METHOD AND APPARATUS FOR PROVIDING COMMON TIME REFERENCE IN WIRELESS COMMUNICATION SYSTEM

• US 20140219270A1
• Filed: 02/03/2014
• Published: 08/07/2014
• Est. Priority Date: 02/01/2013
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ro, Sangmin, Ji, Hyoungju, Cho, Joonyoung, Kim, Younsun, Choi, Seunghoon, Kwak, Yongjun
• Granted Patent: US 9,807,716 B2
• Time in Patent Office: Days
• US Class Current: 370/350
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 56/002 Mutual synchronization
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A terminal and method of performing device-to-device (D2D) communication by a terminal in a wireless communication system is provided. The method includes determining if a signal including synchronization information is received via at least one of an uplink and a downlink; and when the signal including the synchronization information is not received, transmitting a synchronization information-containing signal.

Claims

1. A method of performing device-to-device (D2D) communication by a terminal in a wireless communication system, the method comprising:

determining if a signal including synchronization information is received via at least one of an uplink and a downlink; and

when the signal including the synchronization information is not received, transmitting a synchronization information-containing signal.

2. The method as claimed in claim 1, wherein determining if the signal including the synchronization information is received comprises:

determining if synchronization information is received via the downlink during an interval satisfying a first condition; and

determining if synchronization information is received via the uplink during an interval satisfying a second condition.

3. The method as claimed in claim 2, wherein determining if the synchronization information is received via the uplink comprises:

when the synchronization information is not received via the downlink, determining if synchronization information is received via the uplink during an interval satisfying the second condition.

4. The method as claimed in claim 2, wherein at least one of the first condition and the second condition comprises:

at least one of whether a certain period of time elapses, whether a certain number of attempts are performed, and whether a predetermined timer expires.

5. The method as claimed in claim 2, wherein at least one of the first condition and the second condition is differently set according to terminals, and is set such that a specific terminal transmits a signal including synchronization information earlier than other terminals.

6. The method as claimed in claim 1, further comprising:

when the signal including the synchronization information is received, performing the D2D communication, based on the received synchronization information.

7. The method as claimed in claim 1, wherein transmitting the synchronization information-containing signal comprises:

transmitting the synchronization information-containing signal when the terminal is permitted to transmit the synchronization information-containing signal, according to a configuration given to the terminal.

8. The method as claimed in claim 1, further comprising:

when the synchronization information is acquired, transmitting the synchronization information-containing signal, based on the acquired synchronization information.

9. The method as claimed in claim 8, wherein transmitting the synchronization information-containing signal comprises:

transmitting the synchronization information-containing signal in different manners according to directions of links via each of which the synchronization information is acquired.

10. The method as claimed in claim 1, wherein determining if the signal including the synchronization information is received comprises:

when signals including synchronization information are received via a plurality of uplinks, preferentially applying synchronization information included in a signal that is transmitted via an uplink by a terminal having acquired the synchronization information via a downlink.

11. A terminal for performing device-to-device (D2D) communication in a wireless communication system, the terminal comprising:

a transceiver that transmits and receives signals to and from other terminals and a base station; and

a controller configured to control the transceiver, determine if a signal including synchronization information is received via at least one of an uplink and a downlink, and transmit a synchronization information-containing signal when the signal including the synchronization information is not received.

12. The terminal as claimed in claim 11, wherein the controller

determines if synchronization information is received via the downlink during an interval satisfying a first condition;

and

determines if synchronization information is received via the uplink during an interval satisfying a second condition.

13. The terminal as claimed in claim 12, wherein, when the synchronization information is not received via the downlink, the controller determines if synchronization information is received via the uplink during an interval satisfying the second condition.

14. The terminal as claimed in claim 12, wherein at least one of the first condition and the second condition comprises:

at least one of whether a certain period of time elapses, whether a certain number of attempts are performed, and whether a predetermined timer expires.

15. The terminal as claimed in claim 12, wherein at least one of the first condition and the second condition is differently set according to terminals, and is set such that a specific terminal transmits a signal including synchronization information earlier than other terminals.

16. The terminal as claimed in claim 11, wherein, when the signal including the synchronization information is received, the controller performs the D2D communication, based on the received synchronization information.

17. The terminal as claimed in claim 11, wherein the controller transmits the synchronization information-containing signal when the terminal is permitted to transmit the synchronization information-containing signal, according to a configuration given to the terminal.

18. The terminal as claimed in claim 11, wherein, when the synchronization information is acquired, the controller transmits the synchronization information-containing signal, based on the acquired synchronization information.

19. The terminal as claimed in claim 18, wherein the controller transmits the synchronization information-containing signal in different manners according to direction of links via each of which the synchronization information is acquired.

20. The terminal as claimed in claim 11, wherein, when signals including synchronization information are received via a plurality of uplinks, the controller preferentially applies synchronization information included in a signal that is transmitted via an uplink by a terminal having acquired the synchronization information via a downlink.