说明：  利用matlab对am，dsb，ssb，ask，fsk，bpsk信号进行正交调制解调仿真，并在不同信噪比条件下对其数字信号进行了误码率的计算。
(Using matlab to am, dsb, ssb, ask, fsk, bpsk orthogonal signal modulation and demodulation simulation, and signal to noise ratio in different conditions of its digital signal to the bit error rate calculations.)