LDPC Code Design for Joint Channel Estimation, Symbol Detection and LDPC Decoding in Time-Varing Fading Channels

• Main Author: 賴沛霓
• Other Authors: 伍紹勳
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/60649688336879216535

碩士 === 國立交通大學 === 電信工程研究所 === 98 === Without using any pilot and training symbols, a serially concatenated turbo transceiver is proposed for joint channel estimation, symbol detection and LDPC decoding in Rayleigh fading channels. In fading channels, the dependence of variable nodes in the factor graph lingers slightly according to the fading speeds. However the independence assumption is necessary for the cycle-free condition of LDPC codes. Hence we added the design criterion that the variable nodes connected to the same check node are restricted to be in different coherence intervals to meet the constraint. The performance of finite-length LDPC codes would be affected both by the number of coherence intervals and the fading speed.