Reference signal transmission based on received signal quality

Patent metadata

Field	Value
Publication number	US-10405299-B2
Application number	US-201715471658-A
Country	US
Kind code	B2
Filing date	Mar 28, 2017
Priority date	Sep 14, 2016
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

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.

First claim

What is claimed is:

1. A method for wireless communication, the method comprising:
determining, at a user equipment (UE), that a reference signal (RS) transmission has been triggered for a time unit;
receiving, from a base station, an antenna selection authorization indication associated with a first set of time units;
selecting a subset of antennas from a set of available antennas, wherein the selecting comprises autonomously selecting the subset of antennas by the UE if the time unit is within the first set of time units based at least in part on a signal property associated with each antenna of the subset of antennas and the antenna selection authorization indication, and wherein the selecting comprises selecting predetermined antennas if the time unit is within a second set of time units; and
transmitting the RS transmission using the selected subset of antennas during the time unit.

2. The method of claim 1 , further comprising:
determining that the RS transmission has been triggered comprises receiving a trigger message from the base station, or identifying a 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
wherein the selecting is 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 , wherein the antenna selection authorization indication is received in a system information block (SIB), or a radio resource control (RRC) message, or a trigger message, or combinations thereof.

12. The method of claim 11 , wherein
the first and the second sets of time units each comprise 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 each 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 the 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, the apparatus comprising:
means for determining, at a user equipment (UE), that a reference signal (RS) transmission has been triggered for a time unit;
means for receiving, from a base station, an antenna selection authorization indication associated with a first set of time units;
means for selecting a subset of antennas from a set of available antennas, wherein the means for selecting comprises means for autonomously selecting the subset of antennas by the UE if the time unit is within the first set of time units based at least in part on a signal property associated with each antenna of the subset of antennas and the antenna selection authorization indication, and wherein the means for selecting comprises means for selecting predetermined antennas if the time unit is within a second set of time units; and
means for transmitting the RS transmission using the selected subset of antennas during the time unit.

18. An apparatus for wireless communication, in a system, the apparatus 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 for a time unit;
receive, from a base station, an antenna selection authorization indication associated with a first set of time units;
select a subset of antennas from a set of available antennas, wherein the instructions to select comprise instructions to autonomously select the subset of antennas by the UE if the time unit is within the first set of time units based at least in part on a signal property associated with each antenna of the subset of antennas and the antenna selection authorization indication, and wherein the instructions to select comprise instructions to select predetermined antennas if the time unit is within a second set of time units; and
transmit the RS transmission using the selected subset of antennas during the time unit.

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 the base station, or identifying a 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
wherein the selection of the

Assignees

• Qualcomm Inc

Inventors

• Rico Alvarino Alberto
• Chen Wanshi
• Xu Hao
• Gaal Peter

Classifications

• H04W72/542

  using measured or perceived quality · CPC title

• H04B7/0874

  using subgroups of receive antennas · CPC title

• H04B7/0691

  using subgroups of transmit antennas · CPC title

• H04B7/0608 Primary

  Antenna selection according to transmission parameters · CPC title

• H04L5/0048

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title