REFERENCE SIGNAL TRANSMISSION BASED ON RECEIVED SIGNAL QUALITY

• US 20180077683A1
• Filed: 03/28/2017
• Published: 03/15/2018
• Est. Priority Date: 09/14/2016
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Rico Alvarino, Alberto, Chen, Wanshi, Xu, Hao, Gaal, Peter
• Granted Patent: US 10,405,299 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 7/0404 the mobile station comprising multiple antennas, e.g. to provide uplink diversity
• CPC Class Codes: H04B 7/0608 Antenna selection according to transmission parameters
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04B 7/0874 using subgroups of receive antennas
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

Methods, systems, and devices for wireless communication are described. A user equipment (UE) may determine that a reference signal (RS) transmission has been triggered. The UE may select a subset of antennas from a set of available antennas based on a signal property associated with each antenna of the subset of antennas. The UE may transmit the RS using the selected subset of antennas.

Claims

1. A method for wireless communication, comprising:

determining, at a user equipment (UE), that a reference signal (RS) transmission has been triggered;

selecting a subset of antennas from a set of available antennas based at least in part on a signal property associated with each antenna of the subset of antennas; and

transmitting the RS using the selected subset of antennas.

2. The method of claim 1, further comprising:

determining that the RS transmission has been triggered comprises receiving a trigger message from a base station, or identifying the RS transmission trigger according to a configured periodic schedule, or combinations thereof.

3. The method of claim 1, further comprising:

identifying a received signal quality associated with each antenna, wherein the signal property is based at least in part on the received signal quality; and

selecting the subset of antennas based at least in part on the received signal quality.

4. The method of claim 3, wherein

the selecting is based on the received signal quality satisfying a threshold level.

5. The method of claim 3, further comprising:

selecting a single antenna as the subset of antennas when the received signal quality for each antenna of the set of available antennas fails to satisfy a threshold level.

6. The method of claim 1, further comprising:

identifying an available transmission power associated with the UE, wherein the signal property is based at least in part on the available transmission power; and

selecting the subset of antennas based at least in part on the available transmission power.

7. The method of claim 6, further comprising:

identifying a power scaling factor for the RS transmission using the subset of antennas.

8. The method of claim 1, further comprising:

identifying a bandwidth factor associated with the RS transmission, wherein the signal property is based at least in part on the bandwidth factor; and

selecting the subset of antennas based at least in part on the bandwidth factor.

9. The method of claim 1, further comprising:

identifying a correlation factor associated with each antenna, wherein the signal property is based at least in part on the correlation factor; and

selecting the subset of antennas based at least in part on the correlation factor failing to satisfy a threshold level.

10. The method of claim 1, further comprising:

identifying a Doppler property associated with each antenna, wherein the signal property is based at least in part on the Doppler property, further wherein the Doppler property comprises a Doppler spread, or a Doppler shift, or combinations thereof; and

selecting the subset of antennas based at least in part on the Doppler property satisfying a threshold level.

11. The method of claim 1, further comprising:

receiving an antenna selection authorization indication from a base station, wherein the indication is received in a system information block (SIB), or a radio resource control (RRC) message, or the RS trigger message, or combinations thereof.

12. The method of claim 11, wherein

the indication is associated with a predefined set of time units;

and

the predefined set of time units comprises a set of subframes, or a set of radio frames, or a set of slots, or a set of symbols, or combinations thereof.

13. The method of claim 1, further comprising:

selecting a transmission characteristic for the RS transmission from each antenna of the subset of antennas, wherein the selected transmission characteristic conveys an indication that identifies the antenna.

14. The method of claim 13, wherein

a first transmission characteristic is associated with a first antenna having a first received signal quality and a second transmission characteristic is associated with a second antenna having a second received signal quality, wherein the first received signal quality is higher than the second received signal quality.

15. The method of claim 14, further comprising:

transmitting a message to a base station to convey an indication of the first antenna having the first received signal quality and the second antenna having the second received signal quality.

16. The method of claim 1, further comprising:

determining that the RS transmission is a multi-carrier RS transmission; and

selecting the subset of antennas based at least in part on the multi-carrier RS transmission.

17. An apparatus for wireless communication, comprising:

means for determining, at a user equipment (UE), that a reference signal (RS) transmission has been triggered;

means for selecting a subset of antennas from a set of available antennas based at least in part on a signal property associated with each antenna of the subset of antennas; and

means for transmitting the RS using the selected subset of antennas.

18. An apparatus for wireless communication, in a system comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to;

determine, at a user equipment (UE), that a reference signal (RS) transmission has been triggered;

select a subset of antennas from a set of available antennas based at least in part on a signal property associated with each antenna of the subset of antennas; and

transmit the RS using the selected subset of antennas.

19. The apparatus of claim 18, wherein the instructions are further executable by the processor to cause the apparatus to:

determine that the RS transmission has been triggered comprises receiving a trigger message from a base station, or identifying the RS transmission trigger according to a configured periodic schedule, or combinations thereof.

20. The apparatus of claim 18, wherein the instructions are further executable by the processor to cause the apparatus to:

identify a received signal quality associated with each antenna, wherein the signal property is based at least in part on the received signal quality; and

select the subset of antennas based at least in part on the received signal quality.

21. The apparatus of claim 20, wherein

the selecting is based on the received signal quality satisfying a threshold level.

22. The apparatus of claim 20, wherein the instructions are further executable by the processor to cause the apparatus to:

select a single antenna as the subset of antennas when the received signal quality for each antenna of the set of available antennas fails to satisfy a threshold level.

23. The apparatus of claim 18, wherein the instructions are further executable by the processor to cause the apparatus to:

identify an available transmission power associated with the UE, wherein the signal property is based at least in part on the available transmission power; and

select the subset of antennas based at least in part on the available transmission power.

24. The apparatus of claim 18, wherein the instructions are further executable by the processor to cause the apparatus to:

identify a bandwidth factor associated with the RS transmission, wherein the signal property is based at least in part on the bandwidth factor; and

select the subset of antennas based at least in part on the bandwidth factor.

25. The apparatus of claim 18, wherein the instructions are further executable by the processor to cause the apparatus to:

identify a correlation factor associated with each antenna, wherein the signal property is based at least in part on the correlation factor; and

select the subset of antennas based at least in part on the correlation factor failing to satisfy a threshold level.

26. The apparatus of claim 18, wherein the instructions are further executable by the processor to cause the apparatus to:

identify a Doppler property associated with each antenna, wherein the signal property is based at least in part on the Doppler property, further wherein the Doppler property comprises a Doppler spread, or a Doppler shift, or combinations thereof; and

select the subset of antennas based at least in part on the Doppler property satisfying a threshold level.

27. The apparatus of claim 18, wherein the instructions are further executable by the processor to cause the apparatus to:

receive an antenna selection authorization indication from a base station, wherein the indication is received in a system information block (SIB), or a radio resource control (RRC) message, or the RS trigger message, or combinations thereof.

28. The apparatus of claim 18, wherein the instructions are further executable by the processor to cause the apparatus to:

select a transmission characteristic for the RS transmission from each antenna of the subset of antennas, wherein the selected transmission characteristic conveys an indication that identifies the antenna.

29. The apparatus of claim 28, wherein

a first transmission characteristic is associated with a first antenna having a first received signal quality and a second transmission characteristic is associated with a second antenna having a second received signal quality, wherein the first received signal quality is higher than the second received signal quality.

30. A non-transitory computer readable medium storing code for wireless communication, the code comprising instructions executable by a processor to:

determine, at a user equipment (UE), that a reference signal (RS) transmission has been triggered;

select a subset of antennas from a set of available antennas based at least in part on a signal property associated with each antenna of the subset of antennas; and

transmit the RS using the selected subset of antennas.