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/* -*- c++ -*- */
/*
* Copyright 2004,2012 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
*/
#ifndef INCLUDED_ANALOG_FREQUENCY_MODULATOR_FC_H
#define INCLUDED_ANALOG_FREQUENCY_MODULATOR_FC_H
#include <gnuradio/analog/api.h>
#include <gnuradio/sync_block.h>
namespace gr {
namespace analog {
/*!
* \brief Frequency modulator block
* \ingroup modulators_blk
*
* \details
* float input; complex baseband output
*
* Takes a real, baseband signal (x_m[n]) and output a frequency
* modulated signal (y[n]) according to:
*
* \f[
* y[n] = exp (j 2 \pi \frac{f_{\Delta}}{f_s} \sum{x[n]})
* \f]
*
* Where x[n] is the input sample at time n and \f$ f_{\Delta} \f$
* is the frequency deviation. Common values for \f$ f_{\Delta}
* \f$ are 5 kHz for narrowband FM channels such as for voice
* systems and 75 KHz for wideband FM, like audio broadcast FM
* stations.
*
* In this block, the input argument is \p sensitivity, not the
* frequency deviation. The sensitivity specifies how much the
* phase changes based on the new input sample. Given a maximum
* deviation, \f$ f_{\Delta} \f$, and sample rate \f$f_s\f$, the
* sensitivity is defined as:
*
* \f[
* k = 2 \pi \frac{f_{\Delta}}{f_s}
* \f]
*/
class ANALOG_API frequency_modulator_fc : virtual public sync_block
{
public:
// gr::analog::frequency_modulator_fc::sptr
typedef boost::shared_ptr<frequency_modulator_fc> sptr;
/*!
* Build a frequency modulator block.
*
* \param sensitivity radians/sample = amplitude * sensitivity
*/
static sptr make(float sensitivity);
virtual void set_sensitivity(float sens) = 0;
virtual float sensitivity() const = 0;
};
} /* namespace analog */
} /* namespace gr */
#endif /* INCLUDED_ANALOG_FREQUENCY_MODULATOR_FC_H */
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