Design And Optimization Of Encoder And Decoder Of Turbo Code Based On 802.16d/e Standards

IEEE802.16d/e are broadband wireless access standard. Higher capacity, greater coverage mobility are realized by new technology (OFDM,MIMO etc.) and become an important part of 4G wireless communication standard. The thesis is about Duo-binary convolutional turbo codes (CTC) in 802.16d/e standards.This paper briefly analyzes CTC principle in 802.16d/e standards, some CTC decoding algorithms are comparatively studied, considers decoding precision and speed. One new SNR adaptive decoding algorithm is recommended in this paper. The SNR adaptive algorithm is applicable to dramatic changes in channel conditions. In low SNR, The algorithm BER is closed Log-MAP; in the high SNR, both of calculation quantity and BER are better than Log-MAP.Design CTC encoder of IEEE802.16d/e standard. In the CTC FPGA structure,the process used in achieving the pipelining structure and improve the system throughput. We propose CTC decoder SNR adaptive structure design, make constant-log-MAP algorithm and En-Max-log-MAP algorithm to effectively integrate, and give the key decoder modules. Optimization of the performance of the decoder put forward some new ideas.