Synchronization signal transmission method for D2D communication in wireless communication system, and device therefor

• US 10,536,234 B2
• Filed: 08/13/2015
• Issued: 01/14/2020
• Est. Priority Date: 08/13/2014
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Seungmin, Seo, Hanbyul
• Primary Examiner(s): Sam, Phirin
• Assistant Examiner(s): Ghafoerkhan, Faiyazkhan
• Application Number:
  US15/502,885
• Publication Number:
  US 20170237515A1
• Time in Patent Office: 1,615 Days
• Field of Search: None
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04J 11/0073 Acquisition of primary synchronisation channel, e.g. detection of cell-ID within cell-ID group
• CPC Class Codes: H04J 11/0086 Search parameters, e.g. search strategy, accumulation length, range of search, thresholds code acquisition in DSSS H04B1/7075
• CPC Class Codes: H04J 2211/006 Single carrier frequency division multiple access [SC FDMA]
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 76/14 Direct-mode setup

Abstract

The present invention relates to a method and a device for transmitting a device-to-device (D2D) synchronization signal of a first terminal in a wireless communication system. More specifically, the method comprises the steps of: setting at least one candidate value for a D2D synchronization signal period; and determining a D2D synchronization signal period for transmitting/receiving a D2D signal to/from a second terminal from among the at least one candidate value.

Claims

1. A method for transmitting a device-to-device (D2D) synchronization signal (SS) by a first user equipment (UE) in a wireless communication system, the method comprising:

receiving information related to a plurality of D2DSS candidate periods, wherein each of the D2DSS candidate periods is different from each other;

determining whether to perform a D2D communication with a second UE,

wherein the first and the second UEs are out-of-coverage UEs;

based on the determination to perform the D2D communication with the second UE;

receiving a first D2DSS from an in-coverage UE during a shortest period among the D2DSS candidate periods; and

transmitting a second D2DSS during the shortest period,

wherein the first D2DSS is received via a D2DSS resource #n among D2DSS resources included in the shortest period,

wherein the second D2DSS is transmitted via a D2DSS resource #n+1 among the D2DSS resources, and

wherein a gap is located between the D2DSS resource #n and the D2D resource #n+1.

2. The method of claim 1, wherein the shortest period is 40 ms.

3. The method of claim 1, wherein each of the D2DSS candidate periods is related to a scheduling assignment channel, a D2D data channel, or a discovery channel.

4. The method of claim 1, further comprising:

transmitting a D2D Shared Channel (D2DSCH) in a subframe in which the D2DSS is transmitted based on the shortest period.

5. A first user equipment (UE) for transmitting a device-to-device (D2D) synchronization signal (SS) in a wireless communication system, the first UE comprising:

a transmitter and receiver; and

a processor, operatively coupled to the transmitter and receiver,

wherein the processor is configured to;

control the receiver to receive information related to a plurality of D2DSS candidate periods, wherein each of the D2DSS candidate periods is different from each other;

determine whether to perform a D2D communication with a second UE,

wherein the first and the second UEs are out-of-coverage UEs;

based on the determination to perform the D2D communication with the second UE;

control the receiver to receive a first D2DSS from an in-coverage UE during a shortest period among the D2DSS candidate periods; and

control the receiver to transmit a second D2DSS during the shortest period,

wherein the first D2DSS is received via a D2DSS resource #n among D2DSS resources included in the shortest period,

wherein the second D2DSS is transmitted via a D2DSS resource #n+1 among the D2DSS resources, and

wherein a gap is located between the D2DSS resource #n and the D2D resource #n+1.

6. The first UE of claim 5, wherein the shortest period is 40 ms.

7. The first UE of claim 5, wherein each of the D2DSS candidate periods is related to a scheduling assignment channel, a D2D data channel, or a discovery channel.

8. The first UE of claim 5, wherein the processor is further configured to:

control the transmitter to transmit a D2D Shared Channel (D2DSCH) in a subframe in which the D2DSS is transmitted based on the shortest period.