script to generate swept signal for tx testing

git-svn-id: https://svn.code.sf.net/p/freetel/code@1159 01035d8c-6547-0410-b346-abe4f91aad63

diff --git a/codec2-dev/octave/fdmdv_sweep.m b/codec2-dev/octave/fdmdv_sweep.m
new file mode 100644 (file)
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+++ b/codec2-dev/octave/fdmdv_sweep.m
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+% fdmdv_sweep.m
+% David Rowe Feb 2013
+% Produces a raw file that sweeps between 1000 and 2000 Hz to test freq
+% response of transmitters.
+
+secs=10;
+fmin=1000;
+fmax=2000;
+Fs=8000;
+rms = 4200;  % roughly RMS value of fdmdv signal
+amp = sqrt(2)*rms;
+nsamples=Fs*secs;
+theta = 0;
+s=zeros(1,nsamples);
+
+for i=1:nsamples
+  f(i) = fmin + i*(fmax-fmin)/nsamples;
+  w = 2*pi*f(i)/Fs;  
+  theta += w;
+  theta -= 2*pi*floor(theta/(2*pi));
+  s(i) = amp*cos(theta);  
+end
+
+figure(1)
+clf
+plot(s(1:100));
+fout = fopen("1k_2k_sweep.raw", "wb");
+fwrite(fout, s, "short");
+fclose(fout);
+