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/* -*- c++ -*- */
/*
* Copyright 2008,2010 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
* GNU Radio is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gr_fmdet_cf.h>
#include <gr_io_signature.h>
#include <math.h>
#include <gr_math.h>
#define M_TWOPI (2*M_PI)
gr_fmdet_cf_sptr
gr_make_fmdet_cf (float samplerate, float freq_low, float freq_high, float scl)
{
return gnuradio::get_initial_sptr(new gr_fmdet_cf (samplerate, freq_low, freq_high, scl));
}
gr_fmdet_cf::gr_fmdet_cf (float samplerate, float freq_low, float freq_high, float scl)
: gr_sync_block ("fmdet_cf",
gr_make_io_signature (1, 1, sizeof (gr_complex)),
gr_make_io_signature (1, 1, sizeof (float))),
d_S1(0.1),d_S2(0.1),
d_S3(0.1),d_S4(0.1)
{
const float h[]={0.003118678733, -0.012139843428, 0.027270898036, -0.051318579352,
0.090406910552, -0.162926865366, 0.361885392563, 0.000000000000,
-0.361885392563, 0.162926865366, -0.090406910552, 0.051318579352,
-0.027270898036, 0.012139843428, -0.003118678733};
float delta;
std::vector<float> taps(15);
d_freqhi = freq_high;
d_freqlo = freq_low;
delta = (d_freqhi - d_freqlo);
d_scl = scl;
d_bias = 0.5*scl*(d_freqhi+d_freqlo)/delta;
for (int i=0;i<15;i++) taps[i] = h[i];
// d_filter = gr_fir_util::create_gr_fir_ccf(taps);
}
int
gr_fmdet_cf::work (int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
const gr_complex *iptr = (gr_complex *) input_items[0];
float *optr = (float *) output_items[0];
// const gr_complex *scaleiptr = (gr_complex *) input_items[0];
int size = noutput_items;
gr_complex Sdot,S0,S1=d_S1,S2=d_S2,S3=d_S3,S4=d_S4;
float d_8 = 8.0;
while (size-- > 0) {
S0=*iptr++;
Sdot = d_scl * (-S0+d_8*S1-d_8*S1+S4);
d_freq = (S2.real()*Sdot.imag()-S2.imag()*Sdot.real())/
(S2.real()*S2.real()+S2.imag()*S2.imag());
S4=S3;
S3=S2;
S2=S1;
S1=S0;
*optr++ = d_freq-d_bias;
}
d_S1=S1;
d_S2=S2;
d_S3=S3;
d_S4=S4;
return noutput_items;
}
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