Downlink single-user multi-cell mimo systems for interference mitigation

• US 20100273492A1
• Filed: 04/27/2009
• Published: 10/28/2010
• Est. Priority Date: 04/27/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Zhang, Jianzhong, Liu, Lingjia
• Granted Patent: US 8,620,280 B2
• Time in Patent Office: Days
• US Class Current: 455/446
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04W 16/30 Special cell shapes, e.g. doughnuts or ring cells
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

A system and method for interference mitigation. The system and method includes a number of base stations configured to coordinate with each other to perform a joint transmission to one or more subscriber stations. The base stations allocate a portion of a frequency band for the joint transmission and jointly schedule the joint transmission. Further, the base stations are configured to select a common codebook or separate codebooks to perform the joint transmission. Thereafter, the joint transmission is performed wherein the one or more subscribers stations substantially simultaneously receive the joint transmission from each of the base stations.

Claims

1. For use in a wireless communications network, a subscriber station capable of receiving communications from a plurality of communications, said subscriber station comprising:

a transmitter configured to feedback channel related information to a plurality of cells;

a receiver configured to receive a coordinated joint transmission based on the channel related information from at least two cells.

2. The subscriber station as set forth in claim 1, wherein said at least two cells jointly schedule said coordinated joint transmission.

3. The subscriber station as set forth in claim 1, wherein said subscriber station is configured to request said coordinated joint transmission.

4. The subscriber station as set forth in claim 3, wherein said request is based on a channel performance measurement.

5. The subscriber station as set forth in claim 3, wherein at least one of said at least two cells is configured to accept or deny said request.

6. The subscriber station as set forth in claim 1, wherein said coordinated joint transmission comprises a semi-statistical configuration of a frequency band.

7. The subscriber station as set forth in claim 1, wherein said at least two cells are configured to jointly choose a preceding matrix.

8. The subscriber station as set forth in claim 1, wherein said subscriber station reports the channel related information jointly for at least two cells.

9. The subscriber station as set forth in claim 1, wherein said subscriber station reports the channel related information independently for at least two cells.

10. The subscriber station as set forth in claim 1, wherein said subscriber station performs diversity decoding on the coordinated joint transmission.

11. A wireless communications network comprising a plurality of base stations, each one of said base stations capable of wireless communications with a plurality of subscriber stations, at least two of said plurality of base stations comprising:

a controller configured to communicate with another base station via a base station connection; and

a transmitter, wherein said at least two base stations coordinate with each other to send a joint transmission to at least one of said plurality of subscriber stations.

12. The network as set forth in claim 11, wherein said at least two base stations jointly schedule said joint transmission.

13. The network as set forth in claim 11, wherein said joint transmission is allocated in a portion of a frequency band.

14. The network as set forth in claim 11, wherein at least one of said base stations receives a request for a joint transmission.

15. The network as set forth in claim 11, wherein said joint transmission is a multi-user multiple input multiple output transmission.

16. The network as set forth in claim 11, wherein said at least two base stations jointly choose a preceding matrix.

17. The network as set forth in claim 16, wherein at least one of said at least two base stations receives a report regarding a channel related information jointly for at least two base stations.

18. The network as set forth in claim 11, wherein said at least two base stations independently choose a preceding matrix.

19. The network as set forth in claim 18, wherein at least one of said at least two base stations receives a report regarding a channel related information independently for at least two base stations.

20. The network as set forth in claim 11, wherein at least one of said base stations receives a feedback signal from said subscriber station, said feedback signal comprising channel related information.

21. The network as set forth in claim 11, wherein at least one of said base stations performs diversity encoding on a number of streams in the coordinated joint transmission.

22. For use in a wireless communications network, a method for interference mitigation, the method comprising:

coordinating, by a first base station, a joint transmission to at least one subscriber station;

allocating a portion of a frequency band for the joint transmission;

transmitting, by the first base station, the joint transmission at a substantially same time and frequency that the joint transmission is transmitted by a second base station to the at least one subscriber station.

23. The method as set forth in claim 22, further comprising receiving a request, from the at least one subscriber station, for the joint transmission.

24. The method as set forth in claim 22, further comprising transmitting the joint transmission to a plurality of subscriber stations utilizing a multiple input multiple output transmission.

25. The method as set forth in claim 22, further comprising selecting, by the subscriber station, first channel related information for the first base station independent of a second channel related information for the second base station.

26. The method as set forth in claim 22, further comprising selecting, by the subscriber station, channel related information for a joint channel of the first and second base stations.