Uplink scheduling for license assisted access

Patent metadata

Field	Value
Publication number	US-2017366308-A1
Application number	US-201515537024-A
Country	US
Kind code	A1
Filing date	Dec 10, 2015
Priority date	Jan 30, 2015
Publication date	Dec 21, 2017
Grant date	—

Abstract

Systems, apparatus, user equipment (UE), evolved node B (eNB), computer readable media, and methods are described for uplink grants and hybrid automatic repeat requests (HARQ) in communications systems. Some embodiments operate to determine that an unlicensed first channel is idle based on a sensing of the first channel for a first period of time. Such an embodiment may then generate a reservation signal on the first channel and an uplink grant for a first user equipment (UE). After the uplink grant is communicated, the embodiment senses the first channel to detect a physical uplink shared channel (PUSCH) transmission associated with the uplink grant. A HARQ acknowledgment or negative acknowledgement may be sent in various embodiments following the sensing.

First claim

1 . A computer readable medium comprising instructions that, when executed by one or more processors, configure an evolved node B (eNB) for license assisted access (LAA) communications, the instructions to configure the eNB to:
determine, by the eNB, that a first channel is idle based on a sensing of the first channel for a first period of time; initiate, based on the determination that the first channel is idle, a reservation signal on the first channel for a second period of time following the first period of time; initiate transmission of an uplink grant to a first user equipment (UE), the uplink grant associated with the first channel and a third period of time following the second period of time; and sense, by the eNB, the first channel during the third period of tune to detect a physical uplink shared channel (PUSCH) transmission associated with the uplink grant.

2 . The computer readable medium of claim 1 wherein the second period of time is separated from the third period of time by a UE sensing period such that the first UE senses the first channel during the sensing period following transmission of the reservation signal to determine that the first channel is idle during the UE sensing period.

3 . The computer readable medium of claim 1 wherein the third period of time immediately follows the second period of time; and
wherein the UE is configured to communicate the PUSCH transmission on the first channel during the third period of time without performing a listen-before-talk (LBT) operation.

4 . The computer readable medium of claim 3 wherein the uplink grant is communicated from the eNB to the first UE on a second channel different from the first channel as part of a physical downlink control channel (PDCCH) transmission.

5 . The computer readable medium of claim 4 wherein the reservation signal comprises one or more of a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), and a demodulation reference signal (DRS).

6 . The computer readable medium of claim 5 where the reservation signal comprises a primary synchronization signal (PSS) and a secondary synchronization signal (SSS).

7 . The computer readable medium of claim 6 wherein the instructions further configure the eNB to:
receive a plurality of scheduling requests from a plurality of UEs, the plurality of UEs comprising the first UE;
wherein initiating transmission of an uplink grant to the first UE comprises initiating transmission of the uplink grant to each UE of the plurality of UEs.

8 . The computer readable medium of claim 7 wherein the instructions further configure the eNB to assign a first license assisted access radio network temporary identifier to each UE of the plurality of UEs, wherein the license assisted access radio network temporary identifier is separate from a cell radio network temporary identifier (C-RNTI) for each UE of the plurality of UEs;
wherein the transmission of the uplink grant is communicated to each UE of the plurality of UEs using the first license assisted access radio network temporary identifier such that the first plurality of UEs receives the downlink grant using a same identifier.

9 . The computer readable medium of claim 8 wherein each UE of the plurality of UE performs a listen before talk (LBT) operation after receiving the uplink grant;
wherein the first UE completes a successful carrier sensing operation and reserves the first channel with a second reservation signal prior to each other UE of the plurality of UEs.

10 . The computer readable medium of claim 9 wherein the second reservation signal comprises a first C-RNTI for the first UE.

11 . The computer readable medium of claim 10 wherein the instructions further configure the eNB to:
successfully decode the PUSCH transmission associated with the uplink grant; and
transmit a synchronous hybrid automatic repeat request associated with the PUSCH transmission to the first UE.

12 . The computer readable medium of claim 10 wherein the instructions further configure the eNB to:
determine that the eNB has failed to identify the PUSCH transmission on the first channel during the third period of time; and
transmit an asynchronous hybrid automatic repeat request from the eNB to the first UE in response to the failure to identify the PUSCH transmission.

13 . The computer readable medium of claim 12 wherein the uplink grant comprises a transmission grant associated with the third time period and a retransmission grant associated with a fourth time period following the second time period.

14 . The computer readable medium of claim 13 wherein a number of physical resource blocks for the uplink grant are adjusted dynamically by the eNB between the third time period and the fourth time period.

15 . The computer readable medium of claim 13 wherein the modulation and coding scheme associated with the uplink grant is set dynamically by the eNB based on the sensing of the first channel for a first period of time and the failure to identify the PUSCH transmission.

16 . The computer readable medium of claim 15 wherein the uplink grant wherein the uplink grant is communicated to the UE from the eNB via a physical downlink control channel (PDCCH) transmitted on a first licensed channel separate from the first channel.

17 . An apparatus of an evolved node B (eNB) comprising control circuitry configured to:
determine that a first channel is idle based on a sensing of the first channel for a first period of time; initiate, based on the determination that the first channel is idle, a reservation signal on the first channel for a second period of time following the first period of time; initiate transmission of an uplink grant to a first user equipment (UE), the uplink grant associated with the first channel and a third period of time following the second period of time; and initiate sensing of the first channel during the third period of time to detect a physical uplink shared channel (PUSCH) transmission associated with the uplink grant; and generate a hybrid automatic repeat request for transmission to the first UE in response to the sensing of the first channel.

18 . The apparatus of claim 1 further comprising:
receive circuitry coupled to the control circuitry and configured to sense the first channel during the first period of time and the second period of time and to receive the PUSCH transmission; and
transmit circuitry coupled to the control circuitry and configured to transmit the reservation signal to the first UE on the first channel.

19 . The apparatus of claim 17 wherein the receive circuitry and the transmit circuitry are coupled to a first antenna;
wherein the first antenna is configured for communications on the first channel comprising an unlicensed channel and wherein the first antenna is further configured for communications on a second channel comprising a licensed channel.

20 . A computer readable medium comprising instructions that, when executed by one or more processors, configure a user equipment (UE) for license assisted access communication with an evolved node B (eNB), the instructions to configure the UE to:
receive, from the eNB, an uplink grant associated with a first unlicensed channel and a first period of time; determine that the first unlicensed channel is available for a physical uplink shared channel (PUSCH) transmission during the first period of time; transmit the PUSCH transmission to the eNB during the first period of time; and receive a

Assignees

• Intel Ip Corp

Inventors

• Choi Gi Wan
• Kwon Hwan-Joon
• Bhorkar Abhijeet

Classifications

• H04W72/23

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

• H04W72/21 Primary

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

• H04W74/0816

  with collision avoidance · CPC title

• H04L5/0055 Primary

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

• H04J11/00

  Orthogonal multiplex systems, {e.g. using WALSH codes}(H04J13/00 takes precedence) · CPC title