raputil.py 文件源码

def add_noise(self,Y0):
        'add noise at the given SNR, returns Y0+W,wvar'
        wvar = (la.norm(Y0)**2/Y0.size) * 10**(-self.SNR_dB/10)
        if self.cpx:
            Y =(Y0 + crandn(Y0.shape) * sqrt(wvar/2)).astype(np.complex64,copy=False)
        else:
            Y = (Y0 + np.random.normal(scale=sqrt(wvar),size=Y0.shape) ).astype(np.float32,copy=False)
        return Y,wvar