该代码包括m序列产生、以及M元扩频的源程序。（M元扩频的程序，每次只跑一个信噪比下的误码率，要绘制误码率曲线，需要手动跑多个点）-The code includes m-sequence generator, as well as M-ary spread spectrum of the source. (M-ary spread spectrum program, a time to run a bit error rate signal to noise ratio under the BER curves to be drawn, you need to manually run multiple points)