gr_pwr_squelch_ff.cc

这是用python语言写的一个数字广播的信号处理工具包。利用它

/* -*- c++ -*- */
/*
 * Copyright 2004,2006 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_pwr_squelch_ff.h>

gr_pwr_squelch_ff_sptr
gr_make_pwr_squelch_ff(double threshold, double alpha, int ramp, bool gate)
{
  return gr_pwr_squelch_ff_sptr(new gr_pwr_squelch_ff(threshold, alpha, ramp, gate));
}

gr_pwr_squelch_ff::gr_pwr_squelch_ff(double threshold, double alpha, int ramp, bool gate) : 
	gr_squelch_base_ff("pwr_squelch_ff", ramp, gate),
	d_iir(alpha)
{
  set_threshold(threshold);
}

std::vector<float> gr_pwr_squelch_ff::squelch_range() const
{
  std::vector<float> r(3);
  r[0] = -50.0;				// min	FIXME
  r[1] = +50.0;				// max	FIXME
  r[2] = (r[1] - r[0]) / 100;		// step size

  return r;
}

void gr_pwr_squelch_ff::update_state(const float &in)
{
  d_pwr = d_iir.filter(in*in);
}