<!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_probe_mpsk_snr_c Class Reference</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('classgr__probe__mpsk__snr__c.html',''); </script> <div id="doc-content"> <div class="header"> <div class="summary"> <a href="#pub-methods">Public Member Functions</a> | <a href="#friends">Friends</a> </div> <div class="headertitle"> <h1>gr_probe_mpsk_snr_c Class Reference<div class="ingroups"><a class="el" href="group__sink__blk.html">Signal Sinks</a></div></h1> </div> </div> <div class="contents"> <!-- doxytag: class="gr_probe_mpsk_snr_c" --><!-- doxytag: inherits="gr_sync_block" --> <p><code>#include <<a class="el" href="gr__probe__mpsk__snr__c_8h_source.html">gr_probe_mpsk_snr_c.h</a>></code></p> <div class="dynheader"> Inheritance diagram for gr_probe_mpsk_snr_c:</div> <div class="dyncontent"> <div class="center"><img src="classgr__probe__mpsk__snr__c__inherit__graph.png" border="0" usemap="#gr__probe__mpsk__snr__c_inherit__map" alt="Inheritance graph"/></div> <map name="gr__probe__mpsk__snr__c_inherit__map" id="gr__probe__mpsk__snr__c_inherit__map"> <area shape="rect" id="node2" href="classgr__sync__block.html" title="synchronous 1:1 input to output with historyOverride work to provide the signal processing implementa..." alt="" coords="27,160,133,189"/><area shape="rect" id="node4" href="classgr__block.html" title="The abstract base class for all 'terminal' processing blocks.A signal processing flow is cons..." alt="" coords="45,83,115,112"/><area shape="rect" id="node6" href="classgr__basic__block.html" title="The abstract base class for all signal processing blocks.Basic blocks are the bare abstraction of an ..." alt="" coords="25,5,135,35"/></map> <center><span class="legend">[<a target="top" href="graph_legend.html">legend</a>]</span></center></div> <p><a href="classgr__probe__mpsk__snr__c-members.html">List of all members.</a></p> <table class="memberdecls"> <tr><td colspan="2"><h2><a name="pub-methods"></a> Public Member Functions</h2></td></tr> <tr><td class="memItemLeft" align="right" valign="top"> </td><td class="memItemRight" valign="bottom"><a class="el" href="classgr__probe__mpsk__snr__c.html#a257b81c1f5661c4a2e3db77e881363b7">~gr_probe_mpsk_snr_c</a> ()</td></tr> <tr><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="classgr__probe__mpsk__snr__c.html#a932b6d17f06f2e51bb24ef8d11d96094">work</a> (int noutput_items, <a class="el" href="classstd_1_1vector.html">gr_vector_const_void_star</a> &input_items, <a class="el" href="classstd_1_1vector.html">gr_vector_void_star</a> &output_items)</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">just like <a class="el" href="classgr__block.html#a137b93d87dc83bbdb6369d33f4ea8197" title="compute output items from input items">gr_block::general_work</a>, only this arranges to call consume_each for you <a href="#a932b6d17f06f2e51bb24ef8d11d96094"></a><br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top">double </td><td class="memItemRight" valign="bottom"><a class="el" href="classgr__probe__mpsk__snr__c.html#ad1a5fdb5387eb6d27871d141ee72a73a">signal_mean</a> () const </td></tr> <tr><td class="memItemLeft" align="right" valign="top">double </td><td class="memItemRight" valign="bottom"><a class="el" href="classgr__probe__mpsk__snr__c.html#a8e6aa81e04d98ca22a0d6b0aedba89c4">noise_variance</a> () const </td></tr> <tr><td class="memItemLeft" align="right" valign="top">double </td><td class="memItemRight" valign="bottom"><a class="el" href="classgr__probe__mpsk__snr__c.html#a44a7b257bdb5b255e566a9d7173032ab">snr</a> () const </td></tr> <tr><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="classgr__probe__mpsk__snr__c.html#a1d1a50fbbf5190c46b9c9d8cdd826fb2">set_alpha</a> (double alpha)</td></tr> <tr><td colspan="2"><h2><a name="friends"></a> Friends</h2></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="el" href="classboost_1_1shared__ptr.html">gr_probe_mpsk_snr_c_sptr</a> </td><td class="memItemRight" valign="bottom"><a class="el" href="classgr__probe__mpsk__snr__c.html#a86c0b05292da46db0b40e4218d034d26">gr_make_probe_mpsk_snr_c</a> (double alpha)</td></tr> </table> <hr/><a name="_details"></a><h2>Detailed Description</h2> <div class="textblock"><p>Compute the estimate SNR of an MPSK signal using the Squared Signal to Noise Variance (SNV) technique.</p> <p>This technique assumes an AWGN channel.</p> <dl><dt><b>Parameters:</b></dt><dd> <table class="params"> <tr><td class="paramname">alpha</td><td>Mean and variance smoothing filter constant</td></tr> </table> </dd> </dl> <p>Compute the running average of the signal mean and noise variance. The estimated signal mean, noise variance, and SNR are available via accessors.</p> <p>This SNR estimator is inaccurate below about 7dB SNR. </p> </div><hr/><h2>Constructor & Destructor Documentation</h2> <a class="anchor" id="a257b81c1f5661c4a2e3db77e881363b7"></a><!-- doxytag: member="gr_probe_mpsk_snr_c::~gr_probe_mpsk_snr_c" ref="a257b81c1f5661c4a2e3db77e881363b7" args="()" --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">gr_probe_mpsk_snr_c::~gr_probe_mpsk_snr_c </td> <td>(</td> <td class="paramname"></td><td>)</td> <td></td> </tr> </table> </div> <div class="memdoc"> </div> </div> <hr/><h2>Member Function Documentation</h2> <a class="anchor" id="a8e6aa81e04d98ca22a0d6b0aedba89c4"></a><!-- doxytag: member="gr_probe_mpsk_snr_c::noise_variance" ref="a8e6aa81e04d98ca22a0d6b0aedba89c4" args="() const " --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">double gr_probe_mpsk_snr_c::noise_variance </td> <td>(</td> <td class="paramname"></td><td>)</td> <td> const<code> [inline]</code></td> </tr> </table> </div> <div class="memdoc"> </div> </div> <a class="anchor" id="a1d1a50fbbf5190c46b9c9d8cdd826fb2"></a><!-- doxytag: member="gr_probe_mpsk_snr_c::set_alpha" ref="a1d1a50fbbf5190c46b9c9d8cdd826fb2" args="(double alpha)" --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">void gr_probe_mpsk_snr_c::set_alpha </td> <td>(</td> <td class="paramtype">double </td> <td class="paramname"><em>alpha</em></td><td>)</td> <td></td> </tr> </table> </div> <div class="memdoc"> </div> </div> <a class="anchor" id="ad1a5fdb5387eb6d27871d141ee72a73a"></a><!-- doxytag: member="gr_probe_mpsk_snr_c::signal_mean" ref="ad1a5fdb5387eb6d27871d141ee72a73a" args="() const " --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">double gr_probe_mpsk_snr_c::signal_mean </td> <td>(</td> <td class="paramname"></td><td>)</td> <td> const<code> [inline]</code></td> </tr> </table> </div> <div class="memdoc"> </div> </div> <a class="anchor" id="a44a7b257bdb5b255e566a9d7173032ab"></a><!-- doxytag: member="gr_probe_mpsk_snr_c::snr" ref="a44a7b257bdb5b255e566a9d7173032ab" args="() const " --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">double gr_probe_mpsk_snr_c::snr </td> <td>(</td> <td class="paramname"></td><td>)</td> <td> const</td> </tr> </table> </div> <div class="memdoc"> </div> </div> <a class="anchor" id="a932b6d17f06f2e51bb24ef8d11d96094"></a><!-- doxytag: member="gr_probe_mpsk_snr_c::work" ref="a932b6d17f06f2e51bb24ef8d11d96094" args="(int noutput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)" --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">int gr_probe_mpsk_snr_c::work </td> <td>(</td> <td class="paramtype">int </td> <td class="paramname"><em>noutput_items</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype"><a class="el" href="classstd_1_1vector.html">gr_vector_const_void_star</a> & </td> <td class="paramname"><em>input_items</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype"><a class="el" href="classstd_1_1vector.html">gr_vector_void_star</a> & </td> <td class="paramname"><em>output_items</em> </td> </tr> <tr> <td></td> <td>)</td> <td></td><td><code> [virtual]</code></td> </tr> </table> </div> <div class="memdoc"> <p>just like <a class="el" href="classgr__block.html#a137b93d87dc83bbdb6369d33f4ea8197" title="compute output items from input items">gr_block::general_work</a>, only this arranges to call consume_each for you </p> <p>The user must override work to define the signal processing code </p> <p>Implements <a class="el" href="classgr__sync__block.html#a0c523f4285a6eb690f677ee6295ab117">gr_sync_block</a>.</p> </div> </div> <hr/><h2>Friends And Related Function Documentation</h2> <a class="anchor" id="a86c0b05292da46db0b40e4218d034d26"></a><!-- doxytag: member="gr_probe_mpsk_snr_c::gr_make_probe_mpsk_snr_c" ref="a86c0b05292da46db0b40e4218d034d26" args="(double alpha)" --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname"><a class="el" href="classboost_1_1shared__ptr.html">gr_probe_mpsk_snr_c_sptr</a> gr_make_probe_mpsk_snr_c </td> <td>(</td> <td class="paramtype">double </td> <td class="paramname"><em>alpha</em></td><td>)</td> <td><code> [friend]</code></td> </tr> </table> </div> <div class="memdoc"> </div> </div> <hr/>The documentation for this class was generated from the following file:<ul> <li><a class="el" href="gr__probe__mpsk__snr__c_8h_source.html">gr_probe_mpsk_snr_c.h</a></li> </ul> </div> </div> <div id="nav-path" class="navpath"> <ul> <li class="navelem"><a class="el" href="classgr__probe__mpsk__snr__c.html">gr_probe_mpsk_snr_c</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>