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

• US 7,561,613 B2
• Filed: 09/29/2004
• Issued: 07/14/2009
• 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
• Primary Examiner(s): Payne; David C
• Assistant Examiner(s): Wong; Linda
• Application Number:
  US10/953,493
• Publication Number:
  US 20050105588A1
• Time in Patent Office: 1,749 Days
• Field of Search: 375/135, 375/136, 375/137, 375/130, 375/240.11, 375/295, 370/208, 370/329, 370/330
• US Class Current: 375/134
• 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, in a transmitter device, a set of two or more digital frequencies, wherein each digital frequency corresponds to a subcarrier within an ultra-wideband (UWB) system;

processing, in the transmitter device, the digital frequencies with a digital transform function to generate a plurality of digital carriers, wherein each of the digital carriers occupies multiple frequency bands; and

assigning, in the transmitter device, different combinations of the digital carriers to the users within the UWB system to generate digital carrier multi-band user codes substantially according to the following equations;

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 orthogonal to one another.

5. The method of claim 1, wherein assigning the different combinations of the digital carriers to the users comprises assigning at least one digital carrier to each user.

6. The method of claim 1, wherein the digital carrier multi-band user codes are multi-carrier codes.

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

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

9. 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).

10. The method of claim 1, wherein processing the digital frequencies comprises processing the digital frequencies with one of a digital cosine transform and a digital sine transform

11. 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.

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

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

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

15. The method of claim 1, wherein assigning the different combinations of the digital carriers to the users comprises assigning a different combination of digital carriers to each user in the UWB system.

16. The method of claim 1, wherein assigning the different combinations of the digital carriers to the users comprises assigning combinations of the digital carriers based on a set of orthonormal sequences.

17. A method comprising:

generating, in a transmitter device, a set of two or more digital frequencies, wherein each digital frequency corresponds to a user within an ultra-wideband (UWB) system;

processing, in the transmitter device, the digital frequencies with a digital transform function to generate a plurality of digital carriers, wherein each of the digital carriers occupies multiple frequency bands; and

assigning, in the transmitter device, the digital carriers to the users within the UWB system to generate digital carrier multi-band user codes substantially according to the following equations;

18. The method of claim 17, wherein the digital carrier multi-band user codes are single carrier codes.

19. The method of claim 17, wherein each of the digital carriers comprises a shifted digital frequency that allow a digital carrier assigned to the user to occupy the same bandwidth as digital carriers assigned to other user in the UWB system.

20. The method of claim 17, wherein assigning the digital carriers to the users comprises assigning a single digital carrier to each user.

21. A computer readable medium comprising instructions stored therein that, when executed in an ultra wideband (UWB) transmitter, cause the UWB transmitter to:

generate a set of two or more digital frequencies, wherein each digital frequency corresponds to a user within an ultra-wideband (UWB) system;

process the digital frequencies with a digital transform function to generate a plurality of digital carriers, wherein each of the digital carriers occupies multiple frequency bands; and

assign the digital carriers to the users within the UWB system to generate digital carrier multi-band user codes substantially according to the following equations;

22. The computer readable medium of claim 21, wherein the digital carrier multi-band user codes are single carrier codes.

23. The computer readable medium of claim 21, wherein each of the digital carriers comprises a shifted digital frequency that allows a digital carrier assigned to the user to occupy the same bandwidth as digital carriers assigned to other users in the UWB system.

24. The computer readable medium of claim 21, wherein the instructions that cause the UWB transmitter to assign the digital carriers to the users comprise instructions that, when executed, cause the UWB transmitter to assign a single digital carrier to each user.

25. A computer readable medium comprising instructions stored therein that, when executed in an ultra wideband (UWB) transmitter, cause the UWB transmitter to:

generate a set of two or more digital frequencies, wherein each digital frequency corresponds to a subcarrier within an ultra-wideband (UWB) system;

process the digital frequencies with a digital transform function to generate a plurality of digital carriers, wherein each of the digital carriers occupies multiple frequency bands; and

assign different combinations of the digital carriers to the users within the UWB system to generate digital carrier multi-band user codes substantially according to the following equations;

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

27. The computer readable medium of claim 25, wherein the user codes are orthogonal to one another.

28. The computer readable medium of claim 25, wherein the instructions that cause the UWB transmitter to assign the different combinations of the digital carriers comprise instructions that, when executed, cause the UWB transmitter to assign at least one digital carrier to each user.

29. The computer readable medium of claim 25, wherein the digital carrier multi-band user codes are multi-carrier codes.

30. The computer readable medium of claim 25, further comprising instructions stored therein that, when executed, cause the UWB transmitter to select a transmission bandwidth for the UWB signal by selecting and rejecting digital carriers.

31. The computer readable medium of claim 25, further comprising instructions stored therein that, when executed, cause the UWB transmitter to select a transmission bandwidth for the UWB signal by rejecting digital carriers that include narrowband interference (NBI).

32. The computer readable medium of claim 25, further comprising instructions stored therein that, when executed, cause the UWB transmitter to select a transmission bandwidth for the UWB signal by selecting a combination of digital carriers that substantially suppresses multi-user interference (MUI).

33. The computer readable medium of claim 25, further comprising instructions stored therein that, when executed, cause the UWB transmitter to generate digital carrier multi-band user codes with one of a digital cosine transform and a digital sine transform.

34. The computer readable medium of claim 25, further comprising instructions stored therein that, when executed, cause the UWB transmitter to apply zero padding (ZP) guards to the user codes.

35. The computer readable medium of claim 25, further comprising instructions stored therein that, when executed, cause the UWB transmitter to apply cyclic prefix (CP) guards to the user codes.

36. The computer readable medium of claim 25, wherein the instructions that cause the UWB transmitter to assign the different combinations of the digital carriers to the users comprise instructions that, when executed, cause the UWB transmitter to assign a different combination of digital carriers to each user in the UWB system.

37. The computer readable medium of claim 25, wherein the instructions that cause the UWB transmitter to assign the different combinations of the digital carriers to the users comprise instructions that, when executed, cause the UWB transmitter to assign combinations of digital carriers based on a set of orthonormal sequences.

38. An ultra-wideband (UWB) transmitter device comprising a user code generator that generates a set of two or more digital frequencies, wherein each digital frequency corresponds to a user within an ultra-wideband (UWB) system;

processes the digital frequencies with a digital transform function to generate a plurality of digital caters, wherein each of the digital carriers occupies multiple frequency bands; and

assigns the digital carriers to the users within the UWB system to generate digital carrier multi-band user codes substantially according to the following equations;

39. The UWB transmitter device of claim 38, wherein the digital carrier multi-band user codes are single carrier codes.

40. The UWB transmitter device of claim 38, wherein the user code generator assigns a single digital carrier to each user.

46. The UWB transmitter device of claim 38, wherein each of the digitals carrier comprises a shifted digital frequency that allows a digital carrier assigned to the user to occupy the same bandwidth as digital carriers assigned to other users in the UWB system.

41. An ultra-wideband (UWB) transmitter device comprising a user code generator that generates a set of two or more digital frequencies, wherein each digital frequency corresponds to a user within an ultra-wideband (UWB) system, processes the digital frequencies with a digital transform function to generate a plurality of digital carriers, wherein each of the digital carriers occupies multiple frequency bands;

and assigns different combinations of the digital carriers to the users within the UWB system to generate digital carrier multi-band user codes substantially according to the following equations;

42. The UWB transmitter device of claim 41, wherein the user codes comprise spreading codes that enable access for a plurality of users in the UWB system.

43. The UWB transmitter device of claim 41, wherein the plurality of users comprises between one and thirty-two users.

44. The UWB transmitter device of claim 41, wherein the user codes are orthogonal to one another.

45. The UWB transmitter device of claim 41, wherein the user code generator assigns at least one digital carrier to each user.

47. The UWB transmitter device of claim 41, wherein the digital carrier multi-band user codes are multi-carrier codes.

48. The UWB transmitter device of claim 41, wherein the user code generator selects and rejects digital carriers to select a transmission bandwidth for the UWB signal.

49. The UWB transmitter device of claim 41, wherein the user code generator rejects digital carriers that include narrowband interference (NBI) to select a transmission bandwidth for the UWB signal.

50. The UWB transmitter device of claim 41, 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.

51. The UWB transmitter device of claim 41, 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.

52. The UWB transmitter device of claim 41, wherein the user codes are periodic with a period approximately equal to the number of frames in the UWB signal.

53. The UWB transmitter device of claim 41, wherein the user codes modify a pulse amplitude of the UWB signal from frame to frame.

54. The UWB transmitter device of claim 41, wherein the user code generator applies zero padding (ZP) guards to the user codes.

55. The UWB transmitter device of claim 41, wherein the user code generator applies cyclic prefix (CP) guards to the user codes.

56. The UWB transmitter device of claim 41, wherein the user code generator assigns a different combination of digital carriers to each user in the UWB system.

57. The UWB transmitter device of claim 41, wherein the user code generator assigns combinations of digital carriers based on a set of orthonormal sequences.