3 * Copyright 2004,2005 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.
27 #include <gr_quadrature_demod_cf.h>
28 #include <gr_io_signature.h>
31 gr_quadrature_demod_cf::gr_quadrature_demod_cf (float gain)
32 : gr_sync_block ("quadrature_demod_cf",
33 gr_make_io_signature (1, 1, sizeof (gr_complex)),
34 gr_make_io_signature (1, 1, sizeof (float))),
37 set_history (2); // we need to look at the previous value
40 gr_quadrature_demod_cf_sptr
41 gr_make_quadrature_demod_cf (float gain)
43 return gr_quadrature_demod_cf_sptr (new gr_quadrature_demod_cf (gain));
47 gr_quadrature_demod_cf::work (int noutput_items,
48 gr_vector_const_void_star &input_items,
49 gr_vector_void_star &output_items)
51 gr_complex *in = (gr_complex *) input_items[0];
52 float *out = (float *) output_items[0];
53 in++; // ensure that in[-1] is valid
55 for (int i = 0; i < noutput_items; i++){
56 gr_complex product = in[i] * conj (in[i-1]);
57 // out[i] = d_gain * arg (product);
58 out[i] = d_gain * gr_fast_atan2f(imag(product), real(product));