Simplified practical rank and mechanism, and associated method, to adapt MIMO modulation in a multi-carrier system with feedback
View Patent ↗A method of adapting transmission parameters in a multicarrier communication system having multiple transmit antennas and/or multiple receive antennas, whereby a statistical parameter of a wideband channel is computed, one type of matrix modulation scheme is selected to be used for a given multicarrier modulation symbol, one type of signal constellation is selected to be used for a given multicarrier modulation symbol, and one concatenated channel coding rate is selected to be used for a given multicarrier modulation symbol. Multicarrier modulation symbols are then transmitted using the selected matrix modulation scheme, signal constellation, and concatenated channel coding rate.
1. A method of adapting transmission parameters in a multicarrier communication system having multiple transmit antennas and/or multiple receive antennas, the method comprising steps of:
computing a statistical parameter of a wideband channel;
using the value of said statistical parameter to select one type of matrix modulation scheme to be used for a given multicarrier modulation symbol;
selecting one type of signal constellation to be used for a given multicarrier modulation symbol;
selecting one concatenated channel coding rate to be used for a given multicarrier modulation symbol; and
transmitting multicarrier modulation symbols using the selected matrix modulation scheme, signal constellation, and concatenated channel coding rate.
2. The method of claim 1 , wherein the step of computing the statistical parameter is performed only on a subset of the total subcarriers.
3. The method of claim 1 , wherein the step of computing the statistical parameter is performed only on a subset of the total subcarriers, which subcarriers are selected so that the spacing between subcarriers is substantially equal to the channel coherence bandwidth.
4. The method of claim 1 , wherein the step of computing the statistical parameter is performed only on a subset of the total subcarriers, which subcarriers are selected so that the spacing between subcarriers is less than the channel coherence bandwidth.
5. The method of claim 1 , wherein the step of computing the statistical parameter is performed only on a subset of the total subcarriers, and is computed with reference to the expected value of the ratio of the second smallest channel matrix eigenvalue absolute value to the largest channel eigenvalue absolute value.
6. The method of claim 1 , wherein said statistical parameter is an approximate practical rank.
7. The method of claim 1 , wherein the steps of selecting a matrix modulation scheme, signal constellation, and concatenated channel coding rate are performed to substantially maximize data throughput.
8. The method of claim 1 , wherein the step of computing a statistical parameter of a wideband channel is performed in conjunction with a database of values, where, for every SINR value received, an estimated frame error rate F(κ,R) is available for every (M,C) pair when a given concatenated channel coding rate R is adopted.
9. A method of adapting transmission parameters in a multicarrier communication system having multiple transmit antennas and/or multiple receive antennas, the method comprising steps of:
computing a statistical parameter of a wideband channel and computing an SNIR;
using the value of said statistical parameter and SNIR to select one type of matrix modulation scheme to be used for a given multicarrier modulation symbol;
selecting one type of signal constellation to be used for a given multicarrier modulation symbol;
selecting one concatenated channel coding rate to be used for a given multicarrier modulation symbol; and
transmitting multicarrier modulation symbols using the selected matrix modulation scheme, signal constellation, and concatenated channel coding rate.
10. The method of claim 9 , wherein the step of computing the statistical parameter is performed only on a subset of the total subcarriers.
11. The method of claim 9 , wherein the step of computing the statistical parameter is performed only on a subset of the total subcarriers, which subcarriers are selected so that the spacing between subcarriers is substantially equal to the channel coherence bandwidth.
12. The method of claim 9 , wherein the step of computing the statistical parameter is performed only on a subset of the total subcarriers, which subcarriers are selected so that the spacing between subcarriers is less than the channel coherence bandwidth.
13. The method of claim 9 , wherein the step of computing the statistical parameter is performed only on a subset of the total subcarriers, and is computed with reference to the expected value of the ratio of the second smallest channel matrix eigenvalue absolute value to the largest channel eigenvalue absolute value.
14. The method of claim 9 , wherein said statistical parameter is an approximate practical rank.
15. The method of claim 9 , wherein the steps of selecting a matrix modulation scheme, signal constellation, and concatenated channel coding rate are performed to substantially maximize data throughput.
16. The method of claim 9 , wherein the step of computing a statistical parameter of a wideband channel and SNIR is performed in conjunction with a database of values, where, for every SINR value received, an estimated frame error rate F(κ,R) is available for every (M,C) pair when a given concatenated channel coding rate R is adopted.
17. An apparatus for adapting transmission parameters in a multicarrier communication system having multiple transmit antennas and/or multiple receive antennas, the apparatus being characterized by:
a first computational portion configured for computing a statistical parameter of a wideband channel and for computing an SNIR;
a second computational portion configured for using the value of said statistical parameter and SNIR to select one type of matrix modulation scheme to be used for a given multicarrier modulation symbol, for selecting one type of signal constellation to be used for a given multicarrier modulation symbol, and for selecting one concatenated channel coding rate to be used for a given multicarrier modulation symbol; and
the multiple transmitter antennas being configured for transmitting multicarrier modulation symbols using the selected matrix modulation scheme, signal constellation, and concatenated channel coding rate.
18. The apparatus of claim 17 , wherein the first computational portion is configured for computing a statistical parameter of a wideband channel and SNIR only on a subset of the total subcarriers.
19. The apparatus of claim 17 , wherein the first computational portion is configured for computing a statistical parameter of a wideband channel and SNIR only on a subset of the total subcarriers, which subcarriers are selected so that the spacing between subcarriers is substantially equal to the channel coherence bandwidth.
20. The apparatus of claim 17 , wherein the first computational portion is configured for computing a statistical parameter of a wideband channel and SNIR only on a subset of the total subcarriers, which subcarriers are selected so that the spacing between subcarriers is less than the channel coherence bandwidth.
21. The apparatus of claim 17 , wherein the first computational portion is configured for computing a statistical parameter of a wideband channel and SNIR only on a subset of the total subcarriers, which computing is with reference to the expected value of the ratio of the second smallest channel matrix eigenvalue absolute value to the largest channel eigenvalue absolute value.