<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> <title>GNU Radio 3.2.2 C++ API: gr_costas_loop_cc.h Source File</title> <link href="tabs.css" rel="stylesheet" type="text/css"/> <link href="navtree.css" rel="stylesheet" type="text/css"/> <script type="text/javascript" src="jquery.js"></script> <script type="text/javascript" src="navtree.js"></script> <script type="text/javascript" src="resize.js"></script> <script type="text/javascript"> $(document).ready(initResizable); </script> <link href="doxygen.css" rel="stylesheet" type="text/css"/> </head> <body> <!-- Generated by Doxygen 1.7.3 --> <div id="top"> <div id="titlearea"> <table cellspacing="0" cellpadding="0"> <tbody> <tr style="height: 56px;"> <td style="padding-left: 0.5em;"> <div id="projectname">GNU Radio 3.2.2 C++ API</div> </td> </tr> </tbody> </table> </div> </div> <div id="side-nav" class="ui-resizable side-nav-resizable"> <div id="nav-tree"> <div id="nav-tree-contents"> </div> </div> <div id="splitbar" style="-moz-user-select:none;" class="ui-resizable-handle"> </div> </div> <script type="text/javascript"> initNavTree('gr__costas__loop__cc_8h.html',''); </script> <div id="doc-content"> <div class="header"> <div class="headertitle"> <h1>gr_costas_loop_cc.h</h1> </div> </div> <div class="contents"> <a href="gr__costas__loop__cc_8h.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/* -*- c++ -*- */</span> <a name="l00002"></a>00002 <span class="comment">/*</span> <a name="l00003"></a>00003 <span class="comment"> * Copyright 2006 Free Software Foundation, Inc.</span> <a name="l00004"></a>00004 <span class="comment"> * </span> <a name="l00005"></a>00005 <span class="comment"> * This file is part of GNU Radio</span> <a name="l00006"></a>00006 <span class="comment"> * </span> <a name="l00007"></a>00007 <span class="comment"> * GNU Radio is free software; you can redistribute it and/or modify</span> <a name="l00008"></a>00008 <span class="comment"> * it under the terms of the GNU General Public License as published by</span> <a name="l00009"></a>00009 <span class="comment"> * the Free Software Foundation; either version 3, or (at your option)</span> <a name="l00010"></a>00010 <span class="comment"> * any later version.</span> <a name="l00011"></a>00011 <span class="comment"> * </span> <a name="l00012"></a>00012 <span class="comment"> * GNU Radio is distributed in the hope that it will be useful,</span> <a name="l00013"></a>00013 <span class="comment"> * but WITHOUT ANY WARRANTY; without even the implied warranty of</span> <a name="l00014"></a>00014 <span class="comment"> * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the</span> <a name="l00015"></a>00015 <span class="comment"> * GNU General Public License for more details.</span> <a name="l00016"></a>00016 <span class="comment"> * </span> <a name="l00017"></a>00017 <span class="comment"> * You should have received a copy of the GNU General Public License</span> <a name="l00018"></a>00018 <span class="comment"> * along with GNU Radio; see the file COPYING. If not, write to</span> <a name="l00019"></a>00019 <span class="comment"> * the Free Software Foundation, Inc., 51 Franklin Street,</span> <a name="l00020"></a>00020 <span class="comment"> * Boston, MA 02110-1301, USA.</span> <a name="l00021"></a>00021 <span class="comment"> */</span> <a name="l00022"></a>00022 <a name="l00023"></a>00023 <a name="l00024"></a>00024 <span class="preprocessor">#ifndef INCLUDED_GR_COSTAS_LOOP_CC_H</span> <a name="l00025"></a>00025 <span class="preprocessor"></span><span class="preprocessor">#define INCLUDED_GR_COSTAS_LOOP_CC_H</span> <a name="l00026"></a>00026 <span class="preprocessor"></span> <a name="l00027"></a>00027 <span class="preprocessor">#include <gr_sync_block.h></span> <a name="l00028"></a>00028 <span class="preprocessor">#include <stdexcept></span> <a name="l00029"></a>00029 <span class="preprocessor">#include <fstream></span> <a name="l00030"></a>00030 <a name="l00031"></a>00031 <span class="comment"></span> <a name="l00032"></a>00032 <span class="comment">/*! \brief A Costas loop carrier recovery module.</span> <a name="l00033"></a>00033 <span class="comment"> * \ingroup sync_blk</span> <a name="l00034"></a>00034 <span class="comment"> * </span> <a name="l00035"></a>00035 <span class="comment"> * The Costas loop locks to the center frequency of a signal and</span> <a name="l00036"></a>00036 <span class="comment"> * downconverts it to baseband. The second (order=2) order loop is</span> <a name="l00037"></a>00037 <span class="comment"> * used for BPSK where the real part of the output signal is the</span> <a name="l00038"></a>00038 <span class="comment"> * baseband BPSK signal and the imaginary part is the error</span> <a name="l00039"></a>00039 <span class="comment"> * signal. When order=4, it can be used for quadrature modulations</span> <a name="l00040"></a>00040 <span class="comment"> * where both I and Q (real and imaginary) are outputted.</span> <a name="l00041"></a>00041 <span class="comment"> *</span> <a name="l00042"></a>00042 <span class="comment"> * More details can be found online:</span> <a name="l00043"></a>00043 <span class="comment"> *</span> <a name="l00044"></a>00044 <span class="comment"> * J. Feigin, "Practical Costas loop design: Designing a simple and inexpensive</span> <a name="l00045"></a>00045 <span class="comment"> * BPSK Costas loop carrier recovery circuit," RF signal processing, pp. 20-36,</span> <a name="l00046"></a>00046 <span class="comment"> * 2002.</span> <a name="l00047"></a>00047 <span class="comment"> *</span> <a name="l00048"></a>00048 <span class="comment"> * http://rfdesign.com/images/archive/0102Feigin20.pdf</span> <a name="l00049"></a>00049 <span class="comment"> * </span> <a name="l00050"></a>00050 <span class="comment"> * \param alpha the loop gain used for phase adjustment</span> <a name="l00051"></a>00051 <span class="comment"> * \param beta the loop gain for frequency adjustments</span> <a name="l00052"></a>00052 <span class="comment"> * \param max_freq the maximum frequency deviation (radians/sample) the loop can handle</span> <a name="l00053"></a>00053 <span class="comment"> * \param min_freq the minimum frequency deviation (radians/sample) the loop can handle</span> <a name="l00054"></a>00054 <span class="comment"> * \param order the loop order, either 2 or 4</span> <a name="l00055"></a>00055 <span class="comment"> */</span> <a name="l00056"></a>00056 <span class="keyword">class </span><a class="code" href="classgr__costas__loop__cc.html" title="Carrier tracking PLL for QPSKinput: complex; output: complex The Costas loop can have two output str...">gr_costas_loop_cc</a>; <a name="l00057"></a>00057 <span class="keyword">typedef</span> <a class="code" href="classboost_1_1shared__ptr.html" title="shared_ptr documentation stub">boost::shared_ptr<gr_costas_loop_cc></a> <a class="code" href="classboost_1_1shared__ptr.html" title="shared_ptr documentation stub">gr_costas_loop_cc_sptr</a>; <a name="l00058"></a>00058 <a name="l00059"></a>00059 <a name="l00060"></a>00060 <a class="code" href="classboost_1_1shared__ptr.html" title="shared_ptr documentation stub">gr_costas_loop_cc_sptr</a> <a name="l00061"></a>00061 <a class="code" href="gr__costas__loop__cc_8h.html#a576068d8fc6fe98befe664d7dd4757c5">gr_make_costas_loop_cc</a> (<span class="keywordtype">float</span> <a class="code" href="classgr__costas__loop__cc.html#a14ba6242e070c7248b13dfd2a79baf3c" title="get the first order gain">alpha</a>, <span class="keywordtype">float</span> <a class="code" href="classgr__costas__loop__cc.html#a722713354285a81be2bd8b8216eacc5e" title="get the second order gain">beta</a>, <a name="l00062"></a>00062 <span class="keywordtype">float</span> max_freq, <span class="keywordtype">float</span> min_freq, <a name="l00063"></a>00063 <span class="keywordtype">int</span> order <a name="l00064"></a>00064 ) <span class="keywordflow">throw</span> (std::invalid_argument); <a name="l00065"></a>00065 <a name="l00066"></a>00066 <span class="comment"></span> <a name="l00067"></a>00067 <span class="comment">/*!</span> <a name="l00068"></a>00068 <span class="comment"> * \brief Carrier tracking PLL for QPSK</span> <a name="l00069"></a>00069 <span class="comment"> * \ingroup sync_blk</span> <a name="l00070"></a>00070 <span class="comment"> * input: complex; output: complex</span> <a name="l00071"></a>00071 <span class="comment"> * <br>The Costas loop can have two output streams:</span> <a name="l00072"></a>00072 <span class="comment"> * stream 1 is the baseband I and Q;</span> <a name="l00073"></a>00073 <span class="comment"> * stream 2 is the normalized frequency of the loop</span> <a name="l00074"></a>00074 <span class="comment"> *</span> <a name="l00075"></a>00075 <span class="comment"> * \p order must be 2 or 4.</span> <a name="l00076"></a>00076 <span class="comment"> */</span> <a name="l00077"></a><a class="code" href="classgr__costas__loop__cc.html">00077</a> <span class="keyword">class </span><a class="code" href="classgr__costas__loop__cc.html" title="Carrier tracking PLL for QPSKinput: complex; output: complex The Costas loop can have two output str...">gr_costas_loop_cc</a> : <span class="keyword">public</span> <a class="code" href="classgr__sync__block.html" title="synchronous 1:1 input to output with historyOverride work to provide the signal processing implementa...">gr_sync_block</a> <a name="l00078"></a>00078 { <a name="l00079"></a>00079 <span class="keyword">friend</span> <a class="code" href="classboost_1_1shared__ptr.html" title="shared_ptr documentation stub">gr_costas_loop_cc_sptr</a> <a class="code" href="classgr__costas__loop__cc.html#a576068d8fc6fe98befe664d7dd4757c5">gr_make_costas_loop_cc</a> (<span class="keywordtype">float</span> <a class="code" href="classgr__costas__loop__cc.html#a14ba6242e070c7248b13dfd2a79baf3c" title="get the first order gain">alpha</a>, <span class="keywordtype">float</span> <a class="code" href="classgr__costas__loop__cc.html#a722713354285a81be2bd8b8216eacc5e" title="get the second order gain">beta</a>, <a name="l00080"></a>00080 <span class="keywordtype">float</span> max_freq, <span class="keywordtype">float</span> min_freq, <a name="l00081"></a>00081 <span class="keywordtype">int</span> order <a name="l00082"></a>00082 ) <span class="keywordflow">throw</span> (std::invalid_argument); <a name="l00083"></a>00083 <a name="l00084"></a>00084 <span class="keywordtype">float</span> d_alpha, d_beta, d_max_freq, d_min_freq, d_phase, d_freq; <a name="l00085"></a>00085 <span class="keywordtype">int</span> d_order; <a name="l00086"></a>00086 <a name="l00087"></a>00087 <a class="code" href="classgr__costas__loop__cc.html" title="Carrier tracking PLL for QPSKinput: complex; output: complex The Costas loop can have two output str...">gr_costas_loop_cc</a> (<span class="keywordtype">float</span> alpha, <span class="keywordtype">float</span> beta, <a name="l00088"></a>00088 <span class="keywordtype">float</span> max_freq, <span class="keywordtype">float</span> min_freq, <a name="l00089"></a>00089 <span class="keywordtype">int</span> order <a name="l00090"></a>00090 ) <span class="keywordflow">throw</span> (std::invalid_argument); <a name="l00091"></a>00091 <span class="comment"></span> <a name="l00092"></a>00092 <span class="comment"> /*! \brief the phase detector circuit for fourth-order loops</span> <a name="l00093"></a>00093 <span class="comment"> * \param sample complex sample</span> <a name="l00094"></a>00094 <span class="comment"> * \return the phase error</span> <a name="l00095"></a>00095 <span class="comment"> */</span> <a name="l00096"></a>00096 <span class="keywordtype">float</span> phase_detector_4(<a class="code" href="gr__complex_8h.html#aec4bfe41433369afae9327f1b0bc9109">gr_complex</a> sample) <span class="keyword">const</span>; <span class="comment">// for QPSK</span> <a name="l00097"></a>00097 <span class="comment"></span> <a name="l00098"></a>00098 <span class="comment"> /*! \brief the phase detector circuit for second-order loops</span> <a name="l00099"></a>00099 <span class="comment"> * \param sample a complex sample</span> <a name="l00100"></a>00100 <span class="comment"> * \return the phase error</span> <a name="l00101"></a>00101 <span class="comment"> */</span> <a name="l00102"></a>00102 <span class="keywordtype">float</span> phase_detector_2(<a class="code" href="gr__complex_8h.html#aec4bfe41433369afae9327f1b0bc9109">gr_complex</a> sample) <span class="keyword">const</span>; <span class="comment">// for BPSK</span> <a name="l00103"></a>00103 <a name="l00104"></a>00104 <a name="l00105"></a>00105 float (<a class="code" href="classgr__costas__loop__cc.html" title="Carrier tracking PLL for QPSKinput: complex; output: complex The Costas loop can have two output str...">gr_costas_loop_cc</a>::*d_phase_detector)(<a class="code" href="gr__complex_8h.html#aec4bfe41433369afae9327f1b0bc9109">gr_complex</a> sample) <span class="keyword">const</span>; <a name="l00106"></a>00106 <a name="l00107"></a>00107 <span class="keyword">public</span>: <a name="l00108"></a>00108 <span class="comment"></span> <a name="l00109"></a>00109 <span class="comment"> /*! \brief set the first order gain</span> <a name="l00110"></a>00110 <span class="comment"> * \param alpha</span> <a name="l00111"></a>00111 <span class="comment"> */</span> <a name="l00112"></a>00112 <span class="keywordtype">void</span> <a class="code" href="classgr__costas__loop__cc.html#a724f57415af5103e02829b2b3a42a5b8" title="set the first order gain">set_alpha</a>(<span class="keywordtype">float</span> alpha); <a name="l00113"></a>00113 <span class="comment"></span> <a name="l00114"></a>00114 <span class="comment"> /*! \brief get the first order gain</span> <a name="l00115"></a>00115 <span class="comment"> * </span> <a name="l00116"></a>00116 <span class="comment"> */</span> <a name="l00117"></a><a class="code" href="classgr__costas__loop__cc.html#a14ba6242e070c7248b13dfd2a79baf3c">00117</a> <span class="keywordtype">float</span> <a class="code" href="classgr__costas__loop__cc.html#a14ba6242e070c7248b13dfd2a79baf3c" title="get the first order gain">alpha</a>()<span class="keyword"> const </span>{ <span class="keywordflow">return</span> d_alpha; } <a name="l00118"></a>00118 <span class="comment"></span> <a name="l00119"></a>00119 <span class="comment"> /*! \brief set the second order gain</span> <a name="l00120"></a>00120 <span class="comment"> * \param beta</span> <a name="l00121"></a>00121 <span class="comment"> */</span> <a name="l00122"></a>00122 <span class="keywordtype">void</span> <a class="code" href="classgr__costas__loop__cc.html#ad9eff0e7c944abc56298a0bf620c7e7b" title="set the second order gain">set_beta</a>(<span class="keywordtype">float</span> beta); <a name="l00123"></a>00123 <span class="comment"></span> <a name="l00124"></a>00124 <span class="comment"> /*! \brief get the second order gain</span> <a name="l00125"></a>00125 <span class="comment"> * </span> <a name="l00126"></a>00126 <span class="comment"> */</span> <a name="l00127"></a><a class="code" href="classgr__costas__loop__cc.html#a722713354285a81be2bd8b8216eacc5e">00127</a> <span class="keywordtype">float</span> <a class="code" href="classgr__costas__loop__cc.html#a722713354285a81be2bd8b8216eacc5e" title="get the second order gain">beta</a>()<span class="keyword"> const </span>{ <span class="keywordflow">return</span> d_beta; } <a name="l00128"></a>00128 <a name="l00129"></a>00129 <span class="keywordtype">int</span> <a class="code" href="classgr__costas__loop__cc.html#a14be21ec2c277635fee7bb6178e7eb84" title="just like gr_block::general_work, only this arranges to call consume_each for you">work</a> (<span class="keywordtype">int</span> noutput_items, <a name="l00130"></a>00130 <a class="code" href="classstd_1_1vector.html">gr_vector_const_void_star</a> &input_items, <a name="l00131"></a>00131 <a class="code" href="classstd_1_1vector.html">gr_vector_void_star</a> &output_items); <a name="l00132"></a>00132 <span class="comment"></span> <a name="l00133"></a>00133 <span class="comment"> /*! \brief returns the current NCO frequency in radians/sample</span> <a name="l00134"></a>00134 <span class="comment"> *</span> <a name="l00135"></a>00135 <span class="comment"> */</span> <a name="l00136"></a><a class="code" href="classgr__costas__loop__cc.html#a860d750da80d9cf1589750551632194a">00136</a> <span class="keywordtype">float</span> <a class="code" href="classgr__costas__loop__cc.html#a860d750da80d9cf1589750551632194a" title="returns the current NCO frequency in radians/sample">freq</a>()<span class="keyword"> const </span>{ <span class="keywordflow">return</span> d_freq; } <a name="l00137"></a>00137 }; <a name="l00138"></a>00138 <a name="l00139"></a>00139 <span class="preprocessor">#endif</span> </pre></div></div> </div> <div id="nav-path" class="navpath"> <ul> <li class="navelem"><a class="el" href="gr__costas__loop__cc_8h.html">gr_costas_loop_cc.h</a> </li> <li class="footer">Generated on Thu Feb 17 2011 for GNU Radio 3.2.2 C++ API by  <a href="http://www.doxygen.org/index.html"> <img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.7.3 </li> </ul> </div> </body> </html>