Method and device for operating a precoded MIMO system
View Patent ↗A method is provided for generating precoder data ( 600 ), comprising: obtaining transmit power data indicative of a transmit power of a plurality of multiple-input/multiple-output signals ( 610 ); obtaining signal quality data, the signal quality data including at least one measure of a quality of the plurality of multiple-input/multiple-output signals ( 620, 630 ); obtaining channel data with respect to a wireless channel, the channel data including a measure of respective channel parameters of each of a plurality of channel paths in the wireless channel ( 620, 630 ); constraining one or more system performance parameters ( 640 ); and determining first and second precoder diagonal values (w A and w B ) based on the signal quality data, the transmit power data, the channel data, and the one or more constrained system performance parameters ( 650 ).
1. A method for generating multiple-input/multiple-output signals, comprising:
obtaining first and second precoder diagonal values;
generating all elements in an M-by-M diagonal precoding matrix based only on the first and second precoder diagonal values, where M is an integer greater than 2;
receiving a stream of data bits;
encoding a plurality of data bits in the stream of bits into a plurality of symbols chosen from a set symbol constellation;
encoding the plurality of symbols into a space-time-code matrix according to a set space time code;
multiplying the space-time-code matrix by the precoding matrix to generate a transmit matrix containing a plurality of modified symbols.
2. The method of claim 1 , wherein the first precoder diagonal value forms both a corner element in the precoding matrix, and an internal element in the precoding matrix, the internal element being adjacent to the corner element.
3. The method of claim 1 , wherein the first and second precoder diagonal values are obtained as a vector.
4. The method of claim 1 , wherein the diagonal preceding matrix is one of a (4×4) diagonal matrix or a (3×3) diagonal matrix.
5. The method of claim 1 , wherein the diagonal precoding matrix is designed to improve a minimum mean square estimation successive interference cancellation process on a received copy of the transmit matrix, as compared to a received copy of the space-time-code matrix.
6. The method of claim 1 , wherein the method is implemented using an integrated circuit.
7. A multiple-input/multiple-output apparatus, comprising a Transmitter/receiver pair configured to:
obtain first and second precoder diagonal values;
generate all elements in an M-by-M diagonal precoding matrix based only on the first and second precoder diagonal values, where M is an integer greater than 2;
receive a stream of data bits;
encode a plurality of data bits in the stream of bits into a plurality of symbols chosen from a set symbol constellation;
encode the plurality of symbols into a space-time-code matrix according to a set space time code;
multiply the space-time-code matrix by the precoding matrix to generate a transmit matrix containing a plurality of modified symbols.
8. The apparatus of claim 7 , wherein the first and second precoder diagonal values are selected from a limited set of possible values.
9. The apparatus of claim 7 , wherein the first and second precoder diagonal values are selected from a set constellation of vector values.
10. The apparatus of claim 7 , further configured to transmit the first and second precoder diagonal values to a remote device.
11. The apparatus of claim 7 , wherein the first precoder diagonal value forms both a corner element in the precoding matrix and an internal element in the precoding matrix, the internal element being adjacent to the corner element.
12. The apparatus of claim 7 , wherein the first and second precoder diagonal values are obtained as a vector.
13. The apparatus of claim 7 , wherein the diagonal precoding matrix is one of a (4×4) diagonal matrix or a (3×3) diagonal matrix.
14. The apparatus of claim 7 , wherein the diagonal precoding matrix is designed to improve a minimum mean square estimation successive interference cancellation process on a received copy of the transmit matrix, as compared to a received copy of the space-time-code matrix.
15. The apparatus of claim 7 , wherein the apparatus comprises an integrated circuit.