Method and apparatus for encoding and decoding a turbo code in an integrated modem system

• Main Authors: Stephen, Karen J, Lam, Hon W, Cromwell, Jonathan
• Format: Patent
• Language: English
• Published: 19.11.2002

1. Field of the Invention The present invention is a method and apparatus for encoding and decoding a turbo code. In the encoder, an interleaver interleaves and delays a block of input bits to generate interleaved input bits and delayed input bits. A first encoder generates a first, second, and third encoded bits. A second encoder generates a fourth encoded bit. A symbol generator generates a plurality of symbols which correspond to the input bits. In a decoder, a sync search engine detects a synchronizing pattern and extracts symbols from the encoded bits. An input buffer is coupled to the sync search engine to store the extracted symbols. A first soft-in-soft-out (SISO) is coupled to the input buffer to generate a first soft decision set based on the extracted symbols. An interleaver is coupled to the SISOto interleave the first soft decision set. A second soft-in-soft-out (SISO) is coupled to the input buffer and the interleaver to generate a second soft decision set. A de-interleaver is coupled to the SISOto de-interleave the second soft decision set. An adder is coupled to the SISOand the de-interleaver to generate a hard decision set.