[Discuss-gnuradio] Problems in AM Demodulation

[Kiran N]

Hello everyone. I am working on Amplitude demodulation. I am using the attached python code. I have some doubts as to why particular frequencies are chosen. Firstly, in the code

 

channel_coeffs = gr.firdes.low_pass ( 1.0, if_rate, 8000, 1000, gr.firdes.WIN_HANN)

 

Why a cut off frequency of 8000Hz is chosen?

Any Particular reason why a transition bandwidth of 1000Hz is chosen?

 

Secondly,

volumecontrol = gr.multiply_const_ff (.003)

 

Why are we multiplying by a factor of 0.003?

 

Thirdly,

    audio_coeffs = gr.firdes.low_pass (1.0, demod_rate, 9e3, 4e3, gr.firdes.WIN_HANN)

 

Why a cut off frequency of 9000Hz is chosen?

Any Particular reason why a transition bandwidth of 4000Hz is chosen?

 

Thanks in advance..

 

am_demod.py
Description: Text document