中文说明：VSB调制及解调用matlab产生一个频率分别为5Hz、5/2 Hz的余弦和正弦叠加信号作为信源，两个频率分量功率相同，总信号功率为2，设载波频率为20Hz，试画出：l 残留边带为的VSB调制信号时域波形；l 采用相干解调后的VSB信号波形；l 调制信号的功率谱密度；l 在接收端带通后加上窄带高斯噪声，单边功率谱密度，重新解调。
English Description：
VSB modulation and demodulation uses MATLAB to generate a cosine and sine superposition signal with the frequency of 5Hz and 5 / 2Hz as the signal source. The power of the two frequency components is the same, the total signal power is 2, and the carrier frequency is 20Hz. Try to draw: L & nbsp; time domain waveform of VSB modulation signal with residual sideband; L & nbsp; VSB signal waveform with coherent demodulation; L & nbsp; The power spectral density of the modulated signal; L & nbsp; after the bandpass of the receiver, the narrowband Gaussian noise is added, and the single side power spectral density is demodulated again.