The Research On The Concatenated LDPC Coding And Space-Time Multiple Input Multiple Output System For Wireless Communications

The linear block code is called a binary low-density parity-check code and its performance is very close to the Shannon limits when combined with BP decoding algorithm. The LDPC codes are relatively easy to be defined and can outperform the turbo codes with sufficiently long block lengths. Its decoding complexity is also lower than that of turbo code. Recently, LDPC code has drawn the worldwide attentions in channel coding community due to its high performance and strong potential.The MIMO technology can increase the capacity of wireless communication greatly without occupying more additional bandwidth that is limited for wireless communications. Thus, more attention is dedicated to investigate the high-efficient signal processing and the advanced channel coding techniques within the MIMO framework to provide the high-speed and high-quality data transmission. We employ the antenna diversity techniques to reduce the influence of multipath fading in wireless communications, and thus inhance the transmission reliability. The space- time block coding takes the advantages of space and time diversities, but merely incurs the linear increment for decoding complex. The V-BLAST system uses the advanced signal detection technique and transmits the data accurately and effectively, and results in an enormous enhancement for the link capacity. However, MIMO only offers diversity gain but without coding gain. If an appropriate channel code concatenated with MIMO scheme, the concatenated space-time codes are possibly to obtain both the diversity and coding gains. Therefore, the performance of coded wireless communication system can be greatly improved.The contributions of this thesis are mainly categorized as following three aspects: (1) Research on the LDPC coding which has drawn the worldwide attentions in channel coding community. The details of the coding and decoding are introduced and the performance is investigated by theoretical analysis and numerical simulations. The factors that can impact the performance of the coded systems are studies and concluded through the simulations. (2) After the fundamantals of the advanced EGT, STBC and V-BLAST transmission techniques are briefly introduced, we extensively study coding/decoding and signal processing techniques for various MIMO systems, and performance simulation is also carried out over a Rayleigh chaneel. (3) We study the MIMO system where LDPC code is employed. The performance of the concatenated scheme is investigated by both the theoretical analysis and numerical simulations. We conclude that even if with the moderate block length and number of iterative decoding for LDPC codes we can still obtain the better performance by using the proposed approach.