Techniques for transmission of sounding reference signal in shared radio frequency spectrum band

Patent metadata

Field	Value
Publication number	US-2017195890-A1
Application number	US-201615392290-A
Country	US
Kind code	A1
Filing date	Dec 28, 2016
Priority date	Dec 30, 2015
Publication date	Jul 6, 2017
Grant date	—

Abstract

Sounding reference signal (SRS) transmissions in a shared RF spectrum band, alone or in conjunction with a dedicated RF spectrum band, may be transmitted using two or more uplink component carriers (CCs). A UE may identify that the two or more CCs are in a same timing advance group (TAG), and transmit a SRS transmission and a physical uplink shared channel (PUSCH) or physical uplink control channel (PUCCH) transmission during a same uplink symbol. A UE may transmit a SRS based on a minimum configured power in the event that the UE is power limited during a SRS transmission symbol. A channel priority assigned to a CC carrying a SRS transmission in a shared RF spectrum band may be set to a higher channel priority than a channel priority for a similar transmission using a dedicated RF spectrum band.

First claim

What is claimed is:

1 . A method for wireless communication at a user equipment (UE), comprising:
establishing wireless communications using two or more uplink component carriers (CCs) in a wireless communications network, at least one of the two or more uplink CCs using a shared radio frequency (RF) spectrum band; identifying that each of the two or more uplink CCs are configured to be in a same timing advance group (TAG); identifying a sounding reference signal (SRS) to be transmitted in a first symbol using a first uplink CC of the two or more uplink CCs; determining that one or more of a physical uplink shared channel (PUSCH) transmission or a physical uplink control channel (PUCCH) transmission is to be transmitted in the first symbol using a second uplink CC of the two or more uplink CCs; and transmitting, in the first symbol, the SRS using the first uplink CC and one or more of the PUSCH or PUCCH using the second uplink CC.

2 . The method of claim 1 , wherein the transmitting further comprises:
determining that a transmission during the first symbol using the two or more uplink CCs is not power limited.

3 . The method of claim 1 , wherein the transmitting further comprises:
determining that the transmission during the first symbol using the two or more uplink CCs is power limited; and dropping the transmission of the SRS.

4 . The method of claim 1 , wherein the transmitting further comprises:
determining that the transmission during the first symbol using the two or more uplink CCs is power limited; and transmitting of the SRS based at least in part on a minimum power level configured for transmission of the first uplink CC.

5 . The method of claim 1 , wherein the first uplink CC is part of the shared RF spectrum band.

6 . The method of claim 1 , wherein the first uplink CC is not part of the shared RF spectrum band.

7 . The method of claim 1 , wherein the transmitting further comprises:
transmitting the SRS during a regular uplink subframe of a radio frame.

8 . The method of claim 1 , wherein the transmitting further comprises:
transmitting the SRS during a special subframe of a radio frame.

9 . The method of claim 8 , wherein the transmitting further comprises:
transmitting two or more SRS symbols during an uplink pilot time slot (UpPTS) of the special subframe.

10 . The method of claim 1 , wherein the transmitting further comprises:
transmitting the SRS using the first uplink CC over the shared RF spectrum band using a channel priority that is different than a channel priority for transmitting the SRS using a CC over a dedicated RF spectrum band.

11 . The method of claim 1 , wherein the transmitting further comprises:
formatting the SRS to span a frequency bandwidth of the first symbol.

12 . The method of claim 11 , wherein the formatting is based at least in part on a power spectral density limit of the frequency bandwidth.

13 . The method of claim 1 , wherein the two or more uplink CCs comprise a first set of uplink CCs that are allocated for uplink transmissions during a transmission time interval (TTI), and wherein the transmitting further comprises:
transmitting one or more of the PUCCH transmission or PUSCH transmission using the first set of uplink CCs; and transmitting the SRS using a different uplink CC that is outside of the first set of uplink CCs.

14 . The method of claim 13 , wherein the different uplink CC is a CC associated with a second set of downlink CCs, and wherein the first set of uplink CCs comprise fewer CCs than the second set of downlink CCs.

15 . The method of claim 1 , wherein the first uplink CC and the second uplink CC are different CCs.

16 . A method for wireless communication at a base station, comprising:
configuring wireless communications at a user equipment (UE) using two or more uplink component carriers (CCs) in a wireless communications network, at least one of the two or more uplink CCs using a shared radio frequency (RF) spectrum band; configuring each of the two or more uplink CCs to be in a same timing advance group (TAG); and configuring a sounding reference signal (SRS) to be transmitted in a first symbol using a first uplink CC of the two or more uplink CCs concurrently with one or more of a physical uplink shared channel (PUSCH) transmission or a physical uplink control channel (PUCCH) transmission to be transmitted during the first symbol using a second uplink CC of the two or more uplink CCs.

17 . The method of claim 16 , further comprising:
configuring the SRS to be transmitted based at least in part on a minimum transmission power level that is to be used when a transmission during the first symbol using the two or more uplink CCs is power limited.

18 . The method of claim 16 , wherein the first uplink CC is part of the shared RF spectrum band.

19 . The method of claim 16 , wherein the first uplink CC is not part of the shared RF spectrum band.

20 . The method of claim 16 wherein the configuring the SRS to be transmitted further comprises:
configuring the SRS to be transmitted during a regular uplink subframe of a radio frame.

21 . The method of claim 16 , wherein the configuring the SRS to be transmitted further comprises:
configuring the SRS to be transmitted during a special subframe of a radio frame.

22 . The method of claim 21 , wherein the configuring further comprises:
configuring one or more SRS symbols to be transmitted during an uplink pilot time slot (UpPTS) of the special subframe.

23 . The method of claim 16 , wherein the configuring the SRS to be transmitted further comprises:
configuring the first uplink CC to be transmitted over the shared RF spectrum band using a channel priority that is different than a channel priority for transmitting the second uplink CC to be transmitted over a dedicated RF spectrum band.

24 . The method of claim 16 , wherein the configuring the SRS to be transmitted further comprises:
configuring the SRS to span a frequency bandwidth of the first symbol.

25 . The method of claim 24 , wherein the frequency bandwidth for the SRS is configured based at least in part on a power spectral density limit of the frequency bandwidth.

26 . The method of claim 16 , further comprising:
allocating a first set of uplink CCs that includes the two or more uplink CCs for uplink transmissions during a transmission time interval (TTI); transmitting downlink transmissions using a second set of downlink CCs that includes different CCs than the first set of uplink CCs; and wherein the configuring the SRS to be transmitted further comprises configuring the SRS to be transmitted using a CC of the second set of downlink CCs that is outside of the first set of uplink CCs.

27 . The method of claim 16 , wherein the first uplink CC and the second uplink CC are different CCs.

28 . An apparatus for wireless communication, 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:
establish wireless communications using two or more uplink component carriers (CCs) in a wireless communications network, at least one of the two or more uplink CCs using a shared radio frequency (RF) spectrum band;
identify that each of the two or more uplink CCs are co

Assignees

• Qualcomm Inc

Inventors

• Chen Wanshi
• Gaal Peter

Classifications

• H04L5/001 Primary

  the frequencies being arranged in component carriers · CPC title

• H04W72/21

  in the uplink direction of a wireless link, i.e. towards the network · CPC title

• H04W52/30

  using constraints in the total amount of available transmission power · CPC title

• H04L5/0048 Primary

  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

• H04W72/0453

  Resources in frequency domain, e.g. a carrier in FDMA · CPC title