Method and apparatus for combining space-frequency block coding, spatial multiplexing and beamforming in a MIMO-OFDM system

• US 20060133530A1
• Filed: 10/20/2005
• Published: 06/22/2006
• Est. Priority Date: 11/12/2004
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Olesen, Robert Lind, Ozluturk, Fatih, Koo, Chang-Soo, Bultan, Aykut, Kwak, Jaeyoung
• Granted Patent: US 8,130,855 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/04 using frequency diversity
• CPC Class Codes: H04L 1/0606 Space-frequency coding
• CPC Class Codes: H04L 25/0248 Eigen-space methods
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT

Abstract

A method and apparatus for combining space-frequency block coding (SFBC), spatial multiplexing (SM) and beamforming in a multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system. The system includes a transmitter with a plurality of transmit antennas and a receiver with a plurality of receive antennas. The transmitter generates at least one data stream and a plurality of spatial streams. The number of generated spatial streams is based on the number of the transmit antennas and the number of the receive antennas. The transmitter determines a transmission scheme in accordance with at least one of SFBC, SM and beam forming. The transmitter transmits data in the data stream to the receiver based on the selected transmission scheme.

Claims

1. In a multiple-input multiple-output (MIMO) orthogonal frequency division multiplex (OFDM) system including a transmitter with a plurality of transmit antennas and a receiver with a plurality of receive antennas, a method for transmitting data from the transmitter to the receiver, the method comprising:

(a) the transmitter generating at least one data stream;

(b) the transmitter generating a plurality of spatial streams, the number of the generated spatial streams being determined based on the number of the transmit antennas and the number of the receive antennas;

(c) the transmitter determining a transmission scheme in accordance with at least one of space-frequency block coding (SFBC), spatial multiplexing (SM) and beamforming; and

(d) the transmitter transmitting data in the data stream to the receiver based on the selected transmission scheme.

2. The method of claim 1 wherein frequency diversity (FD) is utilized in transmission of the data, whereby the sub-carriers are divided into two groups and one group transmits data symbols and the other group transmits a complex conjugate of the data symbols.

3. The method of claim 1 wherein more than two spatial streams are generated for the SFBC, whereby Alamouti-type SFBC is applied to OFDM symbols.

4. The method of claim 1 wherein and both frequency diversity (FD) and non-FD are simultaneously applied to the spatial streams.

5. The method of claim 4 wherein more than two spatial streams are generated such that a combination of SFBC, FD and non-FD is applied to the spatial streams.

6. The method of claim 1 further comprising:

obtaining channel state information (CSI) between the transmitter and the receiver for each sub-carrier, whereby the transmission scheme is determined based on the CSI.

7. The method of claim 6 wherein a beam having a largest singular value obtained by singular value decomposition (SVD) of a channel matrix is selected when beam selection is utilized.

8. The method of claim 7 wherein the SFBC is applied on two spatial streams having lower singular values obtained by the SVD of a channel matrix.

9. The method of claim 6 wherein the CSI is fed back to the transmitter from the receiver.

10. The method of claim 6 wherein the CSI is obtained by the transmitter using channel reciprocity.

11. The method of claim 1 wherein the transmission scheme is determined without channel state information (CSI) and beamforming is performed with a fixed beamforming matrix.

12. The method of claim 1 wherein the number of data stream is determined by a modulation and coding scheme.

13. In a multiple-input multiple-output (MIMO) orthogonal frequency division multiplex (OFDM) system, a transmitter comprising:

at least two transmit antennas;

a channel coder configured to perform a channel coding on input data;

a beamformer configured to perform eigen-beamforming based on channel state information (CSI) to distribute eigen-beams to the transmit antennas; and

a plurality of inverse fast Fourier transform (IFFT) units for performing IFFT by converting outputs of the beamformer to data in time domain for transmission, whereby the input data is transmitted using spatial multiplexing (SM).

14. The transmitter of claim 13 wherein the input data is transmitted with frequency diversity (FD), whereby sub-carriers are divided into two groups and one group transmits data symbols and the other group transmits a complex conjugate of the data symbols.

15. The transmitter of claim 13 further comprising a multiplexer for generating a plurality of independent data streams, whereby the plurality of data streams are separately transmitted.

16. The transmitter of claim 13 further comprising a plurality of space-frequency block coding (SFBC) units configured to perform SFBC coding of the data streams for each pair of sub-carriers.

17. The transmitter of claim 16 wherein more than two eigen-beams are generated and two eigen-beams are used for SFBC and the remaining eigen-beams are used for SM.

18. The transmitter of claim 17 wherein the input data is transmitted with frequency diversity (FD), whereby for the eigen-beams used for SM, sub-carriers are divided into two groups and one group transmits data symbols and the other group transmits a complex conjugate of the data symbols.

19. The transmitter of claim 17 wherein the eigen-beams for SFBC are selected based on singular value decomposition (SVD) of a channel matrix.

20. The transmitter of claim 19 wherein eigen-beams having smaller singular values are selected for SFBC.

21. The transmitter of claim 13 wherein a portion of eigen-beams having a larger singular value which is obtained by singular value decomposition (SVD) are selected and the input data is transmitted via the selected eigen-beams.

22. In a multiple-input multiple-output (MIMO) orthogonal frequency division multiplex (OFDM) system, a transmitter comprising:

at least two transmit antennas;

a channel coder configured to perform a channel coding on input data;

a beamformer network configured to generate a plurality of beams in accordance with a fixed beamforming matrix; and

a plurality of inverse fast Fourier transform (IFFT) units for performing IFFT by converting outputs from the beamformer network to data in time domain for transmission, whereby the input data is transmitted using spatial multiplexing (SM).

23. The transmitter of claim 22 wherein the input data is transmitted with frequency diversity (FD), whereby sub-carriers are divided into two groups and one group transmits data symbols and the other group transmits a complex conjugate of the data symbols.

24. The transmitter of claim 22 further comprising a multiplexer for generating a plurality of independent data streams, whereby the plurality of data streams are separately transmitted.

25. The transmitter of claim 22 further comprising a plurality of space-frequency block coding (SFBC) units configured to perform SFBC coding of the data streams for each pair of sub-carriers.

26. The transmitter of claim 25 wherein more than two beams are generated and two beams are used for SFBC and the remaining beams are used for SM.

27. The transmitter of claim 26 wherein the input data is transmitted with frequency diversity (FD), whereby for the beams used for SM, sub-carriers are divided into two groups where one group transmits data symbols and the other group transmits a complex conjugate of the data symbols.

28. In a multiple-input multiple-output (MIMO) orthogonal frequency division multiplex (OFDM) system, a transmitter including at least two transmit antennas and an integrated circuit (IC), the IC comprising:

a channel coder configured to perform a channel coding on input data;

a beamformer configured to perform eigen-beamforming based on channel state information (CSI) to distribute eigen-beams to the transmit antennas; and

a plurality of inverse fast Fourier transform (IFFT) units for performing IFFT by converting outputs of the beamformer to data in time domain for transmission, whereby the input data is transmitted using spatial multiplexing (SM).

29. The IC of claim 28 wherein the input data is transmitted with frequency diversity (FD), whereby sub-carriers are divided into two groups and one group transmits data symbols and the other group transmits a complex conjugate of the data symbols.

30. The IC of claim 28 further comprising a multiplexer for generating a plurality of independent data streams, whereby the plurality of data streams are separately transmitted.

31. The IC of claim 28 further comprising a plurality of space-frequency block coding (SFBC) units configured to perform SFBC coding of the data streams for each pair of sub-carriers.

32. The IC of claim 31 wherein more than two eigen-beams are generated and two eigen-beams are used for SFBC and the remaining eigen-beams are used for SM.

33. The IC of claim 32 wherein the input data is transmitted with frequency diversity (FD), whereby for the eigen-beams used for SM, sub-carriers are divided into two groups and one group transmits data symbols and the other group transmits a complex conjugate of the data symbols.

34. The IC of claim 32 wherein the eigen-beams for SFBC are selected based on singular value decomposition (SVD) of a channel matrix.

35. The IC of claim 34 wherein eigen-beams having smaller singular values are selected for SFBC.

36. The IC of claim 28 wherein a portion of eigen-beams having a larger singular value which is obtained by singular value decomposition (SVD) are selected and the input data is transmitted via the selected eigen-beams.

37. In a multiple-input multiple-output (MIMO) orthogonal frequency division multiplex (OFDM) system, a transmitter including at least two transmit antennas and an integrated circuit (IC), the IC comprising;

a channel coder configured to perform a channel coding on input data;

a beamformer network configured to generate a plurality of beams in accordance with a fixed beamforming matrix; and

a plurality of inverse fast Fourier transform (IFFT) units for performing IFFT by converting outputs from the beamformer network to data in time domain for transmission, whereby the input data is transmitted using spatial multiplexing (SM).

38. The IC of claim 37 wherein the input data is transmitted with frequency diversity (FD), whereby sub-carriers are divided into two groups and one group transmits data symbols and the other group transmits a complex conjugate of the data symbols.

39. The IC of claim 37 further comprising a multiplexer for generating a plurality of independent data streams, whereby the plurality of data streams are separately transmitted.

40. The IC of claim 37 further comprising a plurality of space-frequency block coding (SFBC) units configured to perform SFBC coding of the data streams for each pair of sub-carriers.

41. The IC of claim 40 wherein more than two beams are generated and two beams are used for SFBC and the remaining beams are used for SM.

42. The IC of claim 41 wherein the input data is transmitted with frequency diversity (FD), whereby for the beams used for SM, sub-carriers are divided into two groups where one group transmits data symbols and the other group transmits a complex conjugate of the data symbols.