Digital carrier multi-band user codes for ultra-wideband multiple access

• US 20050105588A1
• Filed: 09/29/2004
• Published: 05/19/2005
• Est. Priority Date: 09/30/2003
• Status: Active Grant

• Current Assignee: Regents of The University of Minnesota (University of Minnesota)
• Original Assignee: Regents of The University of Minnesota (University of Minnesota)
• Inventors: Giannakis, Georgios B., Yang, Liuqing
• Granted Patent: US 7,561,613 B2
• Time in Patent Office: Days
• US Class Current: 375/130
• CPC Class Codes: H04B 1/71637 Receiver aspects H04B1/7183 takes precedence
• CPC Class Codes: H04B 1/7176 Data mapping, e.g. modulation
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713

Abstract

Techniques are described for generating digital carrier multi-band user codes for a baseband ultra-wideband (UWB) signal. The digital carrier multi-band user codes comprise spreading codes that enable multiple access in a UWB system. The user codes are digital, lead to baseband operation, and provide flexibility in handling narrow band interference (NBI) within the UWB system. In one embodiment, the invention provides a method comprising generating digital carrier multi-band user codes for a baseband ultra-wideband (UWB) signal of a user in an UWB system.

Claims

1. A method comprising generating digital carrier multi-band user codes for a baseband ultra-wideband (UWB) signal of a user in an UWB system.

2. The method of claim 1, wherein the user codes comprise spreading codes that enable access for a plurality of users in the UWB system.

3. The method of claim 2, wherein the plurality of users comprises between one and thirty-two users.

4. The method of claim 1, wherein the user codes are real.

5. The method of claim 1, wherein the user codes are orthogonal to one another.

6. The method of claim 1, wherein generating digital carrier multi-band user codes comprises generating at least one digital carrier for the user.

7. The method of claim 1, wherein generating digital carrier multi-band user codes comprises generating single carrier codes.

8. The method of claim 7, wherein generating single carrier codes comprises assigning a digital carrier to the user, wherein the digital carrier occupies multiple frequency bands.

9. The method of claim 8, wherein the digital carrier comprises a shifted digital frequency that allows the digital carrier assigned to the user to occupy the same bandwidth as digital carriers assigned to other users in the UWB system.

10. The method of claim 1, wherein generating digital carrier multi-band user codes comprises generating multi-carrier codes.

11. The method of claim 10, wherein generating multi-carrier codes comprises assigning a combination of digital carriers to the user, wherein each of the digital carriers occupies multiple frequency bands.

12. The method of claim 11, further comprising assigning a different combination of digital carriers to each user in the UWB system.

13. The method of claim 11, further comprising assigning the combination of digital carriers based on a set of orthonormal sequences.

14. The method of claim 1, further comprising selecting a transmission bandwidth for the UWB signal by selecting and rejecting digital carriers.

15. The method of claim 1, further comprising selecting a transmission bandwidth for the UWB signal by rejecting digital carriers that include narrowband interference (NBI).

16. The method of claim 1, further comprising selecting a transmission bandwidth for the UWB signal by selecting a combination of digital carriers that substantially suppresses multi-user interference (MUI).

17. The method of claim 1, further comprising generating digital carrier multi-band user codes with one of a digital cosine transform and a digital sine transform.

18. The method of claim 1, further comprising generating digital carrier multi-band user codes substantially according to the following equations:

19. The method of claim 1, further comprising generating digital carrier multi-band user codes substantially according to the following equations:

20. The method of claim 1, further comprising generating periodic user codes with a period approximately equal to the number of frames in a transmitted UWB signal.

21. The method of claim 1, further comprising generating user codes that modify a pulse amplitude of the transmitted UWB signal from frame to frame.

22. The method of claim 1, further comprising applying zero padding (ZP) guards to the user codes.

23. The method of claim 1, further comprising applying cyclic prefix (CP) guards to the user codes.

24. A computer readable medium comprising instructions that when executed in an ultra-wideband (UWB) transmitter generate digital carrier multi-band user codes for a baseband UWB signal of a user in an UWB system.

25. The computer readable medium of claim 24, wherein the user codes comprise spreading codes that enable access for a plurality of users in the UWB system.

26. The computer readable medium of claim 24, wherein the user codes are real.

27. The computer readable medium of claim 24, wherein the user codes are orthogonal to one another.

28. The computer readable medium of claim 24, wherein the instructions when executed generate at least one digital carrier for the user.

29. The computer readable medium of claim 24, wherein the instructions when executed generate single carrier codes.

30. The computer readable medium of claim 29, wherein the instructions when executed assign a digital carrier to the user, wherein the digital carrier occupies multiple frequency bands.

31. The computer readable medium of claim 30, wherein the digital carrier comprises a shifted digital frequency that allows the digital carrier assigned to the user to occupy the same bandwidth as digital carriers assigned to other users in the UWB system.

32. The computer readable medium of claim 24, wherein the instructions when executed generate multi-carrier codes.

33. The computer readable medium of claim 32, wherein the instructions when executed assign a combination of digital carriers to the user, wherein each of the digital carriers occupies multiple frequency bands.

34. The computer readable medium of claim 33, further comprising instructions that when executed assign a different combination of digital carriers to each user in the UWB system.

35. The computer readable medium of claim 33, further comprising instructions that when executed assign the combination of digital carriers based on a set of orthonormal sequences.

36. The computer readable medium of claim 24, further comprising instructions that when executed select a transmission bandwidth for the UWB signal by selecting and rejecting digital carriers.

37. The computer readable medium of claim 24, further comprising instructions that when executed select a transmission bandwidth for the UWB signal by rejecting digital carriers that include narrowband interference (NBI).

38. The computer readable medium of claim 24, further comprising instructions that when executed select a transmission bandwidth for the UWB signal by selecting a combination of digital carriers that substantially suppresses multi-user interference (MUI).

39. The computer readable medium of claim 24, further comprising instructions that when executed generate digital carrier multi-band user codes with one of a digital cosine transform and a digital sine transform.

40. The computer readable medium of claim 24, further comprising instructions that when executed generate digital carrier multi-band user codes substantially according to the following equations:

41. The computer readable medium of claim 24, further comprising instructions that when executed generate digital carrier multi-band user codes substantially according to the following equations:

42. The computer readable medium of claim 24, further comprising instructions that when executed apply zero padding (ZP) guards to the user codes.

43. The computer readable medium of claim 24, further comprising instructions that when executed apply cyclic prefix (CP) guards to the user codes.

44. An ultra-wideband (UWB) transmitter comprising a user code generator to generate digital carrier multi-band user codes for a baseband UWB signal of a user in an UWB system.

45. The UWB transmitter of claim 44, wherein the user codes comprise spreading codes that enable access for a plurality of users in the UWB system.

46. The UWB transmitter of claim 44, wherein the plurality of users comprises between one and thirty-two users.

47. The UWB transmitter of claim 44, wherein the user codes are real.

48. The UWB transmitter of claim 44, wherein the user codes are orthogonal to one another.

49. The UWB transmitter of claim 44, wherein the user code generator generates at least one digital carrier for the user.

50. The UWB transmitter of claim 44, wherein the digital carrier multi-band user codes comprise single carrier codes.

51. The UWB transmitter of claim 50, wherein the user code generator assigns a digital carrier to the user, wherein the digital carrier occupies multiple frequency bands.

52. The UWB transmitter of claim 51, wherein the digital carrier comprises a shifted digital frequency that allows the digital carrier assigned to the user to occupy the same bandwidth as digital carriers assigned to other users in the UWB system.

53. The UWB transmitter of claim 44, wherein the digital carrier multi-band user codes comprise multi-carrier codes.

54. The UWB transmitter of claim 53, wherein the user code generator assigns a combination of digital carriers to the user, wherein each of the digital carriers occupies multiple frequency bands.

55. The UWB transmitter of claim 54, wherein the user code generator assigns a different combination of digital carriers to each user in the UWB system.

56. The UWB transmitter of claim 54, wherein the user code generator assigns the combination of digital carriers based on a set of orthonormal sequences.

57. The UWB transmitter of claim 44, wherein the user code generator selects and rejects digital carriers to select a transmission bandwidth for the UWB signal.

58. The UWB transmitter of claim 44, wherein the user code generator rejects digital carriers that include narrowband interference (NBI) to select a transmission bandwidth for the UWB signal.

59. The UWB transmitter of claim 44, wherein the user code generator selects a combination of digital carriers that substantially suppresses multi-user interference (MUI) to select a transmission bandwidth for the UWB signal.

60. The UWB transmitter of claim 44, wherein the user code generator includes one of a digital cosine transform and a digital sine transform to generate digital carrier multi-band user codes.

61. The UWB transmitter of claim 44, wherein the user code generator generates digital carrier multi-band user codes substantially according to the following equations:

62. The UWB transmitter of claim 44, wherein the user code generator generates digital carrier multi-band user codes substantially according to the following equations:

63. The UWB transmitter of claim 44, wherein the user codes are periodic with a period approximately equal to the number of frames in the UWB signal.

64. The UWB transmitter of claim 44, wherein the user codes modify a pulse amplitude of the UWB signal from frame to frame.

65. The UWB transmitter of claim 44, wherein the user code generator applies zero padding (ZP) guards to the user codes.

66. The UWB transmitter of claim 44, wherein the user code generator applies cyclic prefix (CP) guards to the user codes.