GNU Radio 3.6.2 C++ API
digital_clock_recovery_mm_ff.h
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1 /* -*- c++ -*- */
2 /*
3  * Copyright 2004,2011 Free Software Foundation, Inc.
4  *
5  * This file is part of GNU Radio
6  *
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)
10  * any later version.
11  *
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.
16  *
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.
21  */
22 
23 #ifndef INCLUDED_DIGITAL_CLOCK_RECOVERY_MM_FF_H
24 #define INCLUDED_DIGITAL_CLOCK_RECOVERY_MM_FF_H
25 
26 #include <digital_api.h>
27 #include <gr_block.h>
28 #include <gr_math.h>
29 #include <stdio.h>
30 
32 
35 
36 // public constructor
39  float mu, float gain_mu,
40  float omega_relative_limit=0.001);
41 
42 /*!
43  * \brief Mueller and Müller (M&M) based clock recovery block with float input, float output.
44  * \ingroup sync_blk
45  * \ingroup digital
46  *
47  * This implements the Mueller and Müller (M&M) discrete-time error-tracking synchronizer.
48  *
49  * See "Digital Communication Receivers: Synchronization, Channel
50  * Estimation and Signal Processing" by Heinrich Meyr, Marc Moeneclaey, & Stefan Fechtel.
51  * ISBN 0-471-50275-8.
52  */
54 {
55  public:
57  void forecast(int noutput_items, gr_vector_int &ninput_items_required);
58  int general_work (int noutput_items,
59  gr_vector_int &ninput_items,
60  gr_vector_const_void_star &input_items,
61  gr_vector_void_star &output_items);
62  float mu() const { return d_mu;}
63  float omega() const { return d_omega;}
64  float gain_mu() const { return d_gain_mu;}
65  float gain_omega() const { return d_gain_omega;}
66 
67  void set_gain_mu (float gain_mu) { d_gain_mu = gain_mu; }
68  void set_gain_omega (float gain_omega) { d_gain_omega = gain_omega; }
69  void set_mu (float mu) { d_mu = mu; }
70  void set_omega (float omega){
71  d_omega = omega;
72  d_min_omega = omega*(1.0 - d_omega_relative_limit);
73  d_max_omega = omega*(1.0 + d_omega_relative_limit);
74  d_omega_mid = 0.5*(d_min_omega+d_max_omega);
75  }
76 
77 protected:
78  digital_clock_recovery_mm_ff (float omega, float gain_omega, float mu, float gain_mu,
79  float omega_relative_limit);
80 
81  private:
82  float d_mu; // fractional sample position [0.0, 1.0]
83  float d_omega; // nominal frequency
84  float d_min_omega; // minimum allowed omega
85  float d_omega_mid; // average omega
86  float d_max_omega; // maximum allowed omega
87  float d_gain_omega; // gain for adjusting omega
88  float d_gain_mu; // gain for adjusting mu
89  float d_last_sample;
90  gri_mmse_fir_interpolator *d_interp;
91  FILE *d_logfile;
92  float d_omega_relative_limit; // used to compute min and max omega
93 
95  digital_make_clock_recovery_mm_ff (float omega, float gain_omega,
96  float mu, float gain_mu,
97  float omega_relative_limit);
98 };
99 
100 #endif