/* -*- c++ -*- */

/*

 * Copyright 2006,2010,2011 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 3, 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., 51 Franklin Street,

 * Boston, MA 02110-1301, USA.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <gr_pll_carriertracking_cc.h>

#include <gr_io_signature.h>

#include <gr_sincos.h>

#include <math.h>

#include <gr_math.h>

#ifndef M_TWOPI

#define M_TWOPI (2.0f*M_PI)

#endif

gr_pll_carriertracking_cc_sptr

gr_make_pll_carriertracking_cc (float loop_bw, float max_freq, float min_freq)

{

  return gnuradio::get_initial_sptr(new gr_pll_carriertracking_cc (loop_bw, max_freq, min_freq));

}

gr_pll_carriertracking_cc::gr_pll_carriertracking_cc (float loop_bw,

                                                      float max_freq,

                                                      float min_freq)

  : gr_sync_block ("pll_carriertracking_cc",

                   gr_make_io_signature (1, 1, sizeof (gr_complex)),

                   gr_make_io_signature (1, 1, sizeof (gr_complex))),

    gri_control_loop(loop_bw, max_freq, min_freq),

    d_locksig(0), d_lock_threshold(0), d_squelch_enable(false)

{

}

float

gr_pll_carriertracking_cc::mod_2pi (float in)

{

  if(in>M_PI)

    return in-M_TWOPI;

  else if(in<-M_PI)

    return in+M_TWOPI;

  else

    return in;

}

float

gr_pll_carriertracking_cc::phase_detector(gr_complex sample,float ref_phase)

{

  float sample_phase;

  //  sample_phase = atan2(sample.imag(),sample.real());

  sample_phase = gr_fast_atan2f(sample.imag(),sample.real());

  return mod_2pi(sample_phase-ref_phase);

}

bool

gr_pll_carriertracking_cc::lock_detector(void)

{

    return (fabsf(d_locksig) > d_lock_threshold);

}

bool

gr_pll_carriertracking_cc::squelch_enable(bool set_squelch)

{

    return d_squelch_enable = set_squelch;

}

float

gr_pll_carriertracking_cc::set_lock_threshold(float threshold)

{

    return d_lock_threshold = threshold;

}

int

gr_pll_carriertracking_cc::work (int noutput_items,

                                 gr_vector_const_void_star &input_items,

                                 gr_vector_void_star &output_items)

{

  const gr_complex *iptr = (gr_complex *) input_items[0];

  gr_complex *optr = (gr_complex *) output_items[0];

  float error;

  float t_imag, t_real;

  for (int i = 0; i < noutput_items; i++){

    gr_sincosf(d_phase, &t_imag, &t_real);

    optr[i] = iptr[i] * gr_complex(t_real, -t_imag);

    error = phase_detector(iptr[i],d_phase);

    advance_loop(error);

    phase_wrap();

    frequency_limit();

    d_locksig = d_locksig * (1.0 - d_alpha) + \

      d_alpha*(iptr[i].real() * t_real + iptr[i].imag() * t_imag);

    if ((d_squelch_enable) && !lock_detector())

      optr[i] = 0;

  }

  return noutput_items;

}