Method for performing an ACK/NACK indication based on the uplink grants over multiple subframes in a wireless communication system and a device therefor

• US 10,609,728 B2
• Filed: 05/18/2016
• Issued: 03/31/2020
• Est. Priority Date: 05/22/2015
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Sunyoung, Yi, Seungjune
• Primary Examiner(s): Kassim, Khaled M
• Application Number:
  US15/567,588
• Publication Number:
  US 20180294940A1
• Time in Patent Office: 1,413 Days
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/1848 Time-out mechanisms
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04W 28/0278 using buffer status reports dynamic wireless traffic scheduling definition H04W72/12
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/1268 of uplink data flows
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states

Abstract

The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for performing an ACK/NACK indication based on the uplink grants over multiple subframes in a wireless communication system, the method comprising: starting a timer when an uplink grant is received from an eNB, wherein the uplink grant is valid while the timer is running; transmitting data using the uplink grant if the data is generated while the timer is running; monitoring an ACK indication or an or a NACK indication for the transmitted data on a subframe; checking whether the timer is running or not if the ACK indication for the transmitted data is not received on the subframe; and retransmitting the data using the uplink grant if the timer is running.

Claims

1. A method for a User Equipment (UE) operating in a wireless communication system, the method comprising:

triggering a first buffer status reporting (BSR) by generating virtual data, when the UE expects that there is data to be generated;

transmitting the triggered BSR;

receiving an uplink grant in response to the transmitted BSR;

starting a timer when the uplink grant is received from a Base Station (BS), wherein the uplink grant is valid while the timer is running;

when actual data is generated while the timer is running;

transmitting the actual data on the uplink grant;

monitoring an Acknowledgement (ACK) indication and a Negative-Acknowledgement (NACK) indication for the actual data on a subframe;

determining whether the timer is running or not when the ACK indication for the actual data is not received on the subframe or the NACK indication for the actual data is received on the subframe;

retransmitting the actual data on the uplink grant based on a determination that the timer is running; and

discarding the uplink grant and keeping the actual data based on a determination that the timer is not running; and

when the actual data is not generated while the timer is running;

discarding the uplink grant.

2. The method according to claim 1, wherein further comprising:

triggering a second BSR when the uplink grant is discarded.

3. The method according to claim 1, wherein a value of the timer is configured by the BS via Radio Resource Control (RRC) signaling, or is pre-configured, or is received with the uplink grant.

4. The method according to claim 3, wherein the value of the timer is equal to or larger than two subframes.

5. A User Equipment (UE) for operating in a wireless communication system, the UE comprising:

a Radio Frequency (RF) module; and

a processor operably coupled with the RF module and configured to;

trigger a first buffer status reporting (BSR) by generating virtual data, when the UE expects that there is data to be generated;

transmit the triggered BSR;

receive an uplink grant in response to the transmitted BSR;

start a timer when the uplink grant is received from a Base Station (BS), wherein the uplink grant is valid while the timer is running;

when actual data is generated while the timer is running;

transmit the actual data on the uplink grant;

monitor an Acknowledgement (ACK) indication and a Negative-Acknowledgement (NACK) indication for the transmitted data on a subframe;

determine whether the timer is running or not when the ACK indication for the actual data is not received on the subframe or the NACK indication for the actual data is received on the subframe;

retransmit the actual data on the uplink grant based on a determination that the timer is running; and

discard the uplink grant and keep the actual data based on a determination that the timer is not running; and

when the actual data is not generated while the timer is running;

discarding the uplink grant.

6. The UE according to claim 5, wherein the processor is further configured to:

trigger a second buffer status reporting (BSR) when the uplink grant is discarded.

7. The UE according to claim 5, wherein a value of the timer is configured by the BS via Radio Resource Control (RRC) signaling, or is pre-configured, or is received with the uplink grant.

8. The UE according to claim 7, wherein the value of the timer is equal to or larger than two subframes.