Evaluation of low density parity-check codes on frequency-selective fading channels

Many papers have shown that low density parity-check (LDPC) codes exhibit excellent performance in the additive white noise (AWGN) channel and flat fading channels, but their performance on frequency-selective fading channels slightly degrades. In this paper, we evaluate the performance of quasi-regular low density parity-check codes in frequency-selective fading channels based on the large area synchronization code division multiple access (LAS-CDMA) system. Simulation results show that LDPC codes outperform turbo codes at high signal-to-noise ratio (SNR) over a wild range of mobile speeds. Furthermore we simply analyze the reasons on their differences on performance, indicating that the distance spectrum plays a very important role to the performance of codes.