Blind signal separation using correlated antenna elements

• US 7,414,579 B2
• Filed: 09/22/2005
• Issued: 08/19/2008
• 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: Kostanic, Ivica, Goldberg, Steven J., Gorsuch, Thomas E., Hoffmann, John E.
• Primary Examiner(s): Tarcza, Thomas H
• Assistant Examiner(s): Mull, Fred H.
• Application Number:
  US11/232,500
• Publication Number:
  US 20060069529A1
• Time in Patent Office: 1,062 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 7/08 at the receiving station

Abstract

A communications device for separating source signals provided by M signal sources includes an antenna array comprising N correlated antenna elements for receiving at least N different summations of the M source signals, with N and M being greater than 1. A receiver is connected to the antenna array for receiving the at least N different summations of the M source signals. A blind signal separation processor is connected to the receiver for forming a mixing matrix comprising up to 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 to at least N.

Claims

1. A communications device for separating source signals provided by M signal sources, the communications device having an operating frequency and comprising:

an antenna array comprising N correlated antenna elements for receiving at least N different summations of the M source signals, with N and M being greater than 1, said N correlated antenna elements being spaced apart so that a distance D between any two immediately adjacent antenna elements is less than a wavelength λ

of the operating frequency of the communications device, where 0<

D<

λ

, said N correlated antenna elements comprising at least one active antenna element and up to N−

1 passive antenna elements so that said antenna array forms a switched beam antenna;

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

M.

4. 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.

5. 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.

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

7. 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).

8. 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).

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

10. A method for operating a communications device for separating source signals provided by M signal sources, the communications device having an operating frequency and 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 antenna array comprising N correlated antenna elements, with N and M being greater than 1, the N correlated antenna elements being spaced apart so that a distance D between any two immediately adjacent antenna elements is less than a wavelength λ

of the operating frequency of the communications device, where 0<

D<

λ

, the N correlated antenna elements comprising at least one active antenna element and up to N−

1 passive antenna elements so that the antenna array forms a switched beam antenna;

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

separating desired source signals from the mixing matrix.

11. A method according to claim 10 wherein N=M.

12. A method according to claim 10 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.

13. A method according to claim 10 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.

14. A method according to claim 10 wherein each summation of the M source signals is linear.

15. A method according to claim 10 wherein the blind signal separation processor separates the desired source signals from the mixing matrix based on principal component analysis (PCA).

16. A method according to claim 10 wherein the blind signal separation processor separates the desired source signals from the mixing matrix based on independent component analysis (ICA).

17. A method according to claim 10 wherein the blind signal separation processor separates the desired source signals from the mixing matrix based on singular value decomposition (SVD).