Code Optimization for Lossless Turbo Source Coding

A novel source coding scheme based on turbo codes was presented in [1]. Lossless data compression is thereby achieved by puncturing data encoded with a turbo code while checking the integrity of the reconstructed information during compression. In this paper we apply code optimization tools to serially concatenated turbo source codes. The goal of the optimization is to minimize the area of the tunnel in the modified EXIT chart as it is proportional to the gap between source coding rate and entropy. We show that compression rates close to the Shannon limit can be obtained by irregular repeat accumulate codes.