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/* -*- c++ -*- */
/*
* Copyright 2006,2012 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.
*/
#ifndef INCLUDED_ANALOG_AGC_H
#define INCLUDED_ANALOG_AGC_H
#include <gnuradio/analog/api.h>
#include <gnuradio/gr_complex.h>
#include <cmath>
namespace gr {
namespace analog {
namespace kernel {
/*!
* \brief high performance Automatic Gain Control class for complex signals.
* \ingroup level_controllers_blk
*
* \details
* For Power the absolute value of the complex number is used.
*/
class ANALOG_API agc_cc
{
public:
/*!
* Construct a complex value AGC loop implementation object.
*
* \param rate the update rate of the loop.
* \param reference reference value to adjust signal power to.
* \param gain initial gain value.
* \param max_gain maximum gain value (0 for unlimited).
*/
agc_cc(float rate = 1e-4, float reference = 1.0,
float gain = 1.0, float max_gain = 0.0)
: _rate(rate), _reference(reference),
_gain(gain), _max_gain(max_gain) {};
virtual ~agc_cc() {};
float rate() const { return _rate; }
float reference() const { return _reference; }
float gain() const { return _gain; }
float max_gain() const { return _max_gain; }
void set_rate(float rate) { _rate = rate; }
void set_reference(float reference) { _reference = reference; }
void set_gain(float gain) { _gain = gain; }
void set_max_gain(float max_gain) { _max_gain = max_gain; }
gr_complex scale(gr_complex input)
{
gr_complex output = input * _gain;
_gain += _rate * (_reference - std::sqrt(output.real()*output.real() +
output.imag()*output.imag()));
if(_max_gain > 0.0 && _gain > _max_gain) {
_gain = _max_gain;
}
return output;
}
void scaleN(gr_complex output[], const gr_complex input[], unsigned n)
{
for(unsigned i = 0; i < n; i++) {
output[i] = scale (input[i]);
}
}
protected:
float _rate; // adjustment rate
float _reference; // reference value
float _gain; // current gain
float _max_gain; // max allowable gain
};
/*!
* \brief high performance Automatic Gain Control class for float signals.
*
* Power is approximated by absolute value
*/
class ANALOG_API agc_ff
{
public:
/*!
* Construct a floating point value AGC loop implementation object.
*
* \param rate the update rate of the loop.
* \param reference reference value to adjust signal power to.
* \param gain initial gain value.
* \param max_gain maximum gain value (0 for unlimited).
*/
agc_ff(float rate = 1e-4, float reference = 1.0,
float gain = 1.0, float max_gain = 0.0)
: _rate(rate), _reference(reference), _gain(gain),
_max_gain(max_gain) {};
~agc_ff() {};
float rate () const { return _rate; }
float reference () const { return _reference; }
float gain () const { return _gain; }
float max_gain () const { return _max_gain; }
void set_rate (float rate) { _rate = rate; }
void set_reference (float reference) { _reference = reference; }
void set_gain (float gain) { _gain = gain; }
void set_max_gain (float max_gain) { _max_gain = max_gain; }
float scale (float input)
{
float output = input * _gain;
_gain += (_reference - fabsf (output)) * _rate;
if(_max_gain > 0.0 && _gain > _max_gain)
_gain = _max_gain;
return output;
}
void scaleN(float output[], const float input[], unsigned n)
{
for(unsigned i = 0; i < n; i++)
output[i] = scale (input[i]);
}
protected:
float _rate; // adjustment rate
float _reference; // reference value
float _gain; // current gain
float _max_gain; // maximum gain
};
} /* namespace kernel */
} /* namespace analog */
} /* namespace gr */
#endif /* INCLUDED_ANALOG_AGC_H */