Systems and Methods for Parallel Signal Cancellation

• US 20110096767A1
• Filed: 12/13/2010
• Published: 04/28/2011
• Est. Priority Date: 09/20/2002
• Status: Active Grant

• Current Assignee: III Holdings 1, LLC (Intellectual Ventures LLC)
• Original Assignee: Rambus Inc.
• Inventors: Narayan, Anand P., Thomas, John K., Olson, Eric S.
• Granted Patent: US 9,544,044 B2
• Time in Patent Office: Days
• US Class Current: 370/342
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04B 1/1081 Reduction of multipath noise by equalising H04B7/005
• CPC Class Codes: H04B 1/126 having multiple inputs, e.g. auxiliary antenna for receiving interfering signal aerials in general H01Q
• CPC Class Codes: H04B 1/7105 Joint detection techniques, e.g. linear detectors
• CPC Class Codes: H04B 1/7107 Subtractive interference cancellation
• CPC Class Codes: H04B 1/7117 Selection, re-selection, allocation or re-allocation of paths to fingers, e.g. timing offset control of allocated fingers
• CPC Class Codes: H04B 1/712 Weighting of fingers for combining, e.g. amplitude control or phase rotation using an inner loop
• CPC Class Codes: H04B 2001/1045 Adjacent-channel interference
• CPC Class Codes: H04B 2201/70719 CDMA2000
• CPC Class Codes: H04B 2201/70979 Fat finger issues in RAKE receivers
• CPC Class Codes: H04B 7/0678 using different spreading codes between antennas code allocation H04J13/16
• CPC Class Codes: H04B 7/0891 Space-time diversity rake receivers H04B1/7115; space-time decoding H04L1/0631
• CPC Class Codes: H04J 13/0022 PN, e.g. Kronecker
• CPC Class Codes: H04J 13/20 having an orthogonal variable spreading factor [OVSF]

Abstract

A multi-mode receiver includes a channel decomposition module (e.g., a Rake receiver) for separating a received signal into multipath components, an interference selector for selecting interfering paths and subchannels, a synthesizer for synthesizing interference signals from selected sub channel symbol estimates, and an interference canceller for cancelling selected interference in the received signal. At least one of the channel decomposition module, the synthesizer, and the interference canceller are configurable for processing multi-mode signals.

Claims

1. A processing engine, comprising:

one or more matrix generators, wherein each of the one or more matrix generators is configured for generating a matrix comprising elements of an interfering signal selected for suppression;

a processor communicatively coupled to the one or more matrix generators and configured for generating one or more suppression operators; and

one or more applicators, wherein each applicator is communicatively coupled to the processor and configured for applying at least one of the one or more suppression operators to an input signal to substantially suppress at least one of the interfering signals.

2. The processing engine of claim 1, wherein the processing engine is configurable with a receiver and wherein the processing engine further comprises a connection element configured for receiving one or more output signals from the one or more applicators and for selecting one or more of the one or more output signals as inputs to one or more processing fingers of the receiver.

3. The processing engine of claim 2, wherein the connection element comprises one or more selectors configured for receiving one or more of the output signals and for selecting one or more of the output signals as inputs to one or more of the processing fingers.

4. The processing engine of claim 3, wherein at least one of the one or more selectors is further configured for receiving a digitized signal comprising one or more Code Division Multiple Access signals as an input to one of the processing fingers.

5. The processing engine of claim 3, wherein at least one of the one or more selectors is further configured for receiving a digitized signal comprising one or more Wideband Code Division Multiple Access signals as an input to one of the processing fingers.

6. The processing engine of claim 3, wherein each of the one or more selectors is further configured for receiving a digitized signal comprising one or more Global Positioning System signals as an input to one of the processing fingers.

7. The processing engine of claim 3, wherein the output signals are interference suppressed signals.

8. The processing engine of claim 1, wherein each of the suppression operators comprises the form:

y′

=y−

S(S^TS)<sup>−

1</sup>S^Ty,

where y′

is an output suppressed signal, y is a received signal, S is one of the matrices and S^T is a transpose of said one of the matrices.

9. The processing engine of claim 1, further comprising an interference selector configured for selecting at least one interfering signal as an input to the one or more matrix generators.

10. The processing engine of claim 9, wherein the interference selector is further configured for providing on-time interfering PN codes of the interfering signals to the one or more matrix generators.

11. The processing engine of claim 9, wherein the interference selector selects the interfering signals based on a pre-determined criteria selected from a group consisting of amplitude, timing offset, phase and code sequence.

12. A method of suppressing interference, comprising:

generating one or more matrices, each of the one or more matrix comprising elements of an interference signal selected for suppression;

generating one or more suppression operators from the one or more matrices; and

applying the one or more suppression operators in parallel to an input signal to substantially suppress at least one of the interference signals.

13. The method of claim 12, wherein applying comprises substantially suppressing said one of the interfering signals according to the form:

y′

=y−

S(S^TS)<sup>−

1</sup>S^Ty,

where y′

is an output suppressed signal, y is a received signal, S is one of the matrices and S^T is a transpose of said one of the matrices.

14. The method of claim 12, further comprising selecting one or more interference signals for input to the one or more matrices.

15. The method of claim 12, further comprising providing one or more on-time interfering PN codes of the interfering signals to the matrices in response to selecting.

16. The method of claim 12, further comprising selecting one or more output signals generated in response to applying, for assignment of the one or more output signals to one or more processing fingers of a receiver.

17. The method of claim 16, further comprising transferring the one or more output signals to the one or more processing fingers in response to selecting said output signals as input signals to the processing fingers.

18. The method of claim 16, wherein the one or more output signals are interference suppressed signals.

19. The method of claim 12, further comprising receiving a Code Division Multiple Access signal.

20. The method of claim 12, further comprising receiving a Wideband Code Division Multiple Access signal.

21. The method of claim 12, further comprising receiving a Global Positioning System signal.

22. A system for suppressing interference, comprising:

means for generating one or more matrices, each matrix comprising elements of an interference signal selected for suppression;

means for generating one or more suppression operators from the one or more matrices; and

means for applying the one or more suppression operators in parallel to an input signal to substantially suppress at least one of the interference signals.

23. The system of claim 22, wherein the means for applying comprises means for substantially suppressing said at least one of the interfering signals according to the form:

y′

=y−

S(S^TS)<sup>−

1</sup>S^Ty,

where y′

is an output suppressed signal, y is a received signal, S is one of the matrices and S^T is a transpose of said one of the matrices.

24. The system of claim 22, further comprising means for selecting one or more interference signals for input to the one or more matrices.

25. The system of claim 22, further comprising means for providing on-time interfering PN codes of one or more interfering signals to the one or more matrices in response to selecting.

26. The system of claim 22, further comprising means for selecting one or more output signals generated in response to applying, for assignment of the one or more output signals to one or more processing fingers of a receiver.

27. The system of claim 26, further comprising means for transferring one or more output signals to the one or more processing fingers in response to selecting said output signals.

28. The system of claim 26, wherein the one or more output signals are interference suppressed signals.

29. The system of claim 22, further comprising means for receiving a Code Division Multiple Access signal.

30. The system of claim 25, further comprising means for receiving a Wideband Code Division Multiple Access signal.

31. The system of claim 22, further comprising means for receiving a Global Positioning System signal.

32. A mobile handset, comprising:

a receiver configured for receiving a signal; and

a processing engine communicatively coupled to the receiver and comprising

one or more matrix generators, wherein each of the one or more matrix generators is configured for generating a matrix comprising elements of an interfering signal selected for suppression;

a processor communicatively coupled to the one or more matrix generators and configured for generating one or more suppression operators; and

one or more applicators, wherein each of the one or more applicators is communicatively coupled to the processor and configured for applying at least one of the suppression operators to an input signal to substantially suppress at least one of the interfering signals.

33. The mobile handset of claim 32, wherein the processing engine further comprises a connection element configured for receiving output signals from the one or more applicators and for selecting one or more output signals as inputs to one or more processing fingers of the receiver.

34. The mobile handset of claim 33, wherein the connection element comprises one or more selectors configured for receiving one or more output signals and for selecting one or more of the one or more output signals as inputs to one or more of the processing fingers.

35. The mobile handset of claim 34, wherein one or more of the one or more selectors is further configured for receiving a digitized signal comprising one or more Code Division Multiple Access signals as one of the inputs to one of the processing fingers.

36. The mobile handset of claim 34, wherein one or more of the one or more selectors is further configured for receiving a digitized signal comprising one or more Wideband Code Division Multiple Access signals as one of the inputs to one of the processing fingers.

37. The mobile handset of claim 34, wherein one or more of the one or more selectors is further configured for receiving a digitized signal comprising one or more Global Positioning System signals as one of the inputs to one of the processing fingers.

38. The mobile handset of claim 33, wherein the output signals are interference suppressed signals.

39. The mobile handset of claim 32, wherein at least one of the suppression operators comprises the form:

y′

=y−

S(S^TS)<sup>−

1</sup>S^Ty,

where y′

is an output suppressed signal, y is a received signal, S is one of the matrices and S^T is a transpose of said one of the matrices.

40. The mobile handset of claim 32, further comprising an interference selector configured for selecting one or more interfering signals as inputs to the one or more matrix generators.

41. The mobile handset of claim 40, wherein the interference selector is further configured for providing on-time interfering PN codes of the one or more interfering signals to the one or more matrix generators.

42. The mobile handset of claim 40, wherein the interference selector selects the interfering signals based on a pre-determined criteria selected from a group consisting of amplitude, timing offset, phase and code sequence.

43. The mobile handset of claim 32, wherein the signal comprises a Code Division Multiple Access signal.

44. The mobile handset of claim 32, wherein the signal comprises a Wideband Code Division Multiple Access signal.

45. The mobile handset of claim 32, wherein the signal comprises a Global Positioning System signal.