Multiple antenna multicarrier communication system and method with reduced mobile-station processing

• US 20060114816A1
• Filed: 11/30/2004
• Published: 06/01/2006
• Est. Priority Date: 11/30/2004
• Status: Active Grant

• Current Assignee: Tahoe Research Limited (f/k/a Learndale Limited) (Vector Capital Corporation)
• Original Assignee: Intel Corporation
• Inventors: Pudeyev, Andrey V., Maltsev, Alexander A., Davydov, Alexei V., Sandhu, Sumeet, Sadri, Ali S., Tiraspolsky, Sergey A.
• Granted Patent: US 7,649,861 B2
• Time in Patent Office: Days
• US Class Current: 370/210
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0613 using simultaneous transmission H04B7/0686 takes precedence
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 2025/03426 transmission using multiple-input and multiple-output channels
• CPC Class Codes: H04L 2025/03802 Signalling on the reverse channel
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01

Abstract

In a multiple-input multiple-output (MIMO) multicarrier communication system, a mobile station sends a quantized time-domain representation of the channel transfer function to a base station for use by the base station in generating beamforming coefficients for use in subsequent transmissions to the mobile station. In some embodiments, the quantized time-domain representation of the channel transfer function may be generated from selected most significant rays of an initial estimated sampled channel impulse response. Other embodiments may be described and claimed.

Claims

1. A method comprising sending a quantized time-domain representation of a channel transfer function from a mobile station to a base station for use by the base station in generating beamforming coefficients for use in subsequent transmissions to the mobile station.

2. The method of claim 1 further comprising estimating a sampled channel impulse response for channel paths between the mobile station and the base station,

wherein the estimated sampled channel impulse response is represented by a plurality of rays for each channel path, and

wherein each ray is associated with a delay and has an amplitude component and a phase component.

3. The method of claim 2 further comprising:

selecting, for each channel path, most significant rays from the estimated sampled channel impulse response;

calculating a time-domain representation of the channel transfer function for the selected rays; and

quantizing the time-domain representation to generate the quantized representation of the channel transfer function for sending to the base station.

4. The method of claim 3 wherein quantizing comprises representing each of the associated delay, the amplitude component, and the phase component of the selected rays of the estimated sampled channel impulse response by a predetermined number of bits.

5. The method of claim 3 wherein each of the channel paths is defined by a combination of transmit and receive antenna pairs, and

wherein a communication channel between the mobile station and the base station comprises the channel paths therebetween.

6. The method of claim 5 wherein the base station and the mobile station comprise at least part of a multiple-input multiple-output multicarrier communication system,

wherein the base station includes at least two transmit antennas and the mobile station includes at least two receive antennas defining the channel paths, and

wherein the selecting, calculating, and quantizing are performed by the mobile station for each channel path to generate the quantized time-domain representation of the channel transfer function for the communication channel.

7. The method of claim 3 further comprising performing an inverse Fourier transformation on an initial channel transfer function estimate to generate the sampled channel impulse response.

8. The method of claim 7 further comprises generating the initial channel transfer function estimate from orthogonal training symbols transmitted by the base station on different transmit antennas.

9. The method of claim 3 wherein after receipt of the quantized time-domain representation of the channel transfer function from the mobile station, the base station performs a Fourier transformation on the quantized time-domain representation of the channel transfer function to generate a channel transfer function matrix for each subcarrier.

10. The method of claim 9 wherein the base station further performs singular value decompositions on the channel transfer function matrices to generate the beamforming coefficients for use by the base station in generating signals for a plurality of transmit antennas.

11. A multicarrier mobile station comprising:

circuitry to generate a quantized time-domain representation of a channel transfer function; and

circuitry to send the quantized time-domain representation of a channel transfer function to a base station for use by the base station in generating beamforming coefficients for use in subsequent transmissions to the mobile station.

12. The mobile station of claim 11 further comprising circuitry to generate a sampled channel impulse response for channel paths between the mobile station and the base station,

wherein the sampled channel impulse response is represented by a plurality of rays for each channel path, and

wherein each ray is associated with a delay and has an amplitude component and a phase component.

13. The mobile station of claim 12 comprising:

a ray selector to select, for each channel path, most significant rays from the sampled channel impulse response and to calculate a time-domain representation of the channel transfer function for the selected rays; and

a quantizer to quantize the time-domain representation to generate the quantized representation of the channel transfer function for sending to the base station.

14. The mobile station of claim 13 wherein the quantizer is to represent each of the associated delay, the amplitude component, and the phase component of the selected rays of the sampled channel impulse response by a predetermined number of bits.

15. The mobile station of claim 13 wherein each of the channel paths is defined by a combination of transmit and receive antenna pairs,

wherein a communication channel between the mobile station and the base station comprises the channel paths therebetween.

16. The mobile station of claim 15 wherein the base station and the mobile station comprise at least part of a multiple-input multiple-output multicarrier communication system,

wherein the base station includes at least two transmit antennas and the mobile station includes at least two receive antennas defining the channel paths, and

wherein the ray selector selects significant rays and the quantizer quantizes time-domain representation of the channel transfer function for each channel path to generate the quantized time-domain representation of the channel transfer function for the communication channel.

17. The mobile station of claim 13 comprising:

a channel estimator to generate an initial channel estimate; and

inverse Fourier transform circuitry to perform inverse Fourier transformations on the initial channel estimate to generate the sampled channel impulse response.

18. The mobile station of claim 17 wherein the channel estimator generates the initial channel estimate from orthogonal training symbols transmitted by the base station on different transmit antennas.

19. The mobile station of claim 13 wherein after receipt of the quantized time-domain representation of the channel transfer function from the mobile station, the base station is to perform a Fourier transformation on the quantized time-domain representation of the channel transfer function to generate a channel transfer function matrix for each subcarrier.

20. The mobile station of claim 19 wherein the base station is to further perform singular value decompositions on the channel transfer function matrices to generate the beamforming coefficients for use by the base station in generating signals for a plurality of transmit antennas.

21. A method performed by a base station comprising receiving a quantized time-domain representation of a channel transfer function from a mobile station for use by the base station in generating beamforming coefficients for use in subsequent transmissions to the mobile station.

22. The method of claim 21 wherein after receipt of the quantized time-domain representation of the channel transfer function from the mobile station, the method further comprises:

performing an inverse Fourier transformation on the quantized time-domain representation of the channel transfer function to generate a channel transfer function matrix for each subcarrier of a multicarrier communication channel.

23. The method of claim 22 further comprising performing singular value decompositions on the channel transfer function matrices to generate the beamforming coefficients.

24. The method of claim 21 wherein a sampled channel impulse response is generated for channel paths between the mobile station and the base station,

wherein the sampled channel impulse response is represented by a plurality of rays for each channel path, and

wherein each ray is associated with a delay and has an amplitude component and a phase component.

25. The method of claim 24 wherein for each channel path, most significant rays are selected from the sampled channel impulse response, a time-domain representation of the channel transfer function is calculated for the selected rays, and the time-domain representation is quantized to generate the quantized representation of the channel transfer function for receipt by the base station.

26. The method of claim 24 wherein quantizing comprises representing each of the associated delay, the amplitude component, and the phase component of the selected rays of the sampled channel impulse response by a predetermined number of bits.

27. The method of claim 24 wherein each of the channel paths is defined by a combination of transmit and receive antenna pairs, and

wherein a communication channel between the mobile station and the base station comprises the channel paths therebetween.

28. The method of claim 27 wherein the base station and the mobile station comprise at least part of a multiple-input multiple-output multicarrier communication system,

wherein the base station includes at least two transmit antennas and the mobile station includes at least two receive antennas defining the channel paths, and

wherein the mobile station selects, calculates and quantizes for each channel path to generate the quantized time-domain representation of the channel transfer function for the communication channel.

29. The method of claim 24 wherein the mobile station performs an inverse Fourier transformation on an initial channel transfer function estimate to generate the sampled channel impulse response.

30. The method of claim 29 wherein the mobile station generates the initial channel estimate from orthogonal training symbols transmitted by the base station on different transmit antennas.

31. A base station comprising:

circuitry to receive a quantized time-domain representation of a channel transfer function from a mobile station; and

circuitry to generate beamforming coefficients for use in subsequent transmissions to the mobile station.

32. The base station of claim 31 comprising inverse Fourier transform circuitry to perform an inverse Fourier transformation on the quantized time-domain representation of the channel transfer function to generate a channel transfer function matrix for each subcarrier of a multicarrier communication channel.

33. The base station of claim 32 comprising:

singular value decomposition circuitry to perform singular value decompositions on the channel transfer function matrices to generate the beamforming coefficients; and

beamformers to apply the beamforming coefficients to frequency-domain signals.

34. The base station of claim 31 wherein a sampled channel impulse response is generated by the mobile station for channel paths between the mobile station and the base station,

wherein the sampled channel impulse response is represented by a plurality of rays for each channel path, and

wherein each ray is associated with a delay and has an amplitude component and a phase component.

35. The base station of claim 34 wherein for each channel path, most significant rays are selected by the mobile station from the sampled channel impulse response, a time-domain representation of the channel transfer function is calculated for the selected rays, and the time-domain representation is quantized to generate the quantized representation of the channel transfer function for receipt by the base station.

36. The base station of claim 34 wherein the mobile station represents each of the associated delay, the amplitude component, and the phase component of the selected rays of the sampled channel impulse response by a predetermined number of bits.

37. The base station of claim 34 wherein each of the channel paths between the mobile station and the base station are defined by a combination of transmit and receive antenna pairs, and

wherein a communication channel between the mobile station and the base station comprise the channel paths therebetween.

38. The base station of claim 37 wherein the base station and the mobile station comprise at least part of a multiple-input multiple-output multicarrier communication system,

wherein the base station includes at least two transmit antennas and the mobile station includes at least two receive antennas defining the channel paths, and

wherein the mobile station selects, calculates and quantizes for each channel path to generate the quantized time-domain representation of the channel transfer function for the communication channel.

39. The base station of claim 34 wherein the mobile station performs an inverse Fourier transformation on an initial channel transfer function estimate to generate the sampled channel impulse response.

40. The base station of claim 39 wherein the mobile station generates the initial channel estimate from orthogonal training symbols transmitted by the base station on different transmit antennas.

41. A multicarrier communication system comprising:

a base station; and

a mobile station to generate a quantized time-domain representation of a channel transfer function and to send the quantized time-domain representation of a channel transfer function to a base station for use by the base station in generating beamforming coefficients for use in subsequent transmissions to the mobile station,

wherein the base station is to perform an inverse Fourier transformation on the quantized time-domain representation of the channel transfer function to generate a channel transfer function matrix for each subcarrier of a multicarrier communication channel.

42. The system of claim 41 wherein the base station comprises:

singular value decomposition circuitry to perform singular value decompositions on the channel transfer function matrices to generate the beamforming coefficients; and

beamformers to apply the beamforming coefficients to frequency-domain signals.

43. The system of claim 42 wherein the mobile station comprises circuitry to generate a sampled channel impulse response for channel paths between the mobile station and the base station,

wherein the sampled channel impulse response is represented by a plurality of rays for each channel path, and

wherein each ray is associated with a delay and has an amplitude component and a phase component.

44. A system comprising:

a plurality of substantially omnidirectional antennas to transmit multicarrier communication signals to a base station; and

a multicarrier receiver coupled with the antennas and comprising circuitry to generate a quantized time-domain representation of a channel transfer function, and circuitry to send the quantized time-domain representation of a channel transfer function to a base station for use by the base station in generating beamforming coefficients for use in subsequent transmissions to the mobile station.

45. The system of claim 44 wherein the multicarrier receiver further comprises circuitry to generate a sampled channel impulse response for channel paths between the mobile station and the base station,

wherein the sampled channel impulse response is represented by a plurality of rays for each channel path, and

wherein each ray is associated with a delay and has an amplitude component and a phase component.

46. The system of claim 45 wherein the multicarrier receiver further comprises:

a ray selector to select, for each channel path, most significant rays from the sampled channel impulse response and to calculate a time-domain representation of the channel transfer function for the selected rays; and

a quantizer to quantize the time-domain representation to generate the quantized representation of the channel transfer function for sending to the base station.

47. A machine-accessible medium that provides instructions, which when accessed, cause a machine to perform operations comprising sending a quantized time-domain representation of a channel transfer function from a mobile station to a base station for use by the base station in generating beamforming coefficients for use in subsequent transmissions to the mobile station.

48. The machine-accessible medium of claim 47 wherein the instructions, when further accessed cause the machine to perform operations further comprising estimating a sampled channel impulse response for channel paths between the mobile station and the base station,

wherein the estimated sampled channel impulse response is represented by a plurality of rays for each channel path, and

wherein each ray is associated with a delay and has an amplitude component and a phase component.

49. The machine-accessible medium of claim 48 wherein the instructions, when further accessed cause the machine to perform operations further comprising:

selecting, for each channel path, most significant rays from the estimated sampled channel impulse response;

calculating a time-domain representation of the channel transfer function for the selected rays; and

quantizing the time-domain representation to generate the quantized representation of the channel transfer function for sending to the base station.