein the sending comprises using a Fractional Dedicated Physical Channel (F-DPCH).

7. The method of claim 1, wherein the testing indication indicates whether the user equipment (UE) should transmit a next frame using only the selected antenna or the selected antenna and a non-selected antenna.

8. The method of claim 1, wherein the new transmit antenna and the new cycle period are determined at an end of a current testing period.

9. The method of claim 1, further comprising encoding the new transmit antenna index using direct encoding or differential encoding.

10. A Node B for antenna switching in a closed loop transmit diversity system, comprising:

a processor;

memory in electronic communication with the processor;

instructions stored in the memory, the instructions being executable by the processor to;

receive data from user equipment (UE) that was transmitted using multiple transmit antennas;

select a new transmit antenna for the UE;

determine a new cycle period for the UE; and

send a new transmit antenna index and a testing indication based on the new cycle period to the UE.

11. The Node B of claim 10, wherein the instructions executable to select comprise instructions executable to compare channel strength metrics of multiple transmit antennas to determine a stronger transmit antenna.

12. The Node B of claim 11, wherein the instructions executable to select further comprise instructions executable to determine the channel strength metrics by removing an effect of power control commands sent to the user equipment (UE).

13. The Node B of claim 11, wherein the instructions executable to select further comprise instructions executable to average the channel strength metrics over multiple slots within a frame or over multiple frames.

14. The Node B of claim 10, further comprising instructions executable to maintain the new cycle period at a Node B, wherein the new cycle period comprises a testing period during which the user equipment (UE) transmits using a non-selected antenna and an extended use period during which the UE transmits using the selected antenna.

15. The Node B of claim 10, wherein the instructions executable to send comprise instructions executable to use a Fractional Dedicated Physical Channel (F-DPCH).

16. The Node B of claim 10, wherein the testing indication indicates whether the user equipment (UE) should transmit a next frame using only the selected antenna or the selected antenna and a non-selected antenna.

17. The Node B of claim 10, wherein the new transmit antenna and the new cycle period are determined at an end of a current testing period.

18. The Node B of claim 10, further comprising instructions executable to encode the new transmit antenna index using direct encoding or differential encoding.

19. A Node B for antenna switching in a closed loop transmit diversity system, comprising:

means for receiving data from user equipment (UE) that was transmitted using multiple transmit antennas;

means for selecting a new transmit antenna for the UE;

means for determining a new cycle period for the UE; and

means for sending a new transmit antenna index and a testing indication based on the new cycle period to the UE.

20. The Node B of claim 19, wherein the means for selecting comprise means for comparing channel strength metrics of multiple transmit antennas to determine a stronger transmit antenna.

21. The Node B of claim 20, wherein the means for selecting further comprise means for determining the channel strength metrics by removing an effect of power control commands sent to the user equipment (UE).

22. The Node B of claim 20, wherein the means for selecting further comprise means for averaging the channel strength metrics over multiple slots within a frame or over multiple frames.

23. A computer-program product for antenna switching in a closed loop transmit diversity system, the computer-program product comprising a non-transitory computer-readable medium having instructions thereon, the instructions comprising:

code for causing a Node B to receive data from user equipment (UE) that was transmitted using multiple transmit antennas;

code for causing the Node B to select a new transmit antenna for the UE;

code for causing the Node B to determine a new cycle period for the UE; and

code for causing the Node B to send a new transmit antenna index and a testing indication based on the new cycle period to the UE.

24. The computer-program product of claim 23, wherein the code for causing the Node B to select comprises code for causing the Node B to compare channel strength metrics of multiple transmit antennas to determine a stronger transmit antenna.

25. The computer-program product of claim 24, wherein the code for causing the Node B to select further comprises code for causing the Node B to determine the channel strength metrics by removing an effect of power control commands sent to the user equipment (UE).

26. The computer-program product of claim 25, wherein the code for causing the Node B to select further comprises code for causing the Node B to average the channel strength metrics over multiple slots within a frame or over multiple frames.

27. A method for switching antennas in a closed loop transmit diversity system, comprising:

transmitting data on the uplink using multiple transmit antennas;

receiving feedback data that comprises a selected transmit antenna index and an indication about whether a next frame is a test frame; and

transmitting the next frame on the uplink using one or more antennas indicated by the feedback data.

28. The method of claim 27, wherein the transmitting the next frame comprises:

transmitting, if the next frame is a test frame, the next frame using a selected transmit antenna and a non-selected transmit antenna; and

transmitting, if the next frame is not a test frame, the next frame using only the selected transmit antenna.

29. A wireless communication device for antenna switching in a closed loop transmit diversity system, comprising:

a processor;

memory in electronic communication with the processor;

instructions stored in the memory, the instructions being executable by the processor to;

transmit data on the uplink using multiple transmit antennas;

receive feedback data that comprises a selected transmit antenna index and an indication about whether a next frame is a test frame; and

transmit the next frame on the uplink using one or more antennas indicated by the feedback data.

30. The wireless communication device of claim 29, wherein the instructions executable to transmit the next frame comprises instructions executable to:

transmit, if the next frame is a test frame, the next frame using a selected transmit antenna and a non-selected transmit antenna; and

transmit, if the next frame is not a test frame, the next frame using only the selected transmit antenna.

31. A wireless communication device for switching antennas in a closed loop transmit diversity system, comprising:

means for transmitting data on the uplink using multiple transmit antennas;

means for receiving feedback data that comprises a selected transmit antenna index and an indication about whether a next frame is a test frame; and

means for transmitting the next frame on the uplink using one or more antennas indicated by the feedback data.

32. The wireless communication device of claim 31, wherein the transmitting the next frame comprises:

means for transmitting, if the next frame is a test frame, the next frame using a selected transmit antenna and a non-selected transmit antenna; and

means for transmitting, if the next frame is not a test frame, the next frame using only the selected transmit antenna.

33. A computer-program product for antenna switching in a closed loop transmit diversity system, the computer-program product comprising a non-transitory computer-readable medium having instructions thereon, the instructions comprising:

code for causing a wireless communication device to transmit data on the uplink using multiple transmit antennas;

code for causing the wireless communication device to receive feedback data that comprises the selected transmit antenna index and an indication about whether a next frame is a test frame; and

code for causing the wireless communication device to transmit the next frame on the uplink using one or more antennas indicated by the feedback data.

34. The computer-program product of claim 33, wherein the code for causing the wireless communication device to transmit the next frame comprises:

code for causing the wireless communication device to transmit, if the next frame is a test frame, the next frame using a selected transmit antenna and a non-selected transmit antenna; and

code for causing the wireless communication device to transmit, if the next frame is not a test frame, the next frame using only the selected transmit antenna.