Channel Coding Technology Research And Its Application In MIMO-OFDM

With the development of the modern technology and the increasing needs to the communication, the communication technology has been changed greatly. At present, the wireless communication is in the 3rd generation, and gradually evolving to the 4th generation. MIMO-OFDM is one of the elite technologies in the B3G. It is possible to achieve high speed data transmission by making use of MIMO-OFDM technology, and its ability of anti-interference is powerful. In the communication system, advanced channel coding method is also very important. Turbo code and Low Density of Parity Code (LDPC) are two of the high performance channel coding methods, and lately have becoming the hot spots of research that have being concerned in the field of channel coding. These two methods of channel coding and their applications in MIMO-OFDM system are researched to investigate their performances in this paper.Firstly, the models of OFDM and MIMO are researched separately, and the characteristics and performances of MIMO-OFDM system are discussed. The simulation platform is illustrated in some cases.Secondly, the coding and decoding methods of Turbo code and LDPC based on finite geometries are addressed. Construct the check matrix of EG-LDPC using the finite geometries method and simulate its performance. Log-MAP decoding algorithm is discussed and the correction function of Log-MAP algorithm is improved using mathematical expansion, it reduces the complexity of the algorithm and makes it easier to achieve after the transformation. The simulation result shows that the performance of the improved method is better than the Max-Log-MAP.Thirdly, Turbo code and finite geometries LDPC are used in the MIMO-OFDM system, the simulation results indicate that the performance of the BER is improved greatly by these two channel coding methods, and in the wake of the increasing iterations, the BER reduces.Finally, the construction and characteristics of serial concatenate LDPC-Turbo coding system is discussed and used in the MIMO-OFDM system. The simulation result shows that, in some aspect of the performances, the concatenation coding scheme is better than the original EG-LDPC and Turbo code.