3 * Copyright 2006 Free Software Foundation, Inc.
5 * This file is part of GNU Radio
7 * GNU Radio is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3, or (at your option)
12 * GNU Radio is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with GNU Radio; see the file COPYING. If not, write to
19 * the Free Software Foundation, Inc., 51 Franklin Street,
20 * Boston, MA 02110-1301, USA.
23 #ifndef INCLUDED_GR_PWR_SQUELCH_FF_H
24 #define INCLUDED_GR_PWR_SQUELCH_FF_H
27 #include <gr_squelch_base_ff.h>
28 #include <gr_single_pole_iir.h>
30 class gr_pwr_squelch_ff;
31 typedef boost::shared_ptr<gr_pwr_squelch_ff> gr_pwr_squelch_ff_sptr;
33 gr_pwr_squelch_ff_sptr
34 gr_make_pwr_squelch_ff(double db, double alpha = 0.0001, int ramp=0, bool gate=false);
37 * \brief gate or zero output when input power below threshold
40 class gr_pwr_squelch_ff : public gr_squelch_base_ff
45 gr_single_pole_iir<double,double,double> d_iir;
47 friend gr_pwr_squelch_ff_sptr gr_make_pwr_squelch_ff(double db, double alpha, int ramp, bool gate);
48 gr_pwr_squelch_ff(double db, double alpha, int ramp, bool gate);
51 virtual void update_state(const float &in);
52 virtual bool mute() const { return d_pwr < d_threshold; }
55 std::vector<float> squelch_range() const;
57 double threshold() const { return 10*log10(d_threshold); }
58 void set_threshold(double db) { d_threshold = std::pow(10.0, db/10); }
59 void set_alpha(double alpha) { d_iir.set_taps(alpha); }
62 #endif /* INCLUDED_GR_PWR_SQUELCH_FF_H */