Joint space-time optimum filters (JSTOF) with at least one antenna, at least one channel, and joint filter weight and CIR estimation

• US 7,844,232 B2
• Filed: 05/25/2006
• Issued: 11/30/2010
• Est. Priority Date: 05/25/2005
• Status: Expired due to Fees

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Wu, Huan, Simmons, Sean, Kemenczy, Zoltan
• Primary Examiner(s): Nguyen; Duc
• Assistant Examiner(s): Nguyen; Hai V
• Application Number:
  US11/420,266
• Publication Number:
  US 20060268972A1
• Time in Patent Office: 1,650 Days
• Field of Search: 455/100
• US Class Current: 455/90.3
• CPC Class Codes: H04L 1/0631 Receiver arrangements
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0212 of impulse response

Abstract

A wireless communications device may include at least one virtual antenna, and a space-time filter circuit for filtering a communications signal received by the at least one virtual antenna by jointly estimating space-time filter weights and at least one channel impulse response (CIR). The wireless communications device may further include a matched filter circuit downstream from the space-time filter circuit and having a filter response that is provided by a channel impulse response estimation from the space-time filter circuit.

Claims

1. A wireless communications device comprising:

at least one virtual antenna;

a space-time filter circuit for filtering a communications signal received by said at least one virtual antenna by jointly estimating space-time filter weights and at least one channel impulse response (CIR); and

a matched filter circuit downstream from said space-time filter circuit and having a filter response that is provided by a channel impulse response estimation from said space-time filter circuit.

2. The wireless communications device of claim 1 wherein said at least one virtual antenna splits the communications signal into n signal parts.

3. The wireless communications device of claim 2 wherein said at least one virtual antenna splits the communications signal into odd and even sampled, real and imaginary n signal parts.

4. The wireless communications device of claim 2 wherein said space time filter circuit comprises a multi-channel, space-time filter circuit that filters the n signal parts by jointly estimating space-time filter weights and multi-channel impulse responses.

5. The wireless communications device of claim 4 wherein said multi-channel, space-time filter circuit comprises at least one multiplier for multiplying each signal part by a respective space-time filter weight.

6. The wireless communications device of claim 5 wherein said at least one multiplier comprises a pair thereof connected in parallel;

and wherein said multi-channel, space-time filter circuit further comprises a respective delay circuit for each signal part connected to an input of one of said pair of multipliers.

7. The wireless communications device of claim 6 wherein the communications signal comprises a plurality of symbols;

and wherein said multipliers and delay circuits each has about a one-symbol delay associated therewith.

8. The wireless communications device of claim 5 further comprising a respective summer circuit for summing outputs of the multipliers for each channel.

9. The wireless communications device of claim 1 further comprising an equalizer circuit downstream from said matched filter circuit.

10. The wireless communications device of claim 1 wherein said space-time filter circuit jointly estimates space-time filter weights and CIRs based upon Cholesky and eigenvalue decompositions.

11. The wireless communications device of claim 1 wherein said space-time filter circuit jointly estimates space-time filter weights and CIRs based upon a singular value decomposition (SVD).

12. The wireless communications device of claim 1 wherein said space-time filter circuit jointly estimates space-time filter weights and CIRs based upon QR and eigenvalue decompositions.

13. A wireless communications device comprising:

at least one virtual antenna;

a space-time filter circuit for filtering a communications signal received by said at least one virtual antenna by jointly estimating space-time filter weights and at least one channel impulse response (CTR);

a matched filter circuit downstream from said space-time filter circuit and having a filter response that is provided by a channel impulse response estimation from said space-time filter circuit; and

an alternative filter operative when an interference level is below a predetermined threshold and comprising an alternative matched filter circuit, a cross-correlation circuit, and a switch mechanism for selectively switching the communications signal into said matched filter circuit and cross-correlation circuit.

14. The wireless communications device of claim 13 wherein said at least one virtual antenna splits the communications signal into n signal parts.

15. The wireless communications device of claim 14 wherein said at least one virtual antenna splits the communications signal into odd and even sampled, real and imaginary n signal parts.

16. The wireless communications device of claim 14 wherein said space-time filter circuit comprises a multi-channel, space-time filter circuit that filters the n signal parts by jointly estimating space-time filter weights and multi-channel impulse responses.

17. The wireless communications device of claim 16 wherein said multi-channel, space-time filter circuit comprises at least one multiplier for multiplying each signal part by a respective space-time filter weight.

18. The wireless communications device of claim 17 further comprising a respective summer circuit for summing outputs of the multipliers for each channel.

19. The wireless communications device of claim 13 further comprising an equalizer circuit downstream from said matched filter circuit.

20. The wireless communications device of claim 13 wherein said space-time filter circuit jointly estimates space-time filter weights and CIRs based upon Cholesky and eigenvalue decompositions.

21. The wireless communications device of claim 13 wherein said space-time filter circuit jointly estimates space-time filter weights and CIRs based upon a singular value decomposition (SVD).

22. The wireless communications device of claim 13 wherein said space-time filter circuit jointly estimates space-time filter weights and CIRs based upon QR and eigenvalue decompositions.

23. A method of reducing co-channel interference within a wireless communications device receiver comprising:

providing at least one virtual antenna;

filtering a communications signal received by the at least one virtual antenna using a space-time filter circuit by jointly estimating space-time filter weights and at least one channel impulse response (CIR); and

generating a filter response based upon a channel impulse response estimation from the space-time filter circuit using a matched filter circuit.

24. The method of claim 23 wherein the at least one virtual antenna splits the communications signal into n signal parts.

25. The method of claim 24 wherein the at least one virtual antenna splits the communications signal into odd and even sampled, real and imaginary n signal parts.

26. The method of claim 24 wherein the space time filter circuit comprises a multi-channel, space-time filter circuit that filters the n signal parts by jointly estimating space-time filter weights and multi-channel impulse responses.

27. The method of claim 23 further comprising providing an equalizer circuit downstream from the matched filter circuit.

28. The method of claim 23 wherein jointly estimating the space-time filter weights and CIRs comprises jointly estimating the space-time filter weights and CIRs based upon Cholesky and eigenvalue decompositions.

29. The method of claim 23 wherein jointly estimating the space-time filter weights and CIRs comprises jointly estimating the space-time filter weights and CIRs based upon a singular value decomposition (SVD).

30. The method of claim 23 wherein jointly estimating the space-time filter weights and CIRs comprises jointly estimating the space-time filter weights and CIRs based upon QR and eigenvalue decompositions.

31. A mobile wireless communications device comprising:

a portable housing;

at least one virtual antenna carried by said portable housing;

a space-time filter circuit carried by said portable housing for filtering a communications signal received by said at least one virtual antenna by jointly estimating space-time filter weights and at least one channel impulse response (CIR); and

a matched filter circuit carried by said portable housing downstream from said space-time filter circuit and having a filter response that is provided by a channel impulse response estimation from said space-time filter circuit.

32. The mobile wireless communications device of claim 31 wherein said at least one virtual antenna splits the communications signal into n signal parts.

33. The mobile wireless communications device of claim 32 wherein said at least one virtual antenna splits the communications signal into odd and even sampled, real and imaginary n signal parts.

34. The mobile wireless communications device of claim 32 wherein said space time filter circuit comprises a multi-channel, space-time filter circuit that filters the n signal parts by jointly estimating space-time filter weights and multi-channel impulse responses.

35. The mobile wireless communications device of claim 31 wherein said space-time filter circuit jointly estimates space-time filter weights and CIRs based upon Cholesky and eigenvalue decompositions.

36. The mobile wireless communications device of claim 31 wherein said space-time filter circuit jointly estimates space-time filter weights and CIRs based upon a singular value decomposition (SVD).

37. The mobile wireless communications device of claim 31 wherein said space-time filter circuit jointly estimates space-time filter weights and CIRs based upon QR and eigenvalue decompositions.