METHOD FOR TRANSMITTING DOWNLINK SIGNAL AT A RELAY NODE IN A WIRELESS COMMUNICATION SYSTEM AND APPARATUS THEREFOR

• US 20150117300A1
• Filed: 11/08/2012
• Published: 04/30/2015
• Est. Priority Date: 07/15/2012
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation), SungKyunKwan University's Research & Business Foundation (SungKyunKwan University)
• Original Assignee: LG Electronics, Inc. (LG Corporation), SungKyunKwan University's Research & Business Foundation (SungKyunKwan University)
• Inventors: Nam, Sungsik, Choi, Wan, Seo, Hanbyul, Kim, Dongin
• Granted Patent: US 9,537,637 B2
• Time in Patent Office: Days
• US Class Current: 370/315
• CPC Class Codes: H04B 7/15 Active relay systems
• CPC Class Codes: H04B 7/15528 Control of operation parameters of a relay station to exploit the physical medium
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/1819 with retransmission of additional or different redundancy
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 2001/0097 Relays
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861

Abstract

A method for transmitting downlink signals at a source base station in a wireless communication system is disclosed. The method comprises transmitting a downlink signal to an end user and at least one relay; receiving a negative response signal from the end user; receiving a positive response signal and channel status information about a channel between the at least one relay and the end user, wherein the at least one relay overhears the negative response signal; and scheduling a specific relay having the best channel status of the at least one relay to re-transmitting the downlink signal to the end user.

Claims

1. A method for transmitting downlink signals at a source base station in a wireless communication system, the method comprising:

transmitting a downlink signal to an end user and at least one relay;

receiving a negative response signal from the end user;

receiving a positive response signal and channel status information about a channel between the at least one relay and the end user,

wherein the at least one relay overhears the negative response signal; and

scheduling a specific relay having the best channel status of the at least one relay to re-transmitting the downlink signal to the end user.

2. The method according to claim 1, wherein the at least one relay estimates the channel status information between the at least one relay and the end user, based on the overheard the negative response signal.

3. The method according to claim 1, wherein the at least one relay transmits the positive response signal and the channel status information if the at least one relay decodes the downlink signal correctly.

4. The method according to claim 1, wherein the step of scheduling the specific relay performs iteratively until receiving the positive response signal from the end user.

5. The method according to claim 1, wherein, if the end user decodes the re-transmitted downlink signal correctly, the end user transmits the positive response signal to both the source base station and the specific relay.

6. The method according to claim 1, wherein, if the end user decodes the re-transmitted downlink signal correctly, the end user transmits the positive response signal to the source base station.

7. The method according to claim 1, wherein the step of scheduling the specific relay performs iteratively on subframe basis.

8. The method according to claim 1, wherein the at least one relay is an user equipment (UE) relay.

9. A method for transmitting downlink signals at a relay in a wireless communication system, the method comprising:

receiving a downlink signal from a source base station;

overhearing a negative response signal which is transmitted from an end user to the source base station;

transmitting a positive response signal and channel status information about a channel between the relay and the end user if decoding the downlink signal correctly;

receiving scheduling information from the source base station; and

re-transmitting the downlink signal to the end user based on the scheduling information.

10. The method according to claim 9, wherein the relay has the best channel status among at least one relay including the relay.

11. The method according to claim 9, wherein the channel status information between the at least one relay and the end user is estimated based on the overheard the negative response signal.

12. The method according to claim 9, wherein the relay is an user equipment (UE) relay.