Matching Criterion Between Source Statistics and Source Coding Rate

Joint source–channel coding (JSCC) based on double protograph low-density parity-check (DP-LDPC) codes has been shown to be a good solution for wireless communications. However, the premature error floor region of the DP-LDPC codes usually does not meet the bit-error-rate requirements. In this letter, we provide a matching criterion between the source statistics and the source coding rate using a novel protograph extrinsic information transfer (PEXIT) algorithm with a new decoding threshold. The resulting matching criterion helps predict the error floor region performance and give directions for source coding rate designs.