GNU Radio Manual and C++ API Reference 3.7.14.0
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probe_mpsk_snr_est_c.h
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1/* -*- c++ -*- */
2/*
3 * Copyright 2011,2012 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
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10 * any later version.
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14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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21 */
22
23#ifndef INCLUDED_DIGITAL_PROBE_MPSK_SNR_EST_C_H
24#define INCLUDED_DIGITAL_PROBE_MPSK_SNR_EST_C_H
25
28#include <gnuradio/sync_block.h>
29
30namespace gr {
31namespace digital {
32
33/*!
34 * \brief A probe for computing SNR of a PSK signal.
35 * \ingroup measurement_tools_blk
36 *
37 * \details
38 * This is a probe block (a sink) that can be used to monitor and
39 * retrieve estimations of the signal SNR. This probe is designed
40 * for use with M-PSK signals especially. The type of estimator is
41 * specified as the \p type parameter in the constructor. The
42 * estimators tend to trade off performance for accuracy, although
43 * experimentation should be done to figure out the right approach
44 * for a given implementation. Further, the current set of
45 * estimators are designed and proven theoretically under AWGN
46 * conditions; some amount of error should be assumed and/or
47 * estimated for real channel conditions.
48 *
49 * The block has three output message ports that will emit a
50 * message every msg_samples number of samples. These message
51 * ports are:
52 * \li snr: the current SNR estimate (in dB)
53 * \li signal: the current signal power estimate (in dBx)
54 * \li noise: the current noise power estimate (in dBx)
55 *
56 * Some calibration is required to convert dBx of the signal and
57 * noise power estimates to real measurements, such as dBm.
58 */
60{
61public:
62 // gr::digital::probe_mpsk_snr_est_c::sptr
63 typedef boost::shared_ptr<probe_mpsk_snr_est_c> sptr;
64
65 /*! Make an MPSK SNR probe.
66 *
67 * Parameters:
68 *
69 * \param type: the type of estimator to use see
70 * gr::digital::snr_est_type_t for details about the types.
71 * \param msg_nsamples: [not implemented yet] after this many
72 * samples, a message containing the SNR (key='snr') will be sent
73 * \param alpha: the update rate of internal running average
74 * calculations.
75 */
76 static sptr make(snr_est_type_t type, int msg_nsamples = 10000, double alpha = 0.001);
77
78 //! Return the estimated signal-to-noise ratio in decibels
79 virtual double snr() = 0;
80
81 //! Return the estimated signal power in decibels
82 virtual double signal() = 0;
83
84 //! Return the estimated noise power in decibels
85 virtual double noise() = 0;
86
87 //! Return the type of estimator in use
88 virtual snr_est_type_t type() const = 0;
89
90 //! Return how many samples between SNR messages
91 virtual int msg_nsample() const = 0;
92
93 //! Get the running-average coefficient
94 virtual double alpha() const = 0;
95
96 //! Set type of estimator to use
97 virtual void set_type(snr_est_type_t t) = 0;
98
99 //! Set the number of samples between SNR messages
100 virtual void set_msg_nsample(int n) = 0;
101
102 //! Set the running-average coefficient
103 virtual void set_alpha(double alpha) = 0;
104};
105
106} /* namespace digital */
107} /* namespace gr */
108
109#endif /* INCLUDED_DIGITAL_PROBE_MPSK_SNR_EST_C_H */
A probe for computing SNR of a PSK signal.
Definition: probe_mpsk_snr_est_c.h:60
virtual snr_est_type_t type() const =0
Return the type of estimator in use.
virtual void set_msg_nsample(int n)=0
Set the number of samples between SNR messages.
virtual double signal()=0
Return the estimated signal power in decibels.
static sptr make(snr_est_type_t type, int msg_nsamples=10000, double alpha=0.001)
boost::shared_ptr< probe_mpsk_snr_est_c > sptr
Definition: probe_mpsk_snr_est_c.h:63
virtual double noise()=0
Return the estimated noise power in decibels.
virtual double alpha() const =0
Get the running-average coefficient.
virtual int msg_nsample() const =0
Return how many samples between SNR messages.
virtual double snr()=0
Return the estimated signal-to-noise ratio in decibels.
virtual void set_alpha(double alpha)=0
Set the running-average coefficient.
virtual void set_type(snr_est_type_t t)=0
Set type of estimator to use.
synchronous 1:1 input to output with history
Definition: sync_block.h:38
#define DIGITAL_API
Definition: gr-digital/include/gnuradio/digital/api.h:30
snr_est_type_t
A block for computing SNR of a signal.
Definition: mpsk_snr_est.h:46
Include this header to use the message passing features.
Definition: basic_block.h:45