METHOD FOR TRANSMITTING D2D SIGNAL AND APPARATUS FOR SAME

• US 20160173239A1
• Filed: 08/06/2014
• Published: 06/16/2016
• Est. Priority Date: 08/06/2013
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: KIM, Hakseong, SEO, Hanbyul
• Granted Patent: US 9,838,163 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/1861 Physical mapping arrangements for ACK signaling see also H04L5/0053
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

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.

Claims

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 signal from a base station in response to the data.

2. The method of claim 1, if the HARQ response corresponds to the NACK (negative acknowledgement), further comprising the step of receiving a retransmission indicator from the second D2D UE at first timing,

wherein second timing at which the retransmission signal received from the base station in response to the data is determined based on the first timing.

3. The method of claim 1, wherein a CRC (cyclic redundancy check) of a PDCCH (physical downlink control channel) 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.

4. The method of claim 1, wherein if a plurality of data are continuously received from the first D2D UE, 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.

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

6. 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, the processor configured to transmit a HARQ response to the second D2D UE in response to the data, the processor, if the HARQ response corresponds to NACK (negative acknowledgement), configured to receive a retransmission signal from a base station in response to the data.

7. The first D2D UE of claim 6, wherein if the HARQ response corresponds to the NACK (negative acknowledgement), the processor is configured to receive a retransmission indicator from the second D2D UE at first timing and wherein second timing at which the retransmission signal received from the base station in response to the data is determined based on the first timing.

8. The first D2D UE of claim 6, wherein a CRC (cyclic redundancy check) of a PDCCH (physical downlink control channel) 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.

9. The first D2D UE of claim 6, wherein if a plurality of data are continuously received from the first D2D UE, 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.

10. The first D2D UE of claim 6, wherein if the HARQ response corresponds to ACK, transmission of the HARQ response signal is omitted at timing assigned to transmit the HARQ response.