System and scheduler for intercell interference cancellation

• US 20080009256A1
• Filed: 06/18/2007
• Published: 01/10/2008
• Est. Priority Date: 06/19/2006
• Status: Active Grant

• Current Assignee: Intellectual Ventures II LLC (Intellectual Ventures LLC)
• Original Assignee: IPWireless Inc. (NVIDIA Corporation)
• Inventors: Anderson, Nicholas
• Granted Patent: US 8,725,077 B2
• Time in Patent Office: Days
• US Class Current: 455/296
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04J 11/005 of intercell interference
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0028 Variable division signaling therefor H04L5/0092
• 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: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

Embodiments of the invention provide a controller, in a cellular wireless network for cancellation of interference from neighboring cells. Logic in the controller determines channel quality of a radio channel between a first base station and a UE. Scheduling logic causes the first base station and a second base station to adjust the number of data streams used for communication within a time period, as a function of the channel quality. Other embodiments provide an apparatus for reducing interference in a receiver that receives N data streams. Signal processing logic receives the N data streams, where N-M of the data streams represent interference with respect to M desired data streams, and cancels the N-M data streams so as to receive the M desired data streams. The N data streams may be received from multiple base stations, or multiple UEs.

Claims

1. A controller in a cellular wireless network, the controller comprising:

logic for determining channel quality of a radio channel between a first base station and a user equipment (UE); and

scheduling logic for causing the first base station and a second base station to adjust the number of data streams used for communication within a time period, as a function of the channel quality.

2. The controller of claim 1, wherein the channel quality is represented by a carrier-to-interference ratio.

3. The controller of claim 1, wherein the logic for determining the channel quality is operable to receive a signal quality report from the UE indicative of the quality of signals received by the UE from the first base station.

4. The controller of claim 1, wherein

the logic for determining channel quality is operable to determine a first channel quality for the first base station communicating with a first UE, and a second channel quality for the second base station communicating with a second UE, the first and second base station serving adjacent cells;

and

the scheduling logic is operable to cause the first and second base stations to adjust the number of data streams based upon the poorest channel quality of the first and second channel qualities.

5. The controller of claim 1, wherein the scheduling logic is operable to schedule designated resources corresponding to the channel quality.

6. The controller of claim 1, wherein the scheduling logic is operable to

instruct the first and second base stations to reduce the number of data streams used by each of the base stations in response to a low channel quality;

and

instruct the first and second base stations to increase the number of data streams used by each of the base stations in response to a high channel quality.

7. The controller of claim 6, wherein the low channel quality is indicative of the channel quality falling below a threshold, and the high channel quality is indicative of the channel quality exceeding a threshold.

8. The controller of claim 1, wherein the first base station is associated with a serving cell, and the second base station represents an interfering cell

9. The controller of claim 1, wherein the data streams are substantially time-aligned.

10. The controller of claim 9, wherein substantial time-alignment of the data streams is based upon the cyclic prefix period in an Orthogonal Frequency Division Multiplexing (OFDM) symbol.

11. The controller of claim 1, wherein the data streams are subject to OFDM modulation.

12. The controller of claim 1, wherein the data streams are subject to Code Division Multiple Access (CDMA) modulation.

13. A radio network controller (RNC) in a radio access network, wherein the RNC comprises the controller of claim 1.

14. A base station in a wireless communications network, wherein the base station comprises the controller of claim 1.

15. An access gateway (aGW) in a wireless communications network, wherein the aGW comprises the controller of claim 1.

16. A radio resource management (RRM) server in a wireless communications network, wherein the RRM server comprises the controller of claim 1.

17. In a receiver for receiving N data streams in a cellular wireless network, an apparatus for reducing interference, the apparatus comprising signal processing logic for:

receiving the N data streams, wherein N-M of the data streams represent interference with respect to M desired data streams; and

cancelling the N-M data streams so as to receive the M desired data streams,

wherein the logic for receiving the N data streams is operable to receive the N data streams.

18. The apparatus of claim 17, wherein the receiver resides in a user equipment (UE), and the signal processing logic is further operable to:

provide a signal quality report to at least one base station, the signal quality report indicative of the quality of a channel between the UE and the at least one base station; and

receive at least one instruction to communicate M desired data streams with the at least one base station, wherein the at least one instruction is based upon the signal quality report.

19. The apparatus of claim 17, wherein the receiver is a UE.

20. The apparatus of claim 17, wherein the receiver resides in a base station.

21. The apparatus of claim 17, wherein the receiver includes a multiple-input multiple-output (MIMO) receiver.

22. The apparatus of claim 17, wherein the N data streams are substantially time-aligned.

23. The apparatus of claim 17, wherein N represents a maximum data stream capacity of the receiver.

24. The apparatus of claim 17, wherein the data streams are subject to OFDM modulation.

25. The apparatus of claim 17, wherein the data streams are subject to CDMA modulation.

26. The apparatus of claim 17, wherein the N data streams are from a plurality of base stations.

27. The apparatus of claim 17, wherein the N data streams are from a plurality of UEs.

28. A method for scheduling resources in a cellular wireless network, the method comprising:

determining channel quality of a radio channel between a first base station and a UE; and

causing the first base station and a second base station to adjust the number of data streams used for communication within a time period, as a function of the channel quality.

29. The method of claim 28, wherein causing the first base station and a second base station to adjust the number of data streams used for communication within a time period includes scheduling designated resources corresponding to the channel quality.

30. The method of claim 28, wherein determining the channel quality comprises receiving a signal quality report from the UE indicative of the quality of signals received by the UE from the first base station.

31. The method of claim 28, wherein the first base station is associated with a serving cell, and the second base station represents an interfering cell

32. The method of claim 28, wherein the data streams are substantially time-aligned.

33. A computer readable medium encoded with program instructions for carrying out the method of claim 28.

34. In a receiver for receiving N data streams in a cellular wireless network, a method for reducing interference, the method comprising:

receiving the N data streams, wherein N-M of the data streams represent interference with respect to M desired data streams; and

cancelling the N-M data streams so as to receive the M desired data streams,

wherein the logic for receiving the N data streams is operable to receive the N data streams from a plurality of base stations.

35. The method of claim 34, wherein the receiver resides in a UE, the method further comprising:

providing a signal quality report to at least one base station, the signal quality report indicative of the quality of a channel between the UE and the at least one base station; and

receiving at least one instruction to communicate M desired data streams with the at least one base station, wherein the at least one instruction is based upon the signal quality report.

36. A computer readable medium encoded with program instructions for carrying out the method of claim 34.