Abstract:

To design channel codes with linear encoding/decoding complexity and performance approaching the Shannon limit, a kind of serial concatenated codes, termed generalized crossover product accumulate (GCPA) codes, is proposed. The outer code of GCPA codes is constructed by introducing a crossover structure into parallelconcatenated single parity-check codes and an accumulator is used as the inner code. Extrinsic information transfer (EXIT) charts are used to design GCPA codes and a design example of GCPA codes is given. Simulations show that the example has linear encoding/decoding complexity and a convergence threshold about 0.32 dB from the Shannon limit.