Receiver hardware reduction for spatially independent signals and associated methods

• US 7,860,182 B2
• Filed: 12/30/2005
• Issued: 12/28/2010
• 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: Gorsuch, Thomas E., Hoffmann, John E.
• Primary Examiner(s): Odom, Curtis B
• Application Number:
  US11/323,944
• Publication Number:
  US 20060153319A1
• Time in Patent Office: 1,824 Days
• Field of Search: 375/260, 375/267, 375/299, 375/347, 370/296
• US Class Current: 375/267
• CPC Class Codes: H04B 7/08 at the receiving station
• CPC Class Codes: H04B 7/0805 with single receiver and antenna switching H04B7/0822 takes precedence
• CPC Class Codes: H04B 7/0871 using different reception schemes, at least one of them being a diversity reception scheme
• CPC Class Codes: H04B 7/0874 using subgroups of receive antennas

Abstract

A communications device includes an antenna array comprising antenna elements for receiving at least N spatially independent signals, and a receiver coupled to the antenna array. The receiver includes an analog receiver circuit for receiving the N spatially independent signals, and has a bandwidth of at least N times an information bandwidth of the spatially independent signals. The receiver further includes a digital receiver circuit coupled to the analog receiver circuit, and samples the N spatially independent signals at a rate of at least N times a Nyquist rate which would have been required if a single antenna element had been used to receive the signals. A processor is coupled to the digital receiver circuit for demultiplexing the sampled N spatially independent signals.

Claims

1. A communications device comprising:

an antenna array comprising a plurality of antenna elements for receiving at least N spatially independent signals;

a receiver coupled to said antenna array and comprising

an analog receiver circuit for receiving the N spatially independent signals, and having a bandwidth of at least N times an information bandwidth of the spatially independent signals, and

a digital receiver circuit coupled to said analog receiver circuit, and sampling the N spatially independent signals at a rate of at least N times a Nyquist rate which would have been required if a single antenna element had been used to receive the signals, and comprising an analog-to-digital converter for converting the N spatially independent signals to N spatially independent digital signals;

a controller coupled to said antenna array and comprising

a switching circuit coupled to said antenna array for switching between said plurality of antenna elements for sampling the N spatially independent signals by said antenna array, and

a timing circuit coupled to said switching circuit for coordinating sampling of the N spatially independent signals by said antenna array based on sample timing of the N spatially independent digital signals by said analog-to-digital converter; and

a processor coupled to said digital receiver circuit for demultiplexing the sampled N spatially independent digital signals, and coupled to said timing circuit for providing the sample timing of the N spatially independent digital signals by said analog-to-digital converter.

2. A communications device according to claim 1 wherein said digital receiver circuit comprises a single analog-to-digital converter.

3. A communications device according to claim 1 wherein said processor demodulates in parallel the N spatially independent signals after having been demultiplexed, with the N demodulated signals then being combined for signal processing.

4. A communications device according to claim 1 wherein said processor reconstructs the N independently transmitted signals.

5. A communications device according to claim 1 wherein said plurality of antenna elements comprise N uncorrelated antenna elements.

6. A communications device according to claim 1 wherein said plurality of antenna elements comprise N correlated antenna elements.

7. A communications device according to claim 6 wherein said N correlated antenna elements comprise N active antenna elements so that said antenna array forms a phased array.

8. A communications device according to claim 6 wherein said N correlated antenna elements comprise at least one active antenna element, and up to N−

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

9. A communications device according to claim 3 wherein the signal processing is based upon at least one of a knowledge based signal extraction process and a blind signal separation process.

10. A communications device according to claim 9 wherein the blind signal separation process is based on at least one of principal component analysis (PCA), independent component analysis (ICA) and single value decomposition (SVD).

11. A communications device according to claim 9 wherein the knowledge based signal separation process is based on at least one of a zero forcing (2F) process and a minimum mean squared estimation (MMSE) process.

12. A communications device according to claim 1 wherein the N spatially independent signals correspond to a single transmitted signal.

13. A communications device according to claim 1 wherein the N spatially independent signals correspond to N independently transmitted signals from a MIMO transmitter;

and wherein said processor reconstructs the N independently transmitted signals.

14. A communications device according to claim 1 further comprising:

a transmitter; and

a switch coupled between said antenna array, said transmitter and said receiver so that the communications device operates in a half-duplex mode.

15. A communications device according to claim 1 further comprising:

a transmitter; and

at least one additional antenna element dedicated to said transmitter so that the communications device operates in a full-duplex mode.

16. A method for operating a communications device comprising an antenna array comprising a plurality of antenna elements, an analog receiver circuit coupled to the antenna array, a digital receiver circuit coupled to the analog receiver circuit comprising an analog-to-digital converter, a processor coupled to the digital receiver circuit, and a controller coupled to the antenna array and comprising a switching circuit coupled to the antenna array and a timing circuit coupled to the processor, the method comprising:

receiving at least N spatially independent signals by the antenna array;

providing the N spatially independent signals to analog receiver circuit, the analog receiver circuit having a bandwidth of at least N times an information bandwidth of the spatially independent signals;

sampling in the digital receiver circuit the N spatially independent signals at a rate of at least N times a Nyquist rate which would have been required if a single antenna element had been used to receive the signals;

converting in the analog-to-digital converter the sampled N spatially independent signals to N spatially independent digital signals;

operating the switch controller for

causing the switching circuit coupled to the antenna array to switch the plurality of antenna elements for sampling the N spatially independent signals by the antenna array based on operation of the switching circuit, and

causing the timing circuit coupled to the switching circuit to sample the N spatially independent signals by the antenna array based on a sample timing of the N spatially independent digital signals by the analog-to-digital converter; and

demultiplexing the sampled N spatially independent digital signals in the processor, and providing from the processor to the timing circuit the sample timing of the N spatially independent digital signals by the analog-to-digital converter.

17. A method according to claim 16 wherein the digital receiver circuit comprises a single analog-to-digital converter.

18. A method according to claim 16 wherein the processor demodulates in parallel the N spatially independent signals after having been demultiplexed, with the N demodulated signals then being combined for signal processing.

19. A method according to claim 16 wherein the processor reconstructs the N independently transmitted signals.

20. A method according to claim 16 wherein the plurality of antenna elements comprise N uncorrelated antenna elements.

21. A method according to claim 16 wherein the plurality of antenna elements comprise N correlated antenna elements.

22. A method according to claim 21 wherein the N correlated antenna elements comprise N active antenna elements so that the antenna array forms a phased array.

23. A method according to claim 21 wherein the N correlated antenna elements comprise at least one active antenna element, and up to N−

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

24. A method according to claim 18 wherein the signal processing is based upon at least one of a knowledge based signal extraction process and a blind signal separation process.

25. A method according to claim 16 wherein the N spatially independent signals correspond to a single transmitted signal.

26. A method according to claim 16 wherein the N spatially independent signals correspond to N independently transmitted signals from a MIMO transmitter;

and wherein the processor reconstructs the N independently transmitted signals.

27. A method according to claim 16 wherein the communications device further comprises a transmitter, and a switch coupled between the antenna array, the transmitter and the receiver so that the communications device operates in a half-duplex mode.

28. A method according to claim 16 wherein the communications device further comprises a transmitter, and at least one additional antenna element dedicated to the transmitter so that the communications device operates in a full-duplex mode.