Listen-before-talk and channel reservation for millimeter wave systems

Patent metadata

Field	Value
Publication number	US-2019090279-A1
Application number	US-201816133163-A
Country	US
Kind code	A1
Filing date	Sep 17, 2018
Priority date	Sep 19, 2017
Publication date	Mar 21, 2019
Grant date	—

Abstract

Methods, systems, and devices for wireless communications are described. A method may include receiving, from a base station, a pre-grant message indicating that a downlink transmission is available for transmission to a user equipment (UE) on a first radio frequency (RF) spectrum band, and performing a listen-before-talk (LBT) procedure. The UE may then transmit, based on the LBT procedure indicating a clear channel, a channel reservation signal on a second RF spectrum band, and transmit, to the base station, a response to the pre-grant message on the second RF spectrum band. Another method may include a base station transmitting a pre-grant message to the UE, and receiving a response to the pre-grant message on a second RF spectrum band. The base station may then transmit the downlink transmission to the UE using one or more of a set of transmit beams on a first RF spectrum band.

First claim

What is claimed is:

1 . A method for wireless communication at a base station, comprising:
transmitting, to a user equipment (UE), a pre-grant message indicating that a downlink transmission is available for transmission to the UE on a first radio frequency (RF) spectrum band; receiving, from the UE, a response to the pre-grant message on a second RF spectrum band; and transmitting, based at least in part on receiving the response to the pre-grant message, the downlink transmission to the UE using one or more of a set of transmit beams on the first RF spectrum band.

2 . The method of claim 1 , further comprising:
performing a listen-before-talk (LBT) procedure in the second RF spectrum band, wherein the pre-grant message is transmitted based at least in part on the LBT procedure indicating a clear channel.

3 . The method of claim 1 , wherein transmitting the pre-grant message to the UE comprises:
transmitting the pre-grant message to the UE in the first RF spectrum band or the second RF spectrum band.

4 . The method of claim 1 , further comprising:
receiving, from the UE on the second RF spectrum band, one or more acknowledgement (ACK) or non-acknowledgment (NACK) messages in response to transmitting the downlink transmission to the UE.

5 . The method of claim 1 , wherein the pre-grant message indicates a duration for a transmission opportunity (TxOP).

6 . The method of claim 1 , further comprising:
receiving, from a second UE, a channel reservation signal on the second RF spectrum band; and refraining from transmitting on the first RF spectrum band based at least in part on receiving the channel reservation signal.

7 . The method of claim 6 , wherein the channel reservation signal comprises a preamble indicating a duration; and the base station refrains from transmitting for the indicated duration.

8 . The method of claim 6 , wherein the channel reservation transmission is a physical uplink control channel (PUCCH) waveform.

9 . The method of claim 1 , wherein the first RF spectrum band comprises a RF spectrum band above 6 GHz; and the second RF spectrum band comprises a RF spectrum band below 6 GHz.

10 . The method of claim 1 , wherein:
the first RF spectrum band comprises an unlicensed or a shared access RF spectrum band; and the second RF spectrum band comprises an unlicensed, or a shared access, or a licensed RF spectrum band.

11 . The method of claim 10 , wherein:
the second RF spectrum band comprises the licensed RF spectrum band, wherein the licensed RF spectrum band comprises a frequency division duplexing (FDD) licensed or time division duplexing (TDD) licensed spectrum band.

12 . The method of claim 1 , wherein:
the pre-grant message is transmitted without performing a listen-before-talk (LBT) procedure to indicate a clear channel for the pre-grant message transmission.

13 . The method of claim 1 , wherein:
transmissions from the UE are received in a spectrum band other than the first RF spectrum band based at least in part on the base station lacking an uplink reception capability in the first RF spectrum band.

14 . A method for wireless communication at a user equipment (UE), comprising:
receiving, from a base station, a pre-grant message indicating that a downlink transmission is available for transmission to the UE on a first radio frequency (RF) spectrum band; performing a listen-before-talk (LBT) procedure based at least in part on receiving the pre-grant message; transmitting, based at least in part on the LBT procedure indicating a clear channel, a channel reservation signal on a second RF spectrum band; and transmitting, to the base station, a response to the pre-grant message on the second RF spectrum band.

15 . The method of claim 14 , wherein performing the LBT procedure comprises:
performing the LBT procedure in the first RF spectrum band based at least in part on receiving the pre-grant message.

16 . The method of claim 14 , further comprising:
receiving the downlink transmission from the base station on the first RF spectrum band, the downlink transmission transmitted by the base station using one or more of a set of transmit beams on the first RF spectrum band.

17 . The method of claim 16 , further comprising:
transmitting, to the base station on the second RF spectrum band, one or more acknowledgement (ACK) or non-acknowledgment (NACK) messages in response to receiving the downlink transmission at the UE.

18 . The method of claim 14 , wherein receiving the pre-grant message comprises receiving in the first RF spectrum or the second RF spectrum.

19 . The method of claim 14 , wherein performing the LBT procedure comprises:
performing the LBT procedure in the second RF spectrum band based at least in part on receiving the pre-grant message.

20 . The method of claim 19 , further comprising:
performing a second LBT procedure in the second RF spectrum band, wherein transmitting the channel reservation signal is based at least in part on the LBT procedure indicating the clear channel and the second LBT procedure indicating a second clear channel.

21 . The method of claim 14 , wherein the pre-grant message indicates a duration for a transmission opportunity (TxOP).

22 . The method of claim 21 , wherein the channel reservation signal comprises a preamble indicating the duration.

23 . The method of claim 14 , wherein the LBT procedure comprises a category 4 LBT, or a one-shot LBT, or a combination thereof.

24 . The method of claim 14 , further comprising:
frequency division duplexing an uplink carrier carrying the channel reservation signal.

25 . The method of claim 14 , further comprising:
time division duplexing an uplink carrier carrying the channel reservation signal.

26 . The method of claim 14 , wherein the channel reservation transmission is a physical uplink control channel (PUCCH) waveform.

27 . The method of claim 14 , wherein the first RF spectrum band comprises a RF spectrum band above 6 GHz; and the second RF spectrum band comprises a RF spectrum band below 6 GHz.

28 . The method of claim 27 , wherein:
the first RF spectrum band comprises an unlicensed or a shared access RF spectrum band; and the second RF spectrum band comprises an unlicensed, or a shared access, or a licensed RF spectrum band.

29 . The method of claim 28 , wherein:
the second RF spectrum band comprises the licensed RF spectrum band, wherein the licensed RF spectrum band comprises a frequency division duplexing (FDD) licensed or time division duplexing (TDD) licensed spectrum band.

30 . The method of claim 14 , wherein:
transmissions from the UE are transmitted in a spectrum band other than the first RF spectrum band based at least in part on the base station lacking an uplink transmission capability in the first RF spectrum band.

31 . 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: transmit, to a user equipment (UE), a pre-grant message indicating that a downlink transmission is available for transmission to the UE on a first radio frequency (RF) spectrum band; receive, from the UE, a response to

Assignees

• Qualcomm Inc

Inventors

• Sun Jing
• Zhang Xiaoxia

Classifications

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04W74/0816 Primary

  with collision avoidance · CPC title

• H04L5/0055

  Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861) · CPC title

• H04W28/26

  Resource reservation · CPC title

• H04L5/14

  Two-way operation using the same type of signal, i.e. duplex · CPC title