GNU Radio 3.6.3.1 C++ API
gr_pwr_squelch_cc.h
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1 /* -*- c++ -*- */
2 /*
3  * Copyright 2006 Free Software Foundation, Inc.
4  *
5  * This file is part of GNU Radio
6  *
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)
10  * any later version.
11  *
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.
16  *
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,
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21  */
22 
23 #ifndef INCLUDED_GR_PWR_SQUELCH_CC_H
24 #define INCLUDED_GR_PWR_SQUELCH_CC_H
25 
26 #include <gr_core_api.h>
27 #include <cmath>
28 #include <gr_squelch_base_cc.h>
29 #include <gr_single_pole_iir.h>
30 
31 class gr_pwr_squelch_cc;
33 
35 gr_make_pwr_squelch_cc(double db, double alpha = 0.0001, int ramp=0, bool gate=false);
36 
37 /*!
38  * \brief gate or zero output when input power below threshold
39  * \ingroup level_blk
40  */
42 {
43 private:
44  double d_threshold;
45  double d_pwr;
47 
48  friend GR_CORE_API gr_pwr_squelch_cc_sptr gr_make_pwr_squelch_cc(double db, double alpha, int ramp, bool gate);
49  gr_pwr_squelch_cc(double db, double alpha, int ramp, bool gate);
50 
51 protected:
52  virtual void update_state(const gr_complex &in);
53  virtual bool mute() const { return d_pwr < d_threshold; }
54 
55 public:
56  std::vector<float> squelch_range() const;
57 
58  double threshold() const { return 10*log10(d_threshold); }
59  void set_threshold(double db) { d_threshold = std::pow(10.0, db/10); }
60  void set_alpha(double alpha) { d_iir.set_taps(alpha); }
61 };
62 
63 #endif /* INCLUDED_GR_PWR_SQUELCH_CC_H */