Matlab产生正弦波、均匀白噪声、高斯白噪声，并将两种噪声叠加到正弦波上。并给出自相关和功率谱密度波形(Matlab produces sine wave, uniform white noise, Gauss white noise, and superimposes two kinds of noise on the sine wave. And give self correlation and power spectral density waveforms)