Method and apparatus for implementing space time processing with unequal modulation and coding schemes
A method and apparatus for implementing spatial processing with unequal modulation and coding schemes (MCSs) or stream-dependent MCSs are disclosed. Input data may be parsed into a plurality of data streams, and spatial processing is performed on the data streams to generate a plurality of spatial streams. An MCS for each data stream is selected independently. The spatial streams are transmitted via multiple transmit antennas. At least one of the techniques of space time block coding (STBC), space frequency block coding (SFBC), quasi-orthogonal Alamouti coding, time reversed space time block coding, linear spatial processing and cyclic delay diversity (CDD) may be performed on the data/spatial streams. An antennal mapping matrix may then be applied to the spatial streams. The spatial streams are transmitted via multiple transmit antennas. The MCS for each data stream may be determined based on a signal-to-noise ratio of each spatial stream associated with the data stream.
1. A method for implementing spatial data processing with unequal modulation and coding schemes (MCSs), the method comprising:
generating a first spatial stream and a second spatial stream;
performing a space time block coding (STBC) processing on the first spatial stream to generate two STBC-processed data streams;
performing a cyclic delay diversity (CDD) processing on the second spatial stream; and
transmitting simultaneously the STBC-processed data streams and the CDD-processed second spatial stream in parallel with at least three antennas, the STBC-processed data streams being transmitted via at least two antennas, respectively, and the CDD-processed second spatial stream being transmitted via at least one additional antenna, wherein an MCS is selected for each spatial stream independently of the other spatial stream and each of the spatial streams is modulated with the selected MCS for each spatial stream.
2. The method of claim 1 wherein an antenna mapping matrix is multiplied to the spatial streams.
3. The method of claim 2 wherein the antenna mapping matrix is an identity matrix.
4. The method of claim 2 wherein the antenna mapping matrix is for spatial spreading.
5. The method of claim 2 wherein the antenna mapping matrix is a channel-specific steering matrix.
6. The method of claim 5 wherein the antenna mapping matrix includes a set of channel eigenvectors.
7. The method of claim 1 wherein the MCS for each data stream is determined based on a signal-to-noise ratio of each spatial stream associated with the data stream.
8. A method for implementing spatial data processing with unequal modulation and coding schemes (MCSs), the method comprising:
receiving data streams with at least two receive antennas; and
performing a spatial decoding on the data streams to recover a plurality of spatial streams that are transmitted simultaneously via at least three antennas including a first spatial stream transmitted using space time block coding (STBC) via at least one pair of antennas and a second spatial stream transmitted using cyclic delay diversity (CDD) via another antenna, an MCS being used for each spatial stream independently of an MCS for the other spatial stream.
9. A transmitter for implementing spatial data processing with unequal modulation and coding schemes (MCSs), the transmitter comprising:
a spatial processor for performing space time block coding (STBC) on a first spatial stream among a plurality of spatial streams to generate two STBC-processed data streams, and performing a cyclic delay diversity (CDD) processing on a second spatial stream, an MCS being selected for each spatial stream independently of an MCS for the other spatial stream and each of the spatial streams being modulated with a selected MCS for each spatial stream; and
at least three transmit antennas for simultaneously transmitting the two STBC-processed data streams and the CDD-processed second spatial stream in parallel, the STBC-processed data streams being transmitted via at least two antennas, respectively, and the CDD-processed second spatial stream being transmitted via at least one additional antenna.
10. The transmitter of claim 9 wherein the spatial processor is configured to apply an antenna mapping matrix to the spatial streams.
11. The transmitter of claim 10 wherein the antenna mapping matrix is an identity matrix.
12. The transmitter of claim 10 wherein the antenna mapping matrix is for spatial spreading.
13. The transmitter of claim 10 wherein the antenna mapping matrix is a channel-specific steering matrix.
14. The transmitter of claim 13 wherein the antenna mapping matrix includes a set of channel eigenvectors.
15. The transmitter of claim 9 wherein the MCS for each data stream is determined based on a signal-to-noise ratio of each spatial stream associated with the data stream.
16. A receiver for implementing spatial data processing with unequal modulation and coding schemes (MCSs), the receiver comprising:
at least two receive antennas for receiving a plurality of data streams; and
a spatial decoder for performing a spatial decoding on the data streams to recover a plurality of spatial streams that are simultaneously transmitted via at least three antennas including a first spatial stream transmitted using space time block coding (STBC) via at least one pair of antennas and a second spatial stream transmitted via at least one another antenna, the second spatial stream being processed by a cyclic delay diversity (CDD) processing, an MCS being used for each spatial stream independently of an MCS for the other spatial stream.