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 2, 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_pll_carriertracking_cc.h>
28 #include <gr_io_signature.h>
29 #include <gr_sincos.h>
32 #define M_TWOPI (2*M_PI)
34 gr_pll_carriertracking_cc_sptr
35 gr_make_pll_carriertracking_cc (float alpha, float beta, float max_freq, float min_freq)
37 return gr_pll_carriertracking_cc_sptr (new gr_pll_carriertracking_cc (alpha, beta, max_freq, min_freq));
40 gr_pll_carriertracking_cc::gr_pll_carriertracking_cc (float alpha, float beta, float max_freq, float min_freq)
41 : gr_sync_block ("pll_carriertracking_cc",
42 gr_make_io_signature (1, 1, sizeof (gr_complex)),
43 gr_make_io_signature (1, 1, sizeof (gr_complex))),
44 d_alpha(alpha), d_beta(beta),
45 d_max_freq(max_freq), d_min_freq(min_freq),
46 d_phase(0), d_freq((max_freq+min_freq)/2),
47 d_locksig(0),d_lock_threshold(0),d_squelch_enable(false)
52 gr_pll_carriertracking_cc::mod_2pi (float in)
63 gr_pll_carriertracking_cc::phase_detector(gr_complex sample,float ref_phase)
66 sample_phase = atan2(sample.imag(),sample.real());
67 return mod_2pi(sample_phase-ref_phase);
71 gr_pll_carriertracking_cc::lock_detector(void)
73 return (fabs(d_locksig) > d_lock_threshold);
77 gr_pll_carriertracking_cc::squelch_enable(bool set_squelch)
79 return d_squelch_enable = set_squelch;
83 gr_pll_carriertracking_cc::set_lock_threshold(float threshold)
85 return d_lock_threshold = threshold;
89 gr_pll_carriertracking_cc::work (int noutput_items,
90 gr_vector_const_void_star &input_items,
91 gr_vector_void_star &output_items)
93 const gr_complex *iptr = (gr_complex *) input_items[0];
94 gr_complex *optr = (gr_complex *) output_items[0];
99 for (int i = 0; i < noutput_items; i++){
100 error = phase_detector(iptr[i],d_phase);
102 d_freq = d_freq + d_beta * error;
103 d_phase = mod_2pi(d_phase + d_freq + d_alpha * error);
105 if (d_freq > d_max_freq)
107 else if (d_freq < d_min_freq)
109 gr_sincosf(d_phase,&t_imag,&t_real);
110 optr[i] = iptr[i] * gr_complex(t_real,-t_imag);
111 d_locksig = d_locksig * (1.0 - d_alpha) + d_alpha*(iptr[i].real() * t_real + iptr[i].imag() * t_imag);
113 if ((d_squelch_enable) && !lock_detector())
116 return noutput_items;