gr_rms_ff.cc

gnuradio软件无线电源程序.现在的手机多基于软件无线电

/* -*- c++ -*- */
/*
 * Copyright 2005 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 2, 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., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gr_rms_ff.h>
#include <gr_io_signature.h>
#include <cmath>

gr_rms_ff_sptr
gr_make_rms_ff(double alpha)
{
  return gr_rms_ff_sptr(new gr_rms_ff(alpha));
}

gr_rms_ff::gr_rms_ff (double alpha)
  : gr_sync_block ("rms_ff",
		   gr_make_io_signature(1, 1, sizeof(float)),
		   gr_make_io_signature(1, 1, sizeof(float))),
    d_iir(alpha)
{

}

gr_rms_ff::~gr_rms_ff()
{
}


int
gr_rms_ff::work(int noutput_items,
			   gr_vector_const_void_star &input_items,
			   gr_vector_void_star &output_items)
{
  const float *in = (const float *) input_items[0];
  float *out = (float *) output_items[0];

  for (int i = 0; i < noutput_items; i++){
    double mag_sqrd = in[i]*in[i];
    double f = d_iir.filter(mag_sqrd);
    out[i] = sqrt(f);
  }

  return noutput_items;
}

void
gr_rms_ff::set_alpha(double alpha)
{
  d_iir.set_taps(alpha);
}