METHOD FOR AVOIDING INTER-CELL INTERFERENCE IN WIRELESS ACCESS SYSTEM

• US 20130242855A1
• Filed: 10/06/2011
• Published: 09/19/2013
• Est. Priority Date: 12/02/2010
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation), Sungkyunkwan University Foundation For Corporate Collaboration (SungKyunKwan University)
• Original Assignee: LG Electronics, Inc. (LG Corporation), Sungkyunkwan University Foundation For Corporate Collaboration (SungKyunKwan University)
• Inventors: Kim, Hakseong, Shin, Yoan, Shin, Ohsoon, Yang, Mochan, Yoo, Sungcheol
• Granted Patent: US 9,179,468 B2
• Time in Patent Office: Days
• US Class Current: 370/315
• CPC Class Codes: H04B 7/2656 for structure of frame, burst
• CPC Class Codes: H04J 11/005 of intercell interference
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 2001/0097 Relays
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

According to the disclosure of the present invention, provided is a method for operating a relay node (RN) to avoid an inter-cell interference (ICI) in a wireless access system. The method includes: overhearing the downlink signal transmitted by a plurality of base stations to terminals within the coverage area of each base station in an n^th subframe; decoding the overheard downlink signal from an n+1^th subframe to an n+3^th subframe and sharing the RN through the plurality of base stations; overhearing the reply to the downlink signal transmitted by the terminals to each base station in an n+4^th subframe; reallocating a resource block allocated to the terminals in the n^th subframe if there is at least one negative reply NACK in the replies to the downlink signal transmitted by the terminals; and transmitting control information representing the reallocated resource block to each base station.

Claims

1. A method for operating a relay node (RN) to avoid an inter-cell interface (ICI) in a wireless access system, the method comprising:

overhearing a downlink signal transmitted by a plurality of base stations to terminals within a coverage area of each base station in an n^th sub-frame;

decoding the overheard downlink signal from an n+1^th sub-frame to an n+3^th sub-frame and sharing the RN through the plurality of base stations;

overhearing a response to the downlink signal transmitted by the terminals to each base station in an n+4^th sub-frame;

reallocating a resource block allocated to the terminals in the n^th sub-frame if there is at least one negative acknowledgement NACK in the responses to the downlink signal transmitted by the terminals, wherein the response is a positive acknowledgement ACK or a negative acknowledgement NACK;

transmitting control information representing the reallocated resource block to each base station; and

transmitting, in an n+8^th sub-frame, the downlink signal transmitted to the terminals in the n^th sub-frame, in accordance with the control information.

2. The method of claim 1, wherein the transmitting of the control information to each base station comprises:

comparing resource blocks allocated to terminals within a coverage area of the relay node through the downlink signal with each other to determine whether collision resource block is included in the resource blocks; and

reallocating a resource to the resource block in which the collision occurs when the collision resource block is included in the resource blocks.

3. The method of claim 2, wherein the reallocating of the resource comprises exchanging the collision resource block for resource blocks to be allocated to terminals outside the coverage area of the relay node.

4. The method of claim 3, wherein the exchanging of the collision resource block comprises:

comparing a Signal-to-Interference plus Noise Ratio (SINR) of the collision resource block with SINRs of the resource blocks to be allocated to terminals outside the coverage area of the relay node, respectively; and

determining a resource block having a smallest difference between the SINRs as a resource block to be exchanged.

5. The method of claim 1, wherein the plurality of base stations comprises three base stations, and

the relay node comprises a shard relay node (SRN) shared by the three base stations.

6. The method of claim 1, wherein the downlink signal transmitted in the nth sub-frame comprises a physical downlink control channel (PDCCH) and a physical uplink control channel (PDSCH).

7. The method of claim 1, wherein the downlink signal transmitted to the terminals in the nth sub-frame comprises a physical downlink shared channel (PDSCH).

8. The method of claim 1, wherein the relay node uses the plurality of base stations and X2 signaling.

9. A method for operating a relay node (RN) to avoid an inter-cell interface (ICI) in a wireless access system, the method comprising:

transmitting a downlink signal to a terminal within a coverage area of the base station in an nth sub-frame;

receiving a response to the downlink signal from the terminal in an n+4th sub-frame, wherein the response is a positive acknowledgement ACK or a negative acknowledgement NACK;

receiving control information representing that a procedure of reallocating a resource to the terminal transmitting the negative acknowledgement NACK to the downlink signal is required from the relay node;

reallocating a resource block allocated in the nth sub-frame to the terminal transmitting the negative acknowledgement NACK to the downlink signal based on the received control information; and

retransmitting, in an n+8th sub-frame, the downlink signal transmitted to the terminal in the nth sub-frame, according to the reallocated resource block.

10. The method of claim 9, wherein the reallocating of the resource block allocated in the nth sub-frame comprises:

comparing resource blocks allocated to terminals within a coverage area of the relay node through the downlink signal with each other to determine whether collision resource block is included in the resource blocks; and

reallocating a resource to the resource block in which the collision occurs when the collision resource block is included in the resource blocks.

11. The method of claim 10, wherein the reallocating of the resource comprises exchanging the collision resource block for resource blocks to be allocated to terminals outside the coverage area of the relay node.

12. The method of claim 11, wherein the exchanging of the collision resource block comprises:

comparing a Signal-to-Interference plus Noise Ratio (SINR) of the collision resource block with SINRs of the resource blocks to be allocated to terminals outside the coverage area of the relay node, respectively; and

determining a resource block having a smallest difference between the SINRs as a resource block to be exchanged.

13. The method of claim 9, wherein the relay node comprises a shard relay node (SRN) shared by a plurality of base stations.

14. The method of claim 9, wherein the downlink signal transmitted in the nth sub-frame comprises a physical downlink control channel (PDCCH) and a physical uplink control channel (PDSCH).

15. The method of claim 9, wherein the downlink signal transmitted to the terminals in the nth sub-frame comprises a physical downlink shared channel (PDSCH).