Theory Research And Decoder Simulation Platform Realization Of LDPC Codes

The outstanding performance of LDPC codes and good prospects of reliable transmission of information in the application(for example, Optical communication,satellite communication, deep space communications, fourth-generation mobile communication systems, etc.), has attracted the world academia and the IT industry attentions and becomes the most notable areas of research hot spots in today's channel coding. In recent years the international community on the theoretical study LDPC codes have made important progress in the application of basic and engineering applications and VLSI (very large scale integrated circuits) Implementation of research carried out in all directions.This study focuses on the LDPC girth calibration, good LDPC code searching and the achievement of LDPC BP algorithm simulation platform, we mainly do girth calibration algorithm and BP algorithm of theoretical study and Coding, lay a good foundation for for the future of the DSP realization. Including work in the following areas:First, introduce the most important factor of LDPC perfermance. On the basis of the girth distribution, this paper present a way of algorithm based on graph theory for counting the number of girth, and analyze the shape of short girth in the LDPC check matrix (4-girth, 6-girth) , then presents a new Implementation way of the girth calibration based on graph theory, and implemented by C. Using this algorithm, we can calculate the number of short cycles in the check matrix. We can also use the algorithm for finding the good Quasi-Cyclic (QC) Code with large girth.Second, design BP algorithm simulation platform of LDPC code. Introduce the iuput matrix format in simulation platform and the configuration file format. Design the various modules in details and implement the simulation platform by C language, then give the simulation result.