Detecting data in multiantenna wireless communication systems
A multiple-input multiple output (MIMO) wireless receiver is provided to detect data in MIMO streams received via a multi-antenna system. A filter based detector performs a first pass at decoding codewords in a MIMO bitstream, and then a parity check is performed to determine that the codewords were decoded correctly. If one or more codewords are decoded correctly, those codewords can be used as a candidate codeword and used to generate a bit log likelihood ratio as an input for a second MIMO detector pass which uses a list based MIMO detector. The first pass with a high speed, simple detector facilitates decreasing the list size for the second, optimum list based detector which helps improve overall throughput.
1. A system, comprising:
a processor; and
a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations, comprising:
receiving a bitstream comprising multiplexed codewords, wherein the bitstream is subject to an inter-stream interference;
performing a first pass with respect to the bitstream to reduce the inter-stream interference using a first multiple-input multiple-output detector;
in response to performing the first pass, determining that a first codeword of the multiplexed codewords passed a parity check and a second codeword of the multiplexed codewords did not pass the parity check;
generating a bit log-likelihood ratio based on the first codeword, wherein the first codeword is a candidate codeword; and
performing a second pass with respect to the bitstream to further reduce the inter-stream interference using a second multiple-input multiple-output detector different from the first multiple-input multiple-output detector, wherein the bit log-likelihood ratio is used as an input for the second pass to reduce a data structure size associated with the second pass.
2. The system of claim 1 , wherein the first multiple-input multiple-output detector uses filter based detection, and wherein the second multiple-input multiple-output detector uses list based detection.
3. The system of claim 2 , wherein the first multiple-input multiple-output detector is at least one of a zero forcing detector, a minimum mean-square error detector, a decision feedback detector, a nulling-canceling detector, or a successive interference cancelation detector.
4. The system of claim 2 , wherein the second multiple-input multiple-output detector is at least one of a maximum likelihood detector, a maximum a posteriori probability detector, a sphere decoding detector, or a list sphere decoding detector.
5. The system of claim 1 , wherein a first list size associated with the first pass is larger than a second list size associated with the second pass.
6. The system of claim 1 , wherein the operations further comprise:
iteratively performing the first pass and the second pass until all codewords of the multiplexed codewords are correctly decoded.
7. The system of claim 1 , wherein the operations further comprise:
transmitting a negative acknowledgement to a transmitter in response to not having decoded all the multiplexed codewords after a predefined number of iterations has passed.
8. The system of claim 1 , wherein the operations further comprise:
transmitting an acknowledgement to a transmitter in response to having decoded all the multiplexed codewords.
9. A method, comprising:
receiving, by a device comprising a processor, a bitstream comprising multiplexed codewords;
performing, by the device, a first decoding pass with a first multiple-input multiple-output detector;
determining, by the device, that a first codeword passes a parity check and a second codeword does not pass the parity check;
generating, by the device, a bit log-likelihood ratio based on the first codeword which is used as a candidate codeword; and
performing, by the device, a second decoding pass with a second multiple-input multiple-output detector, wherein the bit log-likelihood ratio is used as an input for the second decoding pass to reduce a data structure size associated with the second pass.
10. The method of claim 9 , wherein the candidate codeword reduces a list size of the second decoding pass relative to the first decoding pass.
11. The method of claim 9 , wherein the first multiple-input multiple-output detector uses filter based detection, and wherein the second multiple-input multiple-output detector uses list based detection.
12. The method of claim 9 , further comprising:
performing, by the device, iterations of the first decoding pass and the second decoding pass until a predefined number of iterations has passed.
13. The method of claim 12 , further comprising:
transmitting, by the device, a negative acknowledgement to a transmitter in response to not decoding all the multiplexed codewords after the predefined number of iterations has passed.
14. A non-transitory machine-readable storage medium, comprising executable instructions that, when executed by a processor of a device, facilitate performance of operations, comprising:
receiving a signal from a multiple-input multiple-output antenna, the signal comprising multiplexed codewords;
performing a first decoding pass on the multiplexed codewords with a first multiple-input multiple-output detector;
determining that a first codeword of the multiplexed codewords passes a parity check and a second codeword of the multiplexed codewords does not pass the parity check;
generating a bit log-likelihood ratio from an output of the first decoding pass; and
performing a second decoding pass with a second multiple-input multiple-output detector to decode the second codeword, wherein the bit log-likelihood ratio is used as an input for the second decoding pass to reduce a data structure size associated with the second decoding pass.
15. The non-transitory machine-readable storage medium of claim 14 , wherein the generating the bit log-likelihood ratio further comprises generating the bit log-likelihood ratio based on the first codeword.
16. The non-transitory machine-readable storage medium of claim 14 , wherein the operations further comprise:
performing a predefined number of iterations of the first decoding pass and the second decoding pass until all codewords of the multiplexed codewords are correctly decoded or until a predefined number of iterations has passed.
17. The non-transitory machine-readable storage medium of claim 14 , wherein the first multiple-input multiple-output detector uses filter based detection, and wherein the second multiple-input multiple-output detector uses list based detection.
18. The non-transitory machine-readable storage medium of claim 14 , wherein the first multiple-input multiple-output detector is at least one of a zero forcing detector, a minimum mean-square error detector, a decision feedback detector, a nulling-canceling detector, or a successive interference cancelation detector, and wherein the second multiple-input multiple-output detector is at least one of a maximum likelihood detector, a maximum a posteriori probability detector, a sphere decoding detector, or a list sphere decoding detector.
19. The non-transitory machine-readable storage medium of claim 14 , wherein the operations further comprise:
iteratively performing the first decoding pass and the second decoding pass until all codewords of the multiplexed codewords are correctly decoded.
20. The non-transitory machine-readable storage medium of claim 19 , wherein the operations further comprise:
transmitting a negative acknowledgement to a transmitter of the signal in response to not having decoded all the multiplexed codewords after a predefined number of iterations has passed.