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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_MPSK_SNR_EST_CC_H
#define INCLUDED_DIGITAL_MPSK_SNR_EST_CC_H
#include <digital_api.h>
#include <gr_sync_block.h>
#include <digital_impl_mpsk_snr_est.h>
class digital_mpsk_snr_est_cc;
typedef boost::shared_ptr<digital_mpsk_snr_est_cc> digital_mpsk_snr_est_cc_sptr;
DIGITAL_API digital_mpsk_snr_est_cc_sptr
digital_make_mpsk_snr_est_cc(snr_est_type_t type,
int tag_nsamples=10000,
double alpha=0.001);
//! \brief A block for computing SNR of a signal.
/*! \ingroup snr_blk
*
* This block can be used to monitor and retrieve estimations of the
* signal SNR. It is designed to work in a flowgraph and passes all
* incoming data along to its output.
*
* The block 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_mpsk_snr_est_cc : 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 tag name, 'snr', d_me is the block name + unique ID
pmt::pmt_t d_key, d_me;
/*! 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 tag_nsamples: after this many samples, a tag containing
* the SNR (key='snr') will be sent
* \param alpha: the update rate of internal running average
* calculations.
*/
friend DIGITAL_API digital_mpsk_snr_est_cc_sptr
digital_make_mpsk_snr_est_cc(snr_est_type_t type,
int tag_nsamples,
double alpha);
// Private constructor
digital_mpsk_snr_est_cc(snr_est_type_t type,
int tag_nsamples,
double alpha);
public:
~digital_mpsk_snr_est_cc();
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 tags
int tag_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 tags
void set_tag_nsample(int n);
//! Set the running-average coefficient
void set_alpha(double alpha);
};
#endif /* INCLUDED_DIGITAL_MPSK_SNR_EST_CC_H */
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