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/* -*- c++ -*- */
/*
* Copyright 2011 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
* GNU Radio is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef INCLUDED_DIGITAL_PROBE_MPSK_SNR_EST_C_H
#define INCLUDED_DIGITAL_PROBE_MPSK_SNR_EST_C_H
#include <digital_api.h>
#include <gr_sync_block.h>
#include <digital_impl_mpsk_snr_est.h>
class digital_probe_mpsk_snr_est_c;
typedef boost::shared_ptr<digital_probe_mpsk_snr_est_c> digital_probe_mpsk_snr_est_c_sptr;
DIGITAL_API digital_probe_mpsk_snr_est_c_sptr
digital_make_probe_mpsk_snr_est_c(snr_est_type_t type,
int msg_nsamples=10000,
double alpha=0.001);
//! \brief A probe for computing SNR of a signal.
/*! \ingroup snr_blk
*
* This is a probe block (a sink) that can be used to monitor and
* retrieve estimations of the signal SNR. This probe is designed for
* use with M-PSK signals especially. The type of estimator is
* specified as the \p type parameter in the constructor. The
* estimators tend to trade off performance for accuracy, although
* experimentation should be done to figure out the right approach
* for a given implementation. Further, the current set of estimators
* are designed and proven theoretically under AWGN conditions; some
* amount of error should be assumed and/or estimated for real
* channel conditions.
*/
class DIGITAL_API digital_probe_mpsk_snr_est_c : public gr_sync_block
{
private:
snr_est_type_t d_type;
int d_nsamples, d_count;
double d_alpha;
digital_impl_mpsk_snr_est *d_snr_est;
//d_key is the message name, 'snr'
pmt::pmt_t d_key;
/*! Factory function returning shared pointer of this class
*
* Parameters:
*
* \param type: the type of estimator to use \ref ref_snr_est_types
* "snr_est_type_t" for details about the available types.
* \param msg_nsamples: [not implemented yet] after this many
* samples, a message containing the SNR (key='snr') will be sent
* \param alpha: the update rate of internal running average
* calculations.
*/
friend DIGITAL_API digital_probe_mpsk_snr_est_c_sptr
digital_make_probe_mpsk_snr_est_c(snr_est_type_t type,
int msg_nsamples,
double alpha);
//! Private constructor
digital_probe_mpsk_snr_est_c(snr_est_type_t type,
int msg_nsamples,
double alpha);
public:
~digital_probe_mpsk_snr_est_c();
int work (int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items);
//! Return the estimated signal-to-noise ratio in decibels
double snr();
//! Return the type of estimator in use
snr_est_type_t type() const;
//! Return how many samples between SNR messages
int msg_nsample() const;
//! Get the running-average coefficient
double alpha() const;
//! Set type of estimator to use
void set_type(snr_est_type_t t);
//! Set the number of samples between SNR messages
void set_msg_nsample(int n);
//! Set the running-average coefficient
void set_alpha(double alpha);
};
#endif /* INCLUDED_DIGITAL_PROBE_MPSK_SNR_EST_C_H */
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