|
From: | Raj Bhattacharjea |
Subject: | Re: [Discuss-gnuradio] Channel model - the identity channel |
Date: | Tue, 28 Jun 2016 22:47:43 -0400 |
Hey Raj,
> introduces a delay that can be corrected by applying the taps [0,0,0,1].
> See the attached flowgraph that subtracts the signals before and after
> the channel model; if you let taps = 1, the two signals don't cancel. If
> you use taps = [0,0,0,1], they do.
The delay you are seeing is introduced by the fractional_resapmler
inside the channel_model block. The FIR filter inside the fractional
resampler needs to build up and therefore introduces a initial delay of
three samples.
If you want to know more about the insides of the channel model I
suggest you look at the sources [0][1] yourself.
Greetings,
Andrej
[0] ./gr-channels/lib/channel_model_impl.cc
[1] ./gr-channels/lib/channel_model_impl.h
[Prev in Thread] | Current Thread | [Next in Thread] |