Method and system for an adaptive VBLAST receiver for wireless multiple input multiple output (MIMO) detection
View Patent ↗Various aspects of a system for an adaptive VBLAST receiver for wireless MIMO detection may comprise utilizing log likelihood ratios (LLR) to selectively cancel interference in a received signal when information contained in one or more layers is encoded. Following the selective cancellation of interference, further computations may be performed on the residual received signal. Various aspects of the invention may comprise a linear detector with improved performance in comparison to some conventional VBLAST receivers. Performance may be measured by, for example, a packet error rate (PER) for a given signal to noise ratio (SNR) associated with the received signal.
1. A method for processing received information in a communication system, the method comprising:
performing by one or more processors and/or circuits:
wirelessly receiving a signal comprising a plurality of received symbols in a multiple input multiple output communication system;
selectively canceling an estimate of at least one of said plurality of received symbols in said received signal to generate a residual signal;
computing a magnitude comprising a numerical difference between a constellation point and said at least one of said plurality of received symbols;
computing at least one subsequent magnitude comprising a numerical difference between a subsequent constellation point and said at least one of said plurality of received symbols; and
computing a log likelihood ratio according to a ratio based on said magnitude and said subsequent magnitude.
2. The method according to claim 1 , comprising computing a minimum log likelihood ratio of said computed log likelihood ratio.
3. The method according to claim 2 , comprising comparing said computed minimum log likelihood ratio to a threshold value.
4. The method according to claim 3 , comprising performing said selective canceling based on a result of said comparing.
5. A system for processing received information in a communication system, the system comprising:
one or more circuits that are operable to wirelessly receive a signal comprising a plurality of received symbols in a multiple input multiple output communication system;
said one or more circuits are operable to selectively cancel an estimate of at least one of said plurality of received symbols in said received signal to generate a residual signal;
said one or more circuits are operable to compute a magnitude comprising a numerical difference between a constellation point and said at least one of said plurality of received symbols;
said one or more circuits are operable to compute at least one subsequent magnitude comprising a numerical difference between a subsequent constellation point and said at least one of said plurality of received symbols; and
said one or more circuits are operable to compute a log likelihood ratio according to a ratio based on said magnitude and said subsequent magnitude.
6. The system according to claim 5 , wherein said one or more circuits are operable to compute a minimum log likelihood ratio of said computed log likelihood ratio.
7. The system according to claim 6 , wherein said one or more circuits are operable to compare said computed minimum log likelihood ratio to a threshold value.
8. The system according to claim 7 , wherein said one or more circuits are operable to perform said selective canceling based on a result of said comparing.
9. The method according to claim 1 , wherein said numerical difference comprises a Euclidean distance.
10. The method according to claim 1 , comprising computing a final occurrence of said selective canceling.
11. The method according to claim 10 , comprising computing an estimated value for at least one of said plurality of received symbols when said final occurrence of said residual signal comprises a value that is statistically greater than 0.
12. The method according to claim 1 , comprising generating a channel estimate matrix based on said received signal.
13. The method according to claim 12 , comprising generating a sorted order among said plurality of received symbols based on said generated channel estimate matrix.
14. The method according to claim 13 , comprising computing said log likelihood ratio for each bit in a corresponding one of said plurality of received symbols.
15. The system according to claim 5 , wherein said numerical difference comprises a Euclidean distance.
16. The system according to claim 5 , wherein said one or more circuits are operable to compute a final occurrence of said selective canceling.
17. The system according to claim 16 , wherein said one or more circuits are operable to compute an estimated value for at least one of said plurality of received symbols when said final occurrence of said residual signal comprises a value that is statistically greater than 0.
18. The system according to claim 5 , wherein said one or more circuits are operable to generate a channel estimate matrix based on said received signal.
19. The system according to claim 18 , wherein said one or more circuits are operable to generate a sorted order among said plurality of received symbols based on said generated channel estimate matrix.
20. The system according to claim 19 , wherein said one or more circuits are operable to compute said log likelihood ratio for each bit in a corresponding one of said plurality of received symbols.