Principle And Application Of Ldpc Codes And Decoding

The future mobile communication system is designed to be much more powerful than the third generation one. It will work at a data rate of 100Mbps over a 20M hertz channel band width. So it is a huge challenge to solve the inconsistency between the reliability and the super-high spectrum efficiency. The researchers on the channel coding theory are given a good opportunity again. In the second and third generation mobile communication system, convolution code and turbo code made a huge success, and can they be winner again? Many researchers are not very optimistic: the convolution code is not powerful enough to ensure the reliability while the turbo code decoder can not support the super-high data rate. The renaissance of low-density parity-check (LDPC) code offered a new choice. LDPC code was invented by Dr.Gallager in the year of 1962, but its importance was not realized until the end of the last century. It can achieve information rate very close to Shannon limit, with a decoder which is of linear time complexity versus block length and can support the throughput tens times of turbo code decoder. With the success in the fields of space communication, fiber communication and storage industry, LDPC is becoming a powerful competitor. In this thesis, the basis of communication and channel coding theory is introduced briefly. After the definition of LDPC code, the encoding and decoding algorithms, also the performance analysis of decoding algorithms, are studied, with a theoretic analysis and an experimental simulation. At last, this thesis researches the application of LDPC code in the beyond 3G wireless communication system, including the code design, the software encoder/decoder, and the efficient combination with other technologies. With the results of a huge number of simulations, we show that LDPC code can perform very well in B3G systems.