Method for transmitting D2D signal and apparatus for same

Patent metadata

Field	Value
Publication number	US-9838163-B2
Application number	US-201414908464-A
Country	US
Kind code	B2
Filing date	Aug 6, 2014
Priority date	Aug 6, 2013
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

The present invention relates to a wireless communication system. More specifically, the present invention relates to a method for performing an HARQ process by a first D2D terminal in a wireless communication system, and an apparatus for the same, the method comprising the steps of: receiving data from a second D2D terminal; transmitting an HARQ response for the data to the second D2D terminal; and when the HARQ response is NACK, receiving a retransmission signal for the data from a base station.

First claim

What is claimed is:

1. A method of performing a HARQ (hybrid automatic repeat request) procedure, which is performed by a first D2D (device-to-device) UE in a wireless communication system, comprising the steps of:
receiving data from a second D2D UE;
transmitting a HARQ response to the second D2D UE in response to the data; and
if the HARQ response corresponds to NACK (negative acknowledgement),
receiving a retransmission indicator from the second D2D UE at a first timing, and
receiving a retransmission signal from a base station in response to the data at a second timing,
wherein the second timing is determined based on the first timing.

2. The method of claim 1 , further comprising:
receiving a PDCCH (physical downlink control channel) scheduling the data,
wherein a CRC (cyclic redundancy check) of the PDCCH scheduling the data is masked with a group-RNTI (radio network temporary identifier), and
wherein the group-RNTI is determined based on a group ID (identifier) of a group to which the first D2D UE and the second D2D UE belong thereto.

3. The method of claim 1 ,
wherein, if the data includes a plurality of continuously received data, the HARQ response is transmitted in a subframe satisfying (10*SFN+SF) mod N=0 only,
wherein the SFN corresponds to a radio frame index,
wherein the SF corresponds to a subframe index in a radio frame,
wherein the mod indicates a modulo calculation, and
wherein the N corresponds to an integer equal to or greater than 2.

4. The method of claim 1 , wherein if the HARQ response corresponds to ACK, transmission of the HARQ response signal is omitted at a timing assigned to transmit the HARQ response.

5. A first D2D (device-to-device) UE configured to perform a HARQ (hybrid automatic repeat request) procedure in a wireless communication system, comprising:
an RF (radio frequency) unit; and
a processor, the processor configured to
receive data from a second D2D UE, transmit a HARQ response to the second D2D UE in response to the data, and

if the HARQ response corresponds to NACK (negative acknowledgement),
receive a retransmission indicator from the second D2D UE at a first timing, and
receive a retransmission signal from a base station in response to the data at a second timing,
wherein the second timing is determined based on the first timing.

6. The first D2D UE of claim 5 ,
wherein the processor is further configured to receive a PDCCH (physical downlink control channel) scheduling the data, and
wherein a CRC (cyclic redundancy check) of the PDCCH scheduling the data is masked with a group-RNTI (radio network temporary identifier), and
wherein the group-RNTI is determined based on a group ID (identifier) of a group to which the first D2D UE and the second D2D UE belong thereto.

7. The first D2D UE of claim 5 ,
wherein, if the data includes a plurality of continuously received data, the HARQ response is transmitted in a subframe satisfying (10*SFN+SF) mod N=0 only,
wherein the SFN corresponds to a radio frame index,
wherein the SF corresponds to a subframe index in a radio frame,
wherein the mod indicates a modulo calculation, and
wherein the N corresponds to an integer equal to or greater than 2.

8. The first D2D UE of claim 5 , wherein if the HARQ response corresponds to ACK, transmission of the HARQ response signal is omitted at a timing assigned to transmit the HARQ response.

Assignees

• Lg Electronics Inc

Inventors

• Kim Hakseong
• Seo Hanbyul

Classifications

• H04W72/23

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

• H04L1/1861 Primary

  Physical mapping arrangements (for ACK signaling see also H04L5/0053) · CPC title

• H04L1/1812

  Hybrid protocols; Hybrid automatic repeat request [HARQ] · CPC title

• H04W72/042

  Electricity · mapped topic

• H04L1/1854

  Scheduling and prioritising arrangements · CPC title