RE: [Discuss-gnuradio] Matlab interface for GNURadio Tunnel.py example

[Tom Rondeau]

> -----Original Message-----
> From: address@hidden [mailto:discuss-
> 
> Hi Eric,
> 
> I am designing a matlab guide interface to run the tunnel example and if
> the
> log option is selected, I am planning to throw up another GUI with the
> plots
> of the logged data.
> 
> My question at this point is, what kind of plots can be made out of the
> data
> captured. Just to get a feel, I tried just a plain "plot(data)", and
> couldn't make much sense out of the resultant plot ... I am not sure as to
> what someone would look for in the plotted data.
> I am not very familiar with the filters, fmmod, fmdemod etc outputs. So, I
> am not sure what representation is used or is going to be useful.
> 
> Appreciate any guidance in this area.
> 
> Thanks,
> Naveen

Naveen,
As you seem to have found out, the --log option dumps a lot of data to
files. There is pretty much one output file for every part of the receiver
so you can get graphs post AGC, synchronization, decoding, demodulation,
etc.

Most of these are complex values, so read them in with 
dat = read_complex_binary(filename, size)

You'll need a time base, but for ease, I often just use x=1:length(dat).
Plot the info with plot(x, real(dat), x, imag(dat)) to plot the real and
imaginary parts of the data on the same graph.

For constellation plots, take the output of the synchronizer (before the
sampler) and plot I vs. Q as plot(real(dat), imag(dat)).

Tom