GF(2p)LDPC编码的相位调制OFDM系统在瑞利衰落信道的性能

OFDM是一项能有效对抗高速无线通信中多径衰落的关键技术，为了进一步提高OFDM系统的误码性能，许多信道编码技术已被应用于OFDM系统中，二元域LDPC码以其近香农限的误码性能和较低的译码复杂度成为研究的热点。在AWGN信道下，多元域LDPC码比等效码长的二元域LDPC码有更好的纠错性能。本文提出了一种将多元域LDPC码经过MPSK调制后用于OFDM系统的新方法。仿真结果表明，在多径衰落信道下，通过合理选择多元LDPC码域的阶数和调制的方法，多元域LDPC编码的高阶调制OFDM系统比等效码长的二元域LDPC编码OFDM系统具有更好的性能，并且由于采用了多元域LDPC的快速BP译码，译码复杂度只是稍有增加。

Performance of GF(2p)LDPC coded OFDM using MPSK in Rayleigh fading environment

Orthogonal Frequency Division Multiplexing(OFDM)is a very attractive technique for high-bit-rate wireless communication in a multi-path fading environment.Many channel coding techniques have been applied in OFDM systems to improve system error rate performance.Low-Density Parity-Check(LDPC)codes have received a lot of attention because of near-Shannon performance and low decoding computation complexity.On AWGN channel,GF(2p)LDPC codes outperform equivalent code length GF(2)LDPC codes.In this paper,a novel GF(2p)LDPC coded OFDM system using MPSK is proposed.Simulations show that this system achieves better error rate performance than GF(2)LDPC coded OFDM system using MPSK both on AWGN channel and multi-path fading channel.Moreover,a fast belief propagation(BP)decoding algorithm is adopted in this system to reduce the decoding computation complexity.