<!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 3.3.0 C++ API: gr_probe_mpsk_snr_c Class Reference</title> <link href="tabs.css" rel="stylesheet" type="text/css"/> <link href="doxygen.css" rel="stylesheet" type="text/css"/> </head> <body> <!-- Generated by Doxygen 1.6.3 --> <div class="contents"> <h1>gr_probe_mpsk_snr_c Class Reference<br/> <small> [<a class="el" href="group__sink__blk.html">Signal Sinks</a>]</small> </h1><!-- 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="dynsection"> <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..." alt="" coords="27,315,133,344"/><area shape="rect" id="node4" href="classgr__block.html" title="The abstract base class for all 'terminal' processing blocks.A signal processing..." alt="" coords="45,237,115,267"/><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..." alt="" coords="25,160,135,189"/><area shape="rect" id="node8" href="classgr__msg__accepter.html" title="Accepts messages and inserts them into a message queue, then notifies subclass gr_basic_block..." alt="" coords="19,83,141,112"/><area shape="rect" id="node10" href="classgruel_1_1msg__accepter.html" title="Virtual base class that accepts messages." alt="" coords="11,5,149,35"/></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 border="0" cellpadding="0" cellspacing="0"> <tr><td colspan="2"><h2>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>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> <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 border="0" cellspacing="2" cellpadding="0"> <tr><td valign="top"></td><td valign="top"><em>alpha</em> </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> <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><td> </td> </tr> <tr> <td></td> <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> <hr class="footer"/><address style="text-align: right;"><small>Generated on Wed Dec 29 19:52:53 2010 for GNU Radio 3.3.0 C++ API by <a href="http://www.doxygen.org/index.html"> <img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.6.3 </small></address> </body> </html>