Granted Patent B2

US 8,065,596 · App. 12/048,623 · Granted Nov 22, 2011

Abstract

Claims (55)

1. A system comprising:

a first component that decodes an input bit of data transmission stream;

a second component that de-interleaves on an output of said first component;

a third component that decodes an output of said second component;

a fourth component that interleaves an output of said third component in a feedback loop to said first component;

a fifth component adapted to:

calculate an initial branch metric associated with a received symbol of said input bit of a data transmission stream; and

calculate an additional weight parameter for said received symbol based only on extrinsic hard information; and

a sixth component adapted to compute a revised branch metric by combining said initial branch metric and said additional weight parameter.

2. The system of claim 1 , wherein said extrinsic hard information is based on output of a RS decoder.

3. The system of claim 1 , wherein said extrinsic hard information is based on specific known information transmitted.

4. The system of claim 1 , wherein said extrinsic hard information comprises information that said input bit transmits from time n to time (n+1) and equals 1.

5. The system of claim 1 , wherein said extrinsic hard information comprises information that said input bit transmits from time n to time (n+1) and equals 0.

6. The system of claim 1 , wherein said extrinsic hard information comprises information that said input bit transmits from time n to time (n+1) and is unknown.

7. The system of claim 1 , wherein said additional weight parameter comprises one of:

a positive value when said input bit of a data transmission stream matches with said extrinsic hard information;

a non-positive value when said input bit of a data transmission stream does not match with said extrinsic hard information; and

a non-positive value when said extrinsic hard information is not determined.

8. A method of decoding of an information channel in an orthogonal frequency division multiplexing (OFDM) receiver on an input bit stream, said method comprising:

using a Viterbi decoder to decode said input bit stream;

using a de-interleaver to de-interleave on an output of said Viterbi decoder;

using a hard-decision Reed-Solomon (RS) decoder to decode an output of said de-interleaver;

using an interleaver to interleave an output of the RS decoder in a feedback loop to said Viterbi decoder;

calculating an initial branch metric associated with a received symbol of an input bit of a data transmission stream;

calculating an additional weight parameter for said received symbol based only on extrinsic hard information; and

computing a revised branch metric by combining said initial branch metric and said additional weight parameter.

9. The method of claim 8 , wherein said extrinsic hard information is based on output of said RS decoder.

10. The method of claim 8 , wherein said extrinsic hard information is based on specific known information transmitted.

11. The method of claim 8 , wherein said extrinsic hard information comprises information that said input bit transmits from time n to time (n+1) and equals 1.

12. The method of claim 8 , wherein said extrinsic hard information comprises information that said input bit transmits from time n to time (n+1) and equals 0.

13. The method of claim 8 , wherein said extrinsic hard information comprises information that said input bit transmits from time n to time (n+1) and is unknown.

14. The method of claim 8 , wherein said additional weight parameter comprises one of:

a positive value when said input bit of a data transmission stream matches with said extrinsic hard information;

a non-positive value when said input bit of a data transmission stream does not match with said extrinsic hard information; and

a non-positive value when said extrinsic hard information is not determined.

15. A system to perform decoding of an information channel in an orthogonal frequency division multiplexing (OFDM) receiver on an input bit stream, said system comprising:

a Viterbi decoder adapted to decode said input bit stream;

a de-interleaver adapted to perform de-interleaving on an output of said Viterbi decoder;

a hard-decision Reed-Solomon (RS) decoder adapted to decode an output of said de-interleaver; and

an interleaver adapted to interleave an output of the RS decoder in a feedback loop to said Viterbi decoder,

wherein said Viterbi decoder comprises a branch metric unit comprising:

a calculator adapted to:

calculate an initial branch metric associated with a received symbol of an input bit of a data transmission stream; and

calculate an additional weight parameter for said received symbol based only on extrinsic hard information; and

a processor adapted to compute a revised branch metric by combining said initial branch metric and said additional weight parameter.

16. The system of claim 15 , wherein said extrinsic hard information is based on output of a RS decoder.

17. The system of claim 15 , wherein said extrinsic hard information is based on specific known information transmitted.

18. The system of claim 15 , wherein said extrinsic hard information comprises information that said input bit transmits from time n to time (n+1) and said input bit information equals one of:

zero;

one; and

unknown.

19. The system of claim 15 , wherein said additional weight parameter comprises a positive value when said input bit of a data transmission stream matches with said extrinsic hard information.

20. The system of claim 15 , wherein said additional weight parameter comprises one of:

a non-positive value when said input bit of a data transmission stream does not match with said extrinsic hard information; and

a non-positive value when said extrinsic hard information is not determined.

Assignments (23)