Designing Iterative Decoding Schemes with the Extrinsic Information Transfer Chart 论文

摘要

Since the discovery of parallel concatenated (turbo) codes, iterative decoding has become a vital field of research in digital communications. Applications of the turbo princi- ple to many detection and decoding problems have been found. While most studies have focused on designing code concate- nations with respect to maximum likelihood decoding perfor- mance, the convergence properties of iterative decoding schemes have gained a considerable amount of interest just recently. In this paper we use the extrinsic information transfer chart (EXIT chart) to illuminate the convergence properties of bit- interleaved coded modulation, equalization, and serially con- catenated binary codes. The EXIT chart leads to new design ideas like inner and outer doping, facilitating the construction of code concatenations with iterative decoders operating close to the capacity limit.