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/* -*- c++ -*- */
/*
* Copyright 2008,2010,2012 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 "fmdet_cf_impl.h"
#include <gnuradio/io_signature.h>
#include <gnuradio/math.h>
namespace gr {
namespace analog {
fmdet_cf::sptr
fmdet_cf::make(float samplerate, float freq_low,
float freq_high, float scl)
{
return gnuradio::get_initial_sptr
(new fmdet_cf_impl(samplerate, freq_low, freq_high, scl));
}
fmdet_cf_impl::fmdet_cf_impl(float samplerate, float freq_low,
float freq_high, float scl)
: sync_block("fmdet_cf",
io_signature::make(1, 1, sizeof(gr_complex)),
io_signature::make(1, 1, sizeof(float))),
d_S1(0.1), d_S2(0.1),
d_S3(0.1), d_S4(0.1)
{
d_freq = 0;
d_freqhi = freq_high;
d_freqlo = freq_low;
set_scale(scl);
}
fmdet_cf_impl::~fmdet_cf_impl()
{
}
void
fmdet_cf_impl::set_scale(float scl)
{
float delta = d_freqhi - d_freqlo;
d_scl = scl;
d_bias = 0.5*scl*(d_freqhi + d_freqlo) / delta;
}
void
fmdet_cf_impl::set_freq_range(float freq_low, float freq_high)
{
d_freqhi = freq_high;
d_freqlo = freq_low;
set_scale(d_scl);
}
int
fmdet_cf_impl::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];
int size = noutput_items;
gr_complex Sdot, S0;
gr_complex S1=d_S1, S2=d_S2, S3=d_S3, S4=d_S4;
while(size-- > 0) {
S0 = *iptr++;
Sdot = d_scl * (-S0 + 8.f*S1 - 8.f*S3 + 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;
}
} /* namespace analog */
} /* namespace gr */
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