Design of LDPC codes for adaptive OFDM modulation and coding system based on EXIT function
基于EXIT函数的自适应OFDM-LDPC调制编码方案设计

This paper proposed an adaptive channel coding and modulation scheme based on EXIT function for OFDM transmission over Rayleigh fading channel. And studied mutual information of LDPC code in Rayleigh fading channel. Mutual information of check node was got by numerical integral. It made the analysis more accurate, particularly for fading channel where the messages from check nodes were far from Gaussian at low SNR. Also studied the EXIT charts for this system and presented an adaptive OFDM-LDPC scheme with EXIT error function as cost function. Compared to traditional one, this method achieved best scheme with low complexity and had no use of getting switch threshold, This design method was suitable for high rate transmission. Finally, given simulation results and analysis based on 802.16e standard.