Reverse concatenated encoding and decoding

1. A method for receiving data, comprising:

receiving an encoded data stream; and

decoding the encoded data stream with a reverse concatenated decoder, said decoding comprising:

inner decoding the encoded stream with a soft maximum a posteriori inner decoder that uses a low-complexity linear-block code to produce an inner-decoder output stream;

outer decoding the inner-decoder output stream with an outer decoder that uses a low-density parity-check code having a girth between 6 and 8 and a column weight of 3 to produce an information stream; and

iterating extrinsic log-likelihood ratios from said outer decoding for use in subsequent inner decoding to improve decoding performance.

2. The method of claim 1 , wherein the inner decoder uses a Bose-Chaudhuri-Hocquenghem (BCH) code.

3. The method of claim 1 , wherein the inner decoder uses a Reed-Muller code.

4. The method of claim 1 , wherein decoding further comprises deinterleaving the inner-decoder output stream before outer decoding.

5. A method for transmitting data, comprising:

receiving an information stream;

encoding the information stream with a reverse concatenated encoder to enable iterated reliability reverse concatenated decoding, said encoding comprising:

outer encoding the information stream with an outer encoder that uses a low-density parity-check (LDPC) code having a girth between 6 and 8 and a column weight of 3; and

inner encoding the LDPC-encoded stream with an inner encoder that uses a low-complexity block code; and

transmitting the reverse concatenated encoded stream.

6. The method of claim 5 , wherein the inner encoder uses a Bose-Chaudhuri-Hocquenghem (BCH) code.

7. The method of claim 5 , wherein the inner encoder uses a Reed-Muller code.

8. The method of claim 5 , wherein the encoding further comprises interleaving the LDPC-encoded stream before inner encoding.

9. A receiver, comprising:

a detector configured to receive a reverse concatenated encoded signal and pass the signal to a reverse concatenated decoder; and

one or more reverse concatenated decoders configured to decode the reverse concatenated encoded signal to produce an information stream, each comprising:

a soft maximum a posteriori inner decoder configured to decode the reverse concatenated encoded signal with a low-complexity linear-block code and to produce an inner-decoder output stream; and

an outer decoder configured to decode the inner-decoder output stream using a low-density parity-check code having a girth between 6 and 8 and a column weight of 3 to produce an information stream and further configured to iterate extrinsic log-likelihood ratios to the inner decoder to improve decoding performance.

10. The receiver of claim 9 , wherein the inner decoder uses a Bose-Chaudhuri-Hocquenghem (BCH) code.

11. The receiver of claim 9 , wherein the inner decoder uses a Reed-Muller code.

12. A transmitter, comprising:

one or more reverse concatenated encoders configured to encode an information stream and produce a reverse concatenated encoded stream to enable iterated reliability reverse concatenated decoding, each comprising:

an outer encoder configured to encode an information stream using a low-density parity-check (LDPC) code having a girth between 6 and 8 and a column weight of 3; and

an inner encoder configured to encode the LDPC-encoded stream with a low-complexity linear-block code; and

one or more modulators configured to modulate the reverse concatenated encoded streams onto a carrier for transmission.

13. The transmitter of claim 12 , wherein the inner encoder uses a Bose-Chaudhuri-Hocquenghem (BCH) code.

14. The transmitter of claim 12 , wherein the inner encoder uses a Reed-Muller code.

15. The transmitter of claim 12 , wherein the one or more reverse concatenated encoders each further comprise an interleaver configured to interleave the LDPC-encoded stream and to output the interleaved stream to the inner encoder.