中文说明： 共有三个文件：gsbz文件根据输入信号和信噪比SNR，使用randn产生相应的白噪声；noisegen文件是根据输入信号和信噪比，使用randn产生均值为0的相应白噪声；Test_AWGN_FUNC文件使用MATLAB自带的AWGN函数，添加指定信噪比的噪声，添加完成后进行了SNR信噪比验证，确定SNR添加正确。
English Description：
&There are three files: gsbz file uses randn to generate the corresponding white noise according to the input signal and SNR; noise file uses randn to generate the corresponding white noise with an average value of 0 according to the input signal and SNR; test_ AWGN_ The func file uses the AWGN function of MATLAB to add the noise with the specified signal-to-noise ratio. After adding, the SNR is verified to make sure that the SNR is added correctly.