In my opinion,the noise_amp should be the standard deviation,not the variance.& the normalization may be wrong

[yjyddq]

The document in gnuradio.channels.dynamic_channel_model indicates that the -noise_amp – Specifies the standard deviation of the AWGN process .
So, I think there should be noise_amp = np.sqrt(10**(- snr/10)), original code is the variance.

Besides, the Normalization of the energy may be the energy=np.sqrt(np.sum(np.abs(sample_vector)**2)),sample_vector = sample_vector / energy, rather than the following form, the former formula can promise after be normalized the total energy of a complex vector equals to one.