Method for transmitting discovery message in wireless communication system and apparatus for same

• US 10,149,138 B2
• Filed: 11/28/2014
• Issued: 12/04/2018
• Est. Priority Date: 11/29/2013
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation), University R&DB Foundation
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Hakseong, Seong, Seonik, Lee, Kwangbok
• Primary Examiner(s): Chen, Peter
• Application Number:
  US15/022,160
• Publication Number:
  US 20160269885A1
• Time in Patent Office: 1,467 Days
• CPC Class Codes: H04L 27/18 Phase-modulated carrier systems, i.e. using phase-shift keying H04L27/32 takes precedence
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 72/121 for groups of terminals or users
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals

Abstract

A method for transmitting a discovery message in a wireless communication system supporting device-to-device (D2D) direct communication, the method performed by the device, includes: discovering a D2D synchronization signal; classifying one or more macros by using the strength of the discovered D2D synchronization signal; receiving macro resource allocation information from a base station of the classified macro; sensing a macro resource of the classified macro based on the received macro resource allocation information; determining a macro resource for selecting a discovery resource through the sensing result; determining a discovery resource for transmitting a discovery message in the determined macro resource; and transmitting the discovery message through the determined discovery resource.

Claims

1. A method, performed by a terminal, for transmitting a discovery signal in a wireless communication system supporting device-to-device (D2D) direct communication, the method comprising:

discovering a D2D synchronization signal;

classifying one or more macro base stations by using a strength of the discovered D2D synchronization signal;

receiving macro resource allocation information from the classified macro base stations;

sensing a macro resource of the classified macro base stations based on the received macro resource allocation information;

selecting the macro resource as a discovery resource based on the sensing of the macro resource;

transmitting the discovery signal through the discovery resource,

wherein the macro resource is selected based on a maximum summation of power values measured in the macro resource and a value indicating the number of other terminals which are anticipated to successfully receive the discovery signal.

2. The method of claim 1, wherein:

the classifying of the one or more macro base stations includes;

measuring strengths of D2D synchronization signals transmitted from multiple macro base stations;

comparing the measured strengths of the D2D synchronization signals and a predetermined threshold; and

classifying one or more macro base stations for transmitting D2D synchronization signals having strengths greater than the threshold.

3. The method of claim 1, wherein:

the macro resource is based on an equation given below;

4. The method of claim 1, further comprising:

receiving another discovery signal transmitted from another terminal through a resource other than the determined discovery resource.

5. The method of claim 4, further comprising:

reselecting a macro resource as the discovery resource based on the received discovery signal of the another terminal.

6. The method of claim 5, further comprising:

the macro resource is reselected based on an equation given below;

7. A terminal for transmitting a discovery signal in a wireless communication system supporting device-to-device (D2D) direct communication, the terminal comprising:

a radio frequency (RF) unit for transmitting and receiving a radio signal; and

a processor functionally connected with the RF unit,

wherein the processor;

discovers a D2D synchronization signal;

classifies one or more macro base stations by using a strength of the discovered D2D synchronization signal;

controls the RF unit to receive macro resource allocation information from the classified macro base stations;

senses a macro resource of the classified macro base stations based on the received macro resource allocation information;

selects the macro resource as a discovery resource based on the sensing of the macro resource;

controls the RF unit to transmit the discovery signal through the discovery resource,

wherein the processor selects the macro resource based on a maximum summation of power values measured in the macro resource and a value indicating the number of other terminals which are anticipated to successfully receive the discovery signal.

8. The terminal of claim 7, wherein the processor measures strengths of D2D synchronization signals transmitted from multiple macro base stations;

compares the measured strengths of the D2D synchronization signals and a predetermined threshold; and

classifies one or more macro base stations for transmitting D2D synchronization signals having strengths greater than the threshold.

9. The terminal of claim 7, wherein the processor controls the RF unit to receive the discover signal transmitted from another terminal through a resource other than the determined discovery resource.

10. The terminal of claim 9, wherein the processor reselects a macro resource as the discovery resource based on the received discovery signal of another terminal.