Eigenvalue decomposition precoding matrix index selection
View Patent ↗A method and system for selecting precoding matrix index are herein disclosed. The method includes determining a precoder and candidate beams, selecting base beams based on a correlation power between the determined precoder and determined candidate beams, and estimating amplitude coefficients and cophase coefficients by projecting a channel on the selected base beams.
1. A method for selecting precoding matrix index (PMI), comprising:
determining a precoder and candidate beams;
selecting base beams based on a correlation power between the determined precoder and determined candidate beams; and
estimating amplitude coefficients and cophase coefficients by projecting a channel on the selected base beams.
2. The method of claim 1 , wherein the precoder is determined by a reduced dimension singular value decomposition (SVD).
3. The method of claim 2 , wherein the reduced dimension SVD reduces the precoder determination from a 4×4 SVD calculation to a 2×2 SVD calculation.
4. The method of claim 1 , wherein selecting base beams further comprises selecting integer indices.
5. The method of claim 4 , wherein selecting integer indices is based on linear complexity in a multiple input multiple output (MIMO) system.
6. The method of claim 1 , wherein selecting base beams further comprises selecting fractional indices.
7. The method of claim 1 , wherein the estimating the amplitude and cophase coefficients is based on a wide band amplitude scaling factor {circumflex over (p)} r,l,i WB and a per subband amplitude scaling adjustment factor {circumflex over (p)} r,l,i,k SB .
8. The method of claim 1 , wherein the projecting the channel on the selected base beams comprises identifying optimal linear combination coefficients (LCCs).
9. The method of claim 1 , wherein the projecting the channel on the selected base beams comprises projecting the channel on a j-th PMI subband to a space of a beam selection matrix.
10. The method of claim 9 , wherein the projecting the channel on the j-th PMI subband to the space of the beam selection matrix comprises determining optimum precoding vectors.
11. A system for selecting precoding matrix index (PMI), comprising:
a transmitter;
a receiver; and
a processor configured to:
determine a precoder and candidate beams;
select base beams based on a correlation power between the determined precoder and determined candidate beams; and
estimate amplitude coefficients and cophase coefficients by projecting a channel on the selected base beams.
12. The system of claim 11 , wherein the processor is configured to determine the precoder by a reduced dimension singular value decomposition (SVD).
13. The system of claim 12 , wherein the reduced dimension SVD reduces the precoder determination from a 4×4 SVD calculation to a 2×2 SVD calculation.
14. The system of claim 11 , wherein the processor is further configured to select base beams by selecting integer indices.
15. The system of claim 14 , wherein the processor is further configured to select integer indices based on linear complexity in a multiple input multiple output (MIMO) system.
16. The system of claim 11 , wherein the processor is further configured to select base beams by selecting fractional indices.
17. The system of claim 11 , wherein the processor is further configured to estimate the amplitude and cophase coefficients based on a wide band amplitude scaling factor {circumflex over (p)} r,l,i WB and a per subband amplitude scaling adjustment factor {circumflex over (p)} r,l,i,k SB .
18. The system of claim 11 , wherein the projecting the channel on the selected base beams comprises identifying optimal linear combination coefficients (LCCs).
19. The system of claim 11 , wherein the projecting the channel on the selected base beams comprises projecting the channel on a j-th PMI subband to a space of a beam selection matrix.
20. The system of claim 19 , wherein the projecting the channel on the j-th PMI subband to the space of the beam selection matrix comprises determining optimum precoding vector.