Research On Turbo Codes And Its Correlated Techniques

As a near Shannon error correction code, the turbo code has received great attention due to its wonderful performance, and has been a research hot spot since it was proposed. Although until now, research on the turbo codes, either theoretical or practical, has been developing rapidly, its encoding mechanism, iterative decoding algorithm improvement and practical application, are still under concern. During the recent 10 years, three international conferences have been held in year 97, 00, 03 separately, to discuss its theory, techniques and applications, and the forthcoming symposium on the turbo codes will be held in 2006.The near Shannon performance of the turbo code is mainly due to its iterative decoding, and its iterative principle also provides a new idea to solve some other technique problems in communication systems. In this paper, through the combination with several concrete research subjects, we mainly discuss the interleaver design for turbo encoder, time delay problem of turbo decoding and applications of the turbo code etc..The research work of this paper mainly includes the following four parts:1. Through the analysis of the basic characteristics of interleaver in turbo codes and the influence of interleaver structure on its performance, and based on the design principle of improving its distance spectrum and iterative decoding suitability, an optimized interleaver scheme is proposed. Simulation result shows the proposed interleaver has a good performance.2. From the point of improving decoding speed of the turbo codes, encoding and decoding schemes with detection function are explored. This method makes use of ideas from the parity check codes used in communication systems to combine the detection with turbo decoding by inserting some parity bits when encoding, and thus the decoding speed is improved through the reduction of the...