Buffer management in a turbo equalization system
A plurality of metrics associated with a plurality of partially decoded codewords is obtained. The plurality of partially decoded codewords has been processed at least once by a first soft output decoder and a second soft output decoder and the plurality of partially decoded codewords is stored in a memory. At least one of the plurality of partially decoded codewords is selected based at least in part on the plurality of metrics; the memory is instructed to vacate the at least one selected codeword.
1. A method, comprising:
obtaining a plurality of metrics associated with a plurality of partially decoded codewords, wherein:
the plurality of partially decoded codewords has been processed at least once by a first soft output decoder and a second soft output decoder; and
the plurality of partially decoded codewords is stored in a memory;
determining that a utilized storage capacity of the memory has reached a threshold;
in response to the determination that the utilized storage capacity of the memory has reached the threshold, selecting at least one of the plurality of partially decoded codewords based at least in part on the plurality of metrics; and
using a processor to instruct the memory to vacate the at least one selected codeword, wherein vacating the at least one selected codeword includes discarding the at least one selected codeword from the memory.
2. The method of claim 1 , wherein the first soft output decoder includes a soft output Viterbi algorithm (SOVA) decoder.
3. The method of claim 1 , wherein the second soft output decoder includes a low-density parity-check (LDPC) decoder.
4. The method of claim 1 , wherein the plurality of metrics is associated with one or more of the following: a number of unsatisfied parity checks, an average of certainty values, a median of certainty values, or log-likelihood ratio (LLR) values.
5. The method of claim 1 , wherein instructing the memory includes instructing the memory to pass the selected partially decoded codeword(s) to the first soft output decoder.
6. The method of claim 5 , wherein:
the plurality of metrics is associated with a number of unsatisfied parity checks; and
selecting includes selecting a partially decoded codeword having the smallest number of unsatisfied parity checks.
7. The method of claim 5 , wherein:
the plurality of metrics is associated with an average of certainty values; and
selecting includes selecting a partially decoded codeword having the largest average of certainty values.
8. The method of claim 1 , wherein instructing the memory includes instructing the memory to delete the selected partially decoded codeword(s).
9. The method of claim 8 , wherein:
the plurality of metrics is associated with a number of unsatisfied parity checks; and
selecting includes selecting a partially decoded codeword having the largest number of unsatisfied parity checks.
10. The method of claim 8 , wherein:
the plurality of metrics is associated with an average of certainty values; and
selecting includes selecting a partially decoded codeword having the smallest average of certainty values.
11. A system, comprising:
a memory; and
a memory manager configured to:
obtain a plurality of metrics associated with a plurality of partially decoded codewords, wherein:
the plurality of partially decoded codewords has been processed at least once by a first soft output decoder and a second soft output decoder; and
the plurality of partially decoded codewords is stored in the memory;
determine that a utilized storage capacity of the memory has reached a threshold;
in response to the determination that the utilized storage capacity of the memory has reached the threshold, select at least one of the plurality of partially decoded codewords based at least in part on the plurality of metrics; and
instruct the memory to vacate the at least one selected codeword, wherein vacating the at least one selected codeword includes discarding the at least one selected codeword from the memory.
12. The system of claim 11 , wherein the first soft output decoder includes a soft output Viterbi algorithm (SOVA) decoder.
13. The system of claim 11 , wherein the second soft output decoder includes a low-density parity-check (LDPC) decoder.
14. The system of claim 11 , wherein the plurality of metrics is associated with one or more of the following: a number of unsatisfied parity checks, an average of certainty values, a median of certainty values, or log-likelihood ratio (LLR) values.
15. The system of claim 11 , wherein the memory manager is configured to instruct the memory including by instructing the memory to pass the selected partially decoded codeword(s) to the first soft output decoder.
16. The system of claim 15 , wherein:
the plurality of metrics is associated with a number of unsatisfied parity checks; and
the memory manager is configured to select including by selecting a partially decoded codeword having the smallest number of unsatisfied parity checks.
17. The system of claim 15 , wherein:
the plurality of metrics is associated with an average of certainty values; and
the memory manager is configured to select including by selecting a partially decoded codeword having the largest average of certainty values.
18. The system of claim 11 , wherein the memory manager is configured to instruct the memory including by instructing the memory to delete the selected partially decoded codeword(s).
19. The system of claim 18 , wherein:
the plurality of metrics is associated with a number of unsatisfied parity checks; and
the memory manager is configured to select including by selecting a partially decoded codeword having the largest number of unsatisfied parity checks.
20. The system of claim 18 , wherein:
the plurality of metrics is associated with an average of certainty values; and
the memory manager is configured to select including by selecting a partially decoded codeword having the smallest average of certainty values.
21. A computer program product, the computer program product being embodied in a non-transitory tangible computer readable storage medium and comprising computer instructions for:
obtaining a plurality of metrics associated with a plurality of partially decoded codewords, wherein:
the plurality of partially decoded codewords has been processed at least once by a first soft output decoder and a second soft output decoder; and
the plurality of partially decoded codewords is stored in a memory;
determining that a utilized storage capacity of the memory has reached a threshold;
in response to the determination that the utilized storage capacity of the memory has reached the threshold, selecting at least one of the plurality of partially decoded codewords based at least in part on the plurality of metrics; and
instructing the memory to vacate the at least one selected codeword, wherein vacating the at least one selected codeword includes discarding the at least one selected codeword from the memory.