Method and system for SFBC/STBC in a communication diversity system using angle feedback

• US 8,254,507 B2
• Filed: 09/28/2007
• Issued: 08/28/2012
• Est. Priority Date: 06/18/2007
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Kim, Joonsuk, Ariyavisitakul, Sirikiat, Seshadri, Nambirajan
• Primary Examiner(s): Ometz, David
• Assistant Examiner(s): Garcia, Santiago
• Application Number:
  US11/864,611
• Publication Number:
  US 20080311873A1
• Time in Patent Office: 1,796 Days
• Field of Search: 375/347
• US Class Current: 375/347
• CPC Class Codes: H04B 7/0634 Antenna weights or vector/matrix coefficients
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/068 using space frequency diversity space-frequency coding H04L1/0606
• CPC Class Codes: H04B 7/0891 Space-time diversity rake receivers H04B1/7115; space-time decoding H04L1/0631
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/04 using frequency diversity
• CPC Class Codes: H04L 1/0675 characterised by the signaling
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals

Abstract

Aspects of a system for STBC/SFBC in a communication system using angle feedback may include a receiver, which enables reception of signals via a plurality of receiving antennas. The receiver may enable computation of a rotation factor value based on the received signals and utilization of the computed rotation factor value to receive subsequent signals via the plurality of receiving antennas. The received signals may comprise preamble data. The receiver may enable computation of channel estimate values based on the received preamble data. A rotation angle value may be computed based on the computed channel estimate values. The rotation factor value may be computed based on the computed rotation angle value. The receiver may enable transmission of feedback information comprising the computed rotation factor and/or the computed rotation angle.

Claims

1. A method for processing signals in a communication system comprising:

receiving signals via a plurality of receiving antennas, in which a respective decoder of a plurality of decoders is utilized to decode signals received at a respective receiving antenna;

decoding in each decoder to calculate respective channel estimation for signals received at a respective receiving antenna for that decoder, wherein the channel estimation is calculated based on preamble data in the signals and a transfer function matrix is generated in each decoder to calculate the respective channel estimation and a square matrix;

computing a complex-valued rotation factor in each decoder to minimize crosstalk in respect to the calculated channel estimation for that decoder;

selecting one of the complex-valued rotation factors which produces a least amount of crosstalk based on a preselected computation; and

transmitting the selected complex-valued rotation factor to a transmitter that transmitted the signals to utilize the selected complex-valued rotation factor for subsequent signals sent to the receiving antennas.

2. The method according to claim 1, comprising using a Hermitian matrix in each decoder to calculate the channel estimation.

3. The method according to claim 1, comprising computing each complex-valued rotation factor based on a corresponding rotation angle.

4. The method according to claim 3, comprising transmitting the rotation angle corresponding to the selected complex-valued rotation factor.

5. The method according to claim 1, comprising generating the square matrix by pre-multiplying the transfer function matrix by a transformed version of the transfer function matrix.

6. The method according to claim 5, wherein off-diagonal elements in the square matrix comprise crosstalk terms.

7. The method according to claim 6, wherein the crosstalk is derived from the crosstalk terms in the square matrix.

8. A system for processing signals comprising:

one or more circuits that enable reception of signals via a plurality of receiving antennas, wherein the one or more circuits include a plurality of decoders, in which a respective decoder of the plurality of decoders is utilized to decode signals received at a respective receiving antenna;

each decoder to calculate respective channel estimation for signals received at a respective receiving antenna for that decoder, wherein the channel estimation is calculated based on preamble data in the signals and wherein each decoder to generate a transfer function matrix to calculate the respective channel estimation and a square matrix, and each decoder to compute a complex-valued rotation factor to minimize crosstalk in respect to the calculated channel estimation for that decoder;

the one or more circuits to select one of the complex-valued rotation factors which produces a least amount of crosstalk based on a preselected computation; and

the one or more circuits to transmit the selected complex-valued rotation factor to a transmitter that transmitted the signals to utilize the selected complex valued rotation factor for subsequent signals sent to the receiving antennas.

9. The system according to claim 8, wherein each decoder to use a Hermitian matrix to calculate the channel estimation.

10. The system according to claim 8, wherein computation of each complex-valued rotation factor is based on a corresponding rotation angle.

11. The system according to claim 10, wherein the one or more circuits to transmit the rotation angle corresponding to the selected complex-valued rotation factor.

12. The system according to claim 8, wherein each decoder to generate the square matrix by pre-multiplying the transfer function matrix by a transformed version of the transfer function matrix.

13. The system according to claim 12, wherein off diagonal elements in the square matrix comprise crosstalk terms.

14. The system according to claim 13, wherein the crosstalk is derived from the crosstalk terms in the square matrix.

15. An apparatus comprising:

one or more radio front end that enable reception of wireless signals via a plurality of receiving antennas;

a plurality of decoders coupled to the one or more radio front end, in which a respective decoder of the plurality of decoders is utilized to decode signals received at a respective receiving antenna, each decoder to calculate respective channel estimation for signals received at a respective receiving antenna for that decoder, wherein the channel estimation is calculated based on preamble data in the signals and wherein each decoder to generate a transfer function matrix to calculate the respective channel estimation and a square matrix, and each decoder to compute a complex-valued rotation factor to minimize crosstalk in respect to the calculated channel estimation for that decoder; and

a processor to select one of the complex-valued rotation factors which produces a least amount of crosstalk based on a preselected computation, in which the selected complex-valued rotation factor is to be transmitted by the one or more radio front end to a transmitter that transmitted the signals to utilize the selected complex valued rotation factor for subsequent signals sent to the receiving antennas.

16. The apparatus according to claim 15, wherein each decoder to use a Hermitian matrix to calculate the channel estimation.

17. The apparatus according to claim 15, wherein computation of each complex-valued rotation factor is based on a corresponding rotation angle.

18. The apparatus according to claim 17, wherein the one or more circuits to transmit the rotation angle corresponding to the selected complex-valued rotation factor.

19. The apparatus according to claim 15, wherein each decoder to generate the square matrix by pre-multiplying the transfer function matrix by a transformed version of the transfer function matrix and wherein off diagonal elements in the square matrix comprise crosstalk terms.

20. The apparatus according to claim 19, wherein the crosstalk is derived from the crosstalk terms in the square matrix.