介绍了低密度校验码LDPC码的和乘积Sum-Product译码算法,并对AWGN和瑞利信道下的性能进行了仿真(VC++)。在AWGN信道下,通过码长和迭代次数对误码性能的影响的仿真比较表明,码长越长,迭代次数越大,误码性能越好。在瑞利信道下,仿真表明LDPC码同样具有很好的误码性能,未知信道信息时的误码性能要比已知信道信息时差。 The Sum-Product decoding algorithm of sum-product of low density parity check codes (LDPC codes) is introduced, and the performance under AWGN and Rayleigh channels is simulated (VC ++). Under AWGN channel, the simulation of the effect of code length and number of iterations on error performance shows that the longer the code length, the larger the iteration number, the better the error performance. Under the Rayleigh channel, the simulation shows that the LDPC code also has good error performance. The error performance of the unknown channel information is worse than the known channel information.