程序的主要功能是做了一定范围的信噪比下，对每个信噪比：随机信号QPSK调制；

根据Alamouti方案的矩阵进行编码；发送信号经过瑞利信道和加入高斯白噪声；

接收信号采用最大比合并的方法；最后对合并信号进行最大似然判决并求误符号率。

结果表明10^-3对应大约12->13dB-Procedure main function is to do a certain range of SNR for each signal to noise ratio: random signal QPSK modulation　program in accordance with Alamouti coding matrix　send signals through Rayleigh channel and adding Gaussian white noise　received signal using maximal-ratio combining method　Finally the combined signal and the maximum likelihood decision for symbol error rate. The results showed that about 10 ^-3 corresponds to 12-> 13dB