Re: [Discuss-gnuradio] alpha =0.001 in gr.probe_avg_mag_sqrd_cf

[Mattias Kjellsson]

On 06/03/2010 11:54 PM, Juan Quiroz wrote:
> Hi all
>
> I had a problem with tunnel.py, but changing threshold from 30dB to 50dB it was 
> solved, now I'm reading receive_path.py in carrier sensing blocks are defined 
> alpha=0.001 and thres=30 for use with gr.probe_avg_mag_sqrd_cf, please can 
> somebody tell me what is alpha value and why is set to 0.001?
>    
Alpha is the pole placement in the single pole IIR filter, used to 
filter the signal before it is compared with the threshold. Details may 
be found in 
gnuradio/gnuradio-core/src/lib/filter/gr_single_pole_iir_filter_xx.cc

Mattias