GNU Radio 3.6.5 C++ API

gr_peak_detector2_fb.h

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00001 /* -*- c++ -*- */
00002 /*
00003  * Copyright 2007 Free Software Foundation, Inc.
00004  *
00005  * This file is part of GNU Radio
00006  *
00007  * GNU Radio is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 3, or (at your option)
00010  * any later version.
00011  *
00012  * GNU Radio is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU General Public License
00018  * along with GNU Radio; see the file COPYING.  If not, write to
00019  * the Free Software Foundation, Inc., 51 Franklin Street,
00020  * Boston, MA 02110-1301, USA.
00021  */
00022 
00023 #ifndef INCLUDED_gr_peak_detector2_FB_H
00024 #define INCLUDED_gr_peak_detector2_FB_H
00025 
00026 #include <gr_core_api.h>
00027 #include <gr_sync_block.h>
00028 
00029 class gr_peak_detector2_fb;
00030 typedef boost::shared_ptr<gr_peak_detector2_fb> gr_peak_detector2_fb_sptr;
00031 
00032 GR_CORE_API gr_peak_detector2_fb_sptr gr_make_peak_detector2_fb (float threshold_factor_rise = 7,
00033                                                      int look_ahead = 1000,
00034                                                      float alpha = 0.001);
00035 
00036 /*!
00037  * \brief Detect the peak of a signal
00038  *
00039  * If a peak is detected, this block outputs a 1,
00040  * or it outputs 0's.  A separate debug output may be connected, to
00041  * view the internal EWMA described below.
00042  *
00043  * \param threshold_factor_rise The threshold factor determins when a peak
00044  *        is present. An EWMA average of the signal is calculated and when the
00045  *        value of the signal goes over threshold_factor_rise*average, we
00046  *        call the peak.
00047  * \param look_ahead The look-ahead value is used when the threshold is
00048  *        found to locate the peak within this range.
00049  * \param alpha The gain value of a single-pole moving average filter
00050  */
00051 
00052 class GR_CORE_API gr_peak_detector2_fb : public gr_sync_block
00053 {
00054   friend GR_CORE_API gr_peak_detector2_fb_sptr
00055   gr_make_peak_detector2_fb (float threshold_factor_rise, int look_ahead, float alpha);
00056 
00057   gr_peak_detector2_fb (float threshold_factor_rise, int look_ahead, float alpha);
00058 
00059 private:
00060   float d_threshold_factor_rise;
00061   int d_look_ahead;
00062   int d_look_ahead_remaining;
00063   int d_peak_ind;
00064   float d_peak_val;
00065   float d_alpha;
00066   float d_avg;
00067   bool d_found;
00068 
00069 public:
00070 
00071   /*! \brief Set the threshold factor value for the rise time
00072    *  \param thr new threshold factor
00073    */
00074   void set_threshold_factor_rise(float thr) { d_threshold_factor_rise = thr; }
00075 
00076   /*! \brief Set the look-ahead factor
00077    *  \param look new look-ahead factor
00078    */
00079   void set_look_ahead(int look) { d_look_ahead = look; }
00080 
00081   /*! \brief Set the running average alpha
00082    *  \param alpha new alpha for running average
00083    */
00084   void set_alpha(int alpha) { d_alpha = alpha; }
00085 
00086   /*! \brief Get the threshold factor value for the rise time
00087    *  \return threshold factor
00088    */
00089   float threshold_factor_rise() { return d_threshold_factor_rise; }
00090 
00091   /*! \brief Get the look-ahead factor value
00092    *  \return look-ahead factor
00093    */
00094   int look_ahead() { return d_look_ahead; }
00095 
00096   /*! \brief Get the alpha value of the running average
00097    *  \return alpha
00098    */
00099   float alpha() { return d_alpha; }
00100 
00101   int work (int noutput_items,
00102             gr_vector_const_void_star &input_items,
00103             gr_vector_void_star &output_items);
00104 };
00105 
00106 #endif
00107 
00108