说明：  已调信号经过AWGN信道，解调器输入信噪比为100，绘制加性噪声后的接受信号时间波形，频谱，解调信号的时域波形。
(Modulated signal through the input SNR AWGN channel, a demodulator 100, drawing the acceptance signal after the time waveform of additive noise, the spectrum, the demodulated signal of the time domain waveform.)