Interference cancellation in a signal

• US 6,711,219 B2
• Filed: 11/19/2001
• Issued: 03/23/2004
• Est. Priority Date: 12/04/2000
• Status: Expired due to Term

• Current Assignee: III Holdings 1, LLC
• Original Assignee: TensorComm, Inc. (Rambus Inc.)
• Inventors: Thomas, John K., Kober, Woody, Olson, Eric, Krumvieda, Kent
• Primary Examiner(s): Tran, Khai
• Application Number:
  US09/988,218
• Publication Number:
  US 20040017867A1
• Time in Patent Office: 855 Days
• Field of Search: 375/346, 375/148, 375/150, 375/347, 375/316, 375/293, 375/343, 455/269, 455/272, 455/273, 370/335, 370/342, 370/320, 370/441
• US Class Current: 375/346
• CPC Class Codes: H04B 1/7103 the interference being multiple access interference
• 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 2001/70706 using a code tracking loop, e.g. a delay locked loop

Abstract

A communication system having a forward link and/or reverse link comprising: at least one base station which transmits multiple radio frequency (RF) signals; and a mobile station, the mobile station including: a receiver for receiving the RF signals; means for converting the RF signal to an intermediate frequency (IF) signal; means for sampling the IF signal to generate a digital signal, the digital signal having a data component and an interference component; means for canceling co-channel and or cross-channel interference in the digital signal by projecting the IF signal into a subspace orthogonal to a subspace of the interference component and multiplying this projection with the digital signal; and means for acquisition and tracking of the digital signal.

Claims

1. A communication system having a forward link comprising:

a base station which transmits multiple radio frequency (RF) signals; and

at least one mobile station, said mobile station including;

a receiver for receiving said RF signals;

means for converting said RF signal to an intermediate frequency (IF) analog signal;

means for sampling said IF analog Signal to generate a digital IF signal, said digital signal having a data component and an interference component;

means for canceling co-channel interference in said digital signal by projecting said digital signal onto a subspace orthogonal to a subspace of said interference component and multiplying this projection with said digital signal; and

means for acquisition and tracking of said projected digital signal.

2. The communication system recited in claim 1, wherein said intermediate frequency (IF) analog signal includes base band.

3. The communication system recited in claim 1, wherein said receiver comprises multiple fingers.

4. The communication system recited in claim 3, wherein said data component from one finger is treated as interference in at least one other finger of said multiple fingers.

5. The communication system recited in claim 3, wherein said data component from a first finger is treated as interference in at least a second finger of said multiple fingers.

6. The communication system recited in claim 5, wherein said data component from said first and second fingers are treated as interference in at least one other finger of said multiple fingers.

7. A mobile station, said mobile station for receiving at least two radio frequency (RF) signals from the same source and comprising:

a receiver for receiving said RF signals;

means for converting said RF signal to an intermediate frequency (IF) analog signal;

means for sampling said IF analog Signal to generate a digital IF signal, said digital signal having a data component and an interference component;

means for canceling co-channel interference in said digital signal by projecting said digital signal onto a subspace orthogonal to a subspace of said interference component and multiplying this projection with said digital signal; and

means for acquisition and tracking of said projected digital signal.

8. The mobile station recited in claim 7, wherein said intermediate frequency (IF) analog signal includes base band.

9. The mobile station recited in claim 7, wherein said receiver comprises multiple fingers.

10. The mobile station recited in claim 9, wherein said data component from one finger is treated as interference in at least one other finger of said multiple fingers.

11. The mobile station recited in claim 10, wherein said data component from a first finger is treated as interference in at least a second finger of said multiple fingers.

12. The mobile station recited in claim 11, wherein said data component from said first and second fingers are treated as interference in at least one other finger of said multiple fingers.

13. A method for receiving signals in a receiver having at least one receiver circuit, the method comprising the steps of:

receiving at least two radio frequency (RF) signals from the same source;

converting said RF signal to an intermediate frequency (IF) analog signal;

sampling said IF analog Signal to generate a digital IF signal, said digital signal having a data component and an interference component; and

canceling co-channel interference in said digital signal by projecting said digital signal onto a subspace orthogonal to a subspace of said interference component and multiplying this projection with said digital signal.

14. The method recited in claim 13, further comprising the steps of repeating the above steps for each finger in said receiver.

15. The method recited in claim 14, wherein said data component from one finger of said receiver is treated as interference in at least one other finger of said multiple fingers.

16. The method recited in claim 14, wherein said data component from said first and second fingers are treated as interference in at least one other finger of said multiple fingers.

17. A communication system having a reverse link comprising:

at least one mobile station which transmits radio frequency (RF) signals; and

at least one base station, said base station including;

a receiver for receiving at least two RF signals from said mobile station;

means for converting said RF signal to an intermediate frequency (IF) analog signal;

means for sampling said IF analog Signal to generate a digital IF signal, said digital signal having a data component and an interference component;

means for canceling co-channel interference in said digital signal by projecting said digital signal onto a subspace orthogonal to a subspace of said interference component and multiplying this projection with said digital signal; and

means for acquisition and tracking of said projected digital signal.

18. The communication system recited in claim 17, wherein said intermediate frequency (IF) analog signal includes base band.

19. The communication system recited in claim 17, wherein said receiver comprises multiple fingers.

20. The communication system recited in claim 19, wherein said data component from one finger is treated as interference in at least one other finger of said multiple fingers.

21. The communication system recited in claim 19, wherein said data component from a first finger is treated as interference in at least a second finger of said multiple fingers.

22. The communication system recited in claim 21, wherein said data component from said first and second fingers are treated as interference in at least one other finger of said multiple fingers.

23. A base station, said base station for receiving at least two radio frequency (RF) signals from the same source and comprising:

a receiver for receiving said RF signals;

means for converting said RF signal to an intermediate frequency (IF) analog signal;

means for sampling said IF analog Signal to generate a digital IF signal, said digital signal having a data component and an interference component;

means for canceling co-channel interference in said digital signal by projecting said digital signal onto a subspace orthogonal to a subspace of said interference component and multiplying this projection with said digital signal; and

means for acquisition and tracking of said projected digital signal.

24. The base station recited in claim 23, wherein said intermediate frequency (IF) analog signal includes base band.

25. The base station recited in claim 23, wherein said receiver comprises multiple fingers.

26. The base station recited in claim 25, wherein said data component from one finger is treated as interference in at least one other finger of said multiple fingers.

27. The base station recited in claim 26, wherein said data component from a first finger is treated as interference in at least a second finger of said multiple fingers.

28. The base station recited in claim 27, wherein said data component from said first and second fingers are treated as interference in at least one other finger of said multiple fingers.

29. A method for receiving signals in a receiver having at least one receiver circuit, the method comprising the steps of:

receiving at least two radio frequency (RF) signals broadcast from one mobile receiver;

converting said RF signal to an intermediate frequency (IF) analog signal;

sampling said IF analog Signal to generate a digital IF signal, said digital signal having a data component and an interference component; and

canceling co-channel interference in said digital signal by projecting said IF digital signal onto a subspace orthogonal to a subspace of said interference component and multiplying this projection with said digital signal.

30. The method recited in claim 29, further comprising the steps of repeating the above steps for each finger in said receiver.

31. The method recited in claim 30, wherein said data component from one finger of said receiver is treated as interference in at least one other finger of said multiple fingers.

32. The method recited in claim 30, wherein said data component from first and second fingers are treated as interference in at least one other finger of said multiple fingers.

33. A communication system having a forward link comprising:

at least one base station which transmits radio frequency (RF) signals; and

at least one mobile station, said mobile station including;

a receiver for receiving said RF signals;

means for converting said RF signal to an intermediate frequency (IF) analog signal;

means for sampling said IF analog Signal to generate an IF digital signal, said digital signal having a data component and an interference component;

means for canceling cross-channel interference in said digital signal by projecting said digital signal onto a subspace orthogonal to a subspace of said interference component and multiplying this projection with said digital signal; and

means for acquisition and tracking of said projected digital signal.

34. The communication system recited in claim 33, wherein said intermediate frequency (IF) analog signal includes base band.

35. The communication system recited in claim 33, wherein said receiver comprises multiple fingers.

36. The communication system recited in claim 35, wherein said data component from one finger is treated as interference in at least one other finger of said multiple fingers.

37. The communication system recited in claim 35, wherein said data component from a first finger is treated as interference in at least a second finger of said multiple fingers.

38. The communication system recited in claim 37, wherein said data component from said first and second fingers are treated as interference in at least one other finger of said multiple fingers.

39. A mobile station, said mobile station for receiving a radio frequency (RF) signal and comprising:

a receiver for receiving said RF signals;

means for converting said RF signal to an intermediate frequency (IF) analog signal;

means for sampling said IF analog Signal to generate a digital IF signal, said digital signal having a data component and an interference component;

means for canceling cross-channel interference in said digital signal by projecting said digital signal onto a subspace orthogonal to a subspace of said interference component and multiplying this projection with said digital signal; and

means for acquisition and tracking of said projected digital signal.

40. The mobile station recited in claim 39, wherein said intermediate frequency (IF) analog signal includes base band.

41. The mobile station recited in claim 39, wherein said receiver comprises multiple fingers.

42. The mobile station recited in claim 41, wherein said data component from one finger is treated as interference in at least one other finger of said multiple fingers.

43. The mobile station recited in claim 42, wherein said data component from a first finger is treated as interference in at least a second finger of said multiple fingers.

44. The mobile station recited in claim 43, wherein said data component from said first and second fingers are treated as interference in at least one other finger of said multiple fingers.

45. A method for receiving signals in a receiver having at least one receiver circuit, the method comprising the steps of:

receiving at least one radio frequency (RF) signal;

converting said RF signal to an intermediate frequency (IF) analog signal;

sampling said IF analog Signal to generate a digital IF signal, said digital signal having a data component and an interference component; and

canceling cross-channel interference in said digital signal by projecting said digital signal onto a subspace orthogonal to a subspace of said interference component and multiplying this projection with said digital signal.

46. The mobile station recited in claim 45, wherein said intermediate frequency (IF) analog signal includes base band.

47. The mobile station recited in claim 45, wherein said receiver comprises multiple fingers.

48. The method recited in claim 45, further comprising the steps of repeating the above steps for each finger in said receiver.

49. The method recited in claim 46, wherein said data component from one finger of said receiver is treated as interference in at least one other finger of said multiple fingers.

50. The method recited in claim 46, wherein said data component from first and second fingers are treated as interference in at least one other finger of said multiple fingers.

51. A communication system having a reverse link comprising:

at least one mobile station which transmits radio frequency (RF) signals; and

at least one base station, said base station including;

a receiver for receiving said RF signals;

means for converting said RF signal to an intermediate frequency (IF) analog signal;

means for sampling said IF analog Signal to generate a digital IF signal, said digital signal having a data component and an interference component;

means for canceling cross-channel interference in said digital signal by projecting said digital signal onto a subspace orthogonal to a subspace of said interference component and multiplying this projection with said digital signal; and

means for acquisition and tracking of said projected digital signal.

52. The communication system recited in claim 51, wherein said intermediate frequency (IF) analog signal includes base band.

53. The communication system recited in claim 51, wherein said receiver comprises multiple fingers.

54. The communication system recited in claim 53, wherein said data component from one finger is treated as interference in at least one other finger of said multiple fingers.

55. The communication system recited in claim 53, wherein said data component from a first finger is treated as interference in at least a second finger of said multiple fingers.

56. The communication system recited in claim 55, wherein said data component from said first and second fingers are treated as interference in at least one other finger of said multiple fingers.

57. A base station, said base station for receiving at least two radio frequency (RF) signals and comprising:

a receiver for receiving said RF signals;

means for converting said RF signal to an intermediate frequency (IF) analog signal;

means for sampling said IF analog Signal to generate a digital IF signal, said digital signal having a data component and an interference component;

means for canceling cross-channel interference in said digital signal by projecting said digital signal onto a subspace orthogonal to a subspace of said interference component and multiplying this projection with said digital signal; and

means for acquisition and tracking of said projected digital signal.

58. The base station recited in claim 57, wherein said intermediate frequency (IF) analog signal includes base band.

59. The base station recited in claim 57, wherein said receiver comprises multiple fingers.

60. The base station recited in claim 59, wherein said data component from one finger is treated as interference in at least one other finger of said multiple fingers.

61. The base station recited in claim 60, wherein said data component from a first finger is treated as interference in at least a second finger of said multiple fingers.

62. The base station recited in claim 61, wherein said data component from said first and second fingers are treated as interference in at least one other finger of said multiple fingers.

63. A method for receiving signals in a receiver having at least one receiver circuit, the method comprising the steps of:

receiving at least one radio frequency (RF) signal broadcast from at least one mobile receiver;

converting said RF signal to an intermediate frequency (IF) analog signal;

sampling said IF analog Signal to generate a digital IF signal, said digital signal having a data component and an interference component; and

means for canceling cross-channel interference in said digital signal by projecting said digital signal onto a subspace orthogonal to a subspace of said interference component and multiplying this projection with said digital signal.

64. The method recited in claim 63, further comprising the steps of repeating the above steps for each finger in said receiver.

65. The method recited in claim 64, wherein said data component from one finger of said receiver is treated as interference in at least one other finger of said multiple fingers.

66. The method recited in claim 64, wherein said data component from first and second fingers are treated as interference in at least one other finger of said multiple fingers.

67. A communication system having a forward link comprising:

at least one base station which transmits multiple radio frequency (RF) signals; and

at least one mobile station, said mobile station including;

a receiver for receiving said RF signals;

means for converting said RF signal to an intermediate frequency (IF) analog signal;

means for sampling said IF analog Signal to generate a digital IF signal, said digital signal having a data component and an interference component; and

means for canceling co-channel and cross-channel interference in said digital signal by projecting said digital signal onto a subspace orthogonal to a subspace of said interference component and multiplying this projection with said digital signal; and

means for acquisition and tracking of said projected digital signal.

68. The communication system recited in claim 67, wherein said intermediate frequency (IF) analog signal includes base band.

69. The communication system recited in claim 67, wherein said receiver comprises multiple fingers.

70. The communication system recited in claim 69, wherein said data component from one finger is treated as interference in at least one other finger of said multiple fingers.

71. The communication system recited in claim 69, wherein said data component from a first finger is treated as interference in at least a second finger of said multiple fingers.

72. The communication system recited in claim 71, wherein said data component from said first and second fingers are treated as interference in at least one other finger of said multiple fingers.