在AWGN信道下BPSK调制LDPC码的误码率，以及调用函数“对数域和LDPC译码算法”，把发送的信号的矩阵为零矩阵，用MatlaB运行 -BPSK modulation in AWGN channel bit error rate of the LDPC code, and call the function "of the number of domains and LDPC decoding algorithm, the matrix of the transmitted signal