Claims
- 1. A method of increasing error correction capability in an error correction system using multiple encoders and decoders wherein codewords are encoded and decoded using concatenated codes comprising multiple constituent codes in which encoded information appears in multiple codewords and where each codeword is encoded using an error correction code having an error correction capability, the method comprising the steps of:
interleaving the constituent codes in multiple dimensions in a codeword frame; sequentially encoding the constituent codes in their separate multiple dimensions employing error correction information symbols to enhance correction performance; and encoding any redundancy symbols present in constituent codes.
- 2. The method of claim 4 further comprising the steps of sequentially decoding the symbols of the constituent codes while decoding at least some of the redundancy symbols during decoding of at least one of the constituent codes.
- 3. The methods of claim 1 further comprising the step of reducing error multiplication by allowing soft decode outputs from one decoder to a next decoder.
- 4. The method of claim 1 further comprising the step of detecting for uncorrectable error patterns and thereafter correcting the code to eliminate at least some of the patterns.
- 5. The method of claim 4 further comprising the steps of sequentially decoding the symbols of the constituent codes while decoding at least some of the redundancy symbols during decoding of at least one of the constituent codes and implementing at least one final decoding pass of the constituent codes after correcting for error patterns.
- 6. The method of claim 1 wherein codewords arranged in multiple dimensions are arranged in orthogonal directions in a codeword frame, the codewords in each direction sharing symbols with codewords in other directions.
- 7. The method of claim 1 wherein the interleaving of the constituent codes in multiple dimensions comprises two directions.
- 8. The method of claim 1 wherein the constituent codes that are concatenated are an RS code and a BCH code.
- 9. A method of performing multidimensional forward error correction comprising the steps of:
interleaving constituent codes in orthogonal directions; encoding data employing error correction code information symbols comprised of data forming first and second codewords in orthogonal directions, the first and second codewords sharing at least some of the same redundancy symbols; encoding the shared redundancy symbols of the constituent codes; generating received symbols comprising in-error symbols of the first and second codewords and forming first and second received symbols sharing at least some of the redundancy symbols; decoding the first received symbols, including correcting at least some of the in-error redundancy symbols of the first received codewords shared with those of the second received codewords; and decoding the second received symbols, wherein the second received symbols include symbols corrected during the decoding of the first received symbols, including correcting at least some of the in-error redundancy symbols of the second received codeword shared with those of the first received codewords.
- 10. The method of claim 7 further comprising the step of decoding in multiple sequential passes of the first and second received symbols, each decoding pass employing symbols corrected during previous decoding passes.
- 11. The method in claim 10 wherein the multiple pass sequential passes of the first and second received symbols comprises a decoding pass sequence through a BCH decoder, a RS decoder, a BCH decoder, a RS decoder, a BCH decoder, an error pattern correction, a RS decoder, a BCH decoder, and a RS decoder.
- 12. The method in claim 11 wherein the decoding pass sequence comprises the step of re-passing the first and second received symbols of a codeword multiple times through a first and second decoder while the codeword is being assembled.
- 13. The methods of claim 7 further comprising the step of reducing error multiplication by allowing soft decode outputs from one decoder to a next decoder.
- 14. The method of claim 7 further comprising the step of detecting error patterns and thereafter correcting the code to eliminate at least some of the patterns.
- 15. The method of claim 14 further comprising the step of implementing at least one final decoding pass of the constituent codes after correcting for error patterns.
- 16. The method in claim 7 where the number of codewords undergoing error correction comprises two codewords.
- 17. The method in claim 7 wherein the constituent codes are RS and BCH codes and the RS code is correction limited to a flexibly controlled value less than t errors in any one or more passes through a RS decoder.
- 18. The method in claim 17 comprising the further step of deploying a RS and BCH code error locator polynomial to reduce miss-corrections or error multiplication when the polynomial degree does not equal the number of roots found.
- 19. The method in claim 17 where the BCH decoder provides soft decode output to the RS decoder and the RS decoder provides soft decode output to the BCH decoder to reduce miss-corrections or error multiplication.
- 20. The method of claim 7 comprising the further step of detecting uncorrectable error patterns by using the junction of the uncorrectable codewords in orthogonal directions.
- 21. The method of claim 20 further comprising the step of performing a junction detection between uncorrectable orthogonal codewords employing non-zero syndrome polynomials to indicate a presence of codeword errors.
- 22. The method of claim 20 where correction attempts on the codeword junctions is a trial and error process using a non-zero syndrome value as a fail indication of a correction attempt.
- 23. The method of claim 20 where correction attempts are performed in parallel and using a non-zero syndrome value as a fail indication of a correction attempt.
- 24. The method of claim 20 comprising the further step of performing a final stage of constituent code decoding of codewords comprising a BCH decoder and a RS decoder.
- 25. The method of claim 24 wherein the last decoding pass is with an RS decoder.
- 26. An error correction system for increasing error correction capability comprising:
multiple encoders for encoding symbols forming separate multiple codewords in orthogonal directions; said multiple codewords sharing at least some redundancy symbols which are also encoded as redundancy symbols; means for generating received symbols comprising in-error symbols of the first and second code words and forming first and second received symbols sharing at least some of the redundancy symbols; a first decoder for decoding the first received symbols, including correcting at least some of the in-error redundancy symbols of the first received codewords shared with those of the second received codewords; and a second decoder for decoding the second received symbols, wherein the second received symbols include symbols corrected during the decoding of the first received symbols, including correcting at least some of the in-error redundancy symbols of the second received codeword shared with those of the first received codewords.
- 27. The error correction system of claim 26 further comprising means to re-pass the first and second received symbols of an instant codeword multiple times through the first and second decoders while the next codeword is being assembled.
- 28. The error correction system of claim 26 wherein the first and second decoders comprise a BCH decoder and a RS decoder.
- 29. The error correction system of claim 26 further comprising a plurality of decoders for sequential passing of said first and second received symbols.
- 30. The error correction system of claim 29 wherein the sequence of decoders comprises pairs of BCH and RS decoders wherein a last decoder is an RS decoder.
BACKGROUND OF THE INVENTION
[0001] This application claims priority of U.S. provisional application, Serial No. 60/332,022, filed Nov. 21, 2001, which application is incorporated herein by its reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60332022 |
Nov 2001 |
US |