Blind signal separation using a combination of correlated and uncorrelated antenna elements

• US 7,113,129 B2
• Filed: 09/22/2005
• Issued: 09/26/2006
• Est. Priority Date: 09/23/2004
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Goldberg, Steven J.
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): Mull, Fred H.
• Application Number:
  US11/233,300
• Publication Number:
  US 20060066481A1
• Time in Patent Office: 369 Days
• Field of Search: 342/373, 342377-378, 342/380, 342382-383, 702190-197, 702/FOR.164
• US Class Current: 342/378
• CPC Class Codes: H04B 1/7115 Constructive combining of multi-path signals, i.e. RAKE receivers
• CPC Class Codes: H04B 7/08 at the receiving station
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity

Abstract

A communications device for separating source signals provided by M signal sources includes an antenna array comprising N antenna elements for receiving at least N different summations of the M source signals, with N and M being greater than 1. The N antenna elements include at least one antenna element for receiving at least one of the N different summations of the M source signals, and at least two correlated antenna elements for receiving at least two of the N different summations of the M source signals. The at least two correlated antenna elements are uncorrelated with the at least one antenna element. A receiver is connected to the antenna array. A blind signal separation processor is connected to the receiver for forming a mixing matrix comprising the at least N different summations of the M source signals, and for separating desired source signals from the mixing matrix. The mixing matrix has a rank equal up to at least N.

Claims

1. A communications device for separating source signals provided by M signal sources, the communications device comprising:

an antenna array comprising N antenna elements for receiving at least N different summations of the M source signals, with N and M being greater than 1, said N antenna elements comprising

at least one antenna element for receiving at least one of the N different summations of the M source signals, and

at least two correlated antenna elements for receiving at least two of the N different summations of the M source signals;

said at least two correlated antenna elements being uncorrelated with said at least one antenna element;

a receiver connected to said antenna array for receiving the at least N different summations of the M source signals; and

a blind signal separation processor connected to said receiver for forming a mixing matrix comprising the at least N different summations of the M source signals, the mixing matrix having a rank equal up to at least N, said blind signal separation processor for separating desired source signals from the mixing matrix.

2. A communications device according to claim 1 wherein N=M.

3. A communications device according to claim 1 wherein the rank of the mixing matrix is K, where K<

N, and said blind signal separation processor separating K of the M source signals from the mixing matrix.

4. A communications device according to claim 1 wherein N>

M.

5. A communications device according to claim 1 wherein said at least two correlated antenna elements have different polarizations.

6. A communications device according to claim 5 wherein the different polarizations are orthogonal to one another.

7. A communications device according to claim 1 wherein said at least two antenna elements comprises 3 antenna elements that are also correlated and have different polarizations so that tri-polarization is supported for receiving 3 different summations of the M source signals.

8. A communications device according to claim 7 wherein said at least two correlated antenna elements have different polarizations.

9. A communications device according to claim 1 wherein said at least one antenna element also comprises at least two correlated antenna elements for receiving at least two of the N different summations of the M source signals.

10. A communications device according to claim 1 wherein said at least two correlated antenna elements comprise at least two active antenna elements for forming a phased array.

11. A communications device according to claim 1 wherein said at least two correlated antenna elements comprise at least one active antenna element and at least one passive antenna element for forming a switched beam antenna.

12. A communications device according to claim 1 wherein said antenna array forms at least N antenna beams for receiving the at least N different summations of the M source signals, each antenna beam having 3 db points down from a maximum gain point thereof providing for signal rejection in at least one direction of an approaching signal.

13. A communications device according to claim 1 wherein said antenna array forms at least one antenna pattern for receiving at least one of the N different summations of the M source signals, the at least one antenna pattern having substantially no 3 db points down from a maximum gain point thereof resulting in no signal rejection in any direction of an approaching signal.

14. A communications device according to claim 1 wherein each summation of the M source signals is linear.

15. A communications device according to claim 1 wherein said blind signal separation processor separates the desired source signals from the mixing matrix based on principal component analysis (PCA).

16. A communications device according to claim 1 wherein said blind signal separation processor separates the desired source signals from the mixing matrix based on independent component analysis (ICA).

17. A communications device according to claim 1 wherein said blind signal separation processor separates the desired source signals from the mixing matrix based on single value decomposition (SVD).

18. A method for operating a communications device for separating source signals provided by M signal sources, the communications device comprising an antenna array, a receiver connected to the antenna array, and a blind signal separation processor connected to the receiver, the method comprising:

receiving at the antenna array at least N different summations of the M source signals, the N antenna elements comprising

at least one antenna element for receiving at least one of the N different summations of the M source signals, and

at least two correlated antenna elements for receiving at least two of the N different summations of the M source signals;

the at least two correlated antenna elements being uncorrelated with the at least one antenna element;

providing the at least N different summations of the M source signals to the receiver; and

processing by the blind signal separation processor the at least N different summations of the M source signals received by the receiver, the processing comprising

forming a mixing matrix comprising the at least N different summations of the M source signals, the mixing matrix having a rank equal up to at least N, and

separating desired source signals from the mixing matrix.

19. A method according to claim 18 wherein N=M.

20. A method according to claim 18 wherein the at least two correlated antenna elements have different polarizations.

21. A method according to claim 20 wherein the different polarizations are orthogonal to one another.

22. A method according to claim 18 wherein the at least two antenna elements comprises 3 antenna elements that are also correlated and have different polarizations so that tri-polarization is supported for receiving 3 different summations of the M source signals.

23. A method according to claim 22 wherein the at least two correlated antenna elements have different polarizations.

24. A method according to claim 18 wherein the at least one antenna element also comprises at least two correlated antenna elements for receiving at least two of the N different summations of the M source signals.

25. A method according to claim 18 wherein the at least two correlated antenna elements comprise at least two active antenna elements for forming a phased array.

26. A method according to claim 18 wherein the at least two correlated antenna elements comprise an active antenna element and at least one passive antenna element for forming a switched beam antenna.

27. A method according to claim 18 wherein the antenna array forms at least N antenna beams for receiving the at least N different summations of the M source signals, each antenna beam having 3 db points down from a maximum gain point thereof providing for signal rejection in at least one direction of an approaching signal.

28. A method according to claim 18 wherein the antenna array forms at least one antenna pattern for receiving at least one of the N different summations of the M source signals, the at least one antenna pattern having substantially no 3 db points down from a maximum gain point thereof resulting in no signal rejection in any direction of an approaching signal.

29. A method according to claim 18 wherein each summation of the M source signals is linear.

30. A method according to claim 18 wherein the blind signal separation processor separates the desired source signals from the mixing matrix based on principal component analysis (PCA).

31. A method according to claim 18 wherein the blind signal separation processor separates the desired source signals from the mixing matrix based on independent component analysis (ICA).

32. A method according to claim 18 wherein the blind signal separation processor separates the desired source signals from the mixing matrix based on single value decomposition (SVD).