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/* -*- c++ -*- */
/*
* Copyright 2011,2012 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.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "mpsk_snr_est_cc_impl.h"
#include <gnuradio/io_signature.h>
#include <cstdio>
namespace gr {
namespace digital {
mpsk_snr_est_cc::sptr
mpsk_snr_est_cc::make(snr_est_type_t type, int tag_nsamples, double alpha)
{
return gnuradio::get_initial_sptr(
new mpsk_snr_est_cc_impl(type, tag_nsamples, alpha));
}
mpsk_snr_est_cc_impl::mpsk_snr_est_cc_impl(snr_est_type_t type,
int tag_nsamples,
double alpha)
: sync_block("mpsk_snr_est_cc",
io_signature::make(1, 1, sizeof(gr_complex)),
io_signature::make(1, 1, sizeof(gr_complex)))
{
d_snr_est = NULL;
d_type = type;
d_nsamples = tag_nsamples;
d_count = 0;
set_alpha(alpha);
set_type(type);
// at least 1 estimator has to look back
set_history(2);
std::stringstream str;
str << name() << unique_id();
d_me = pmt::string_to_symbol(str.str());
d_key = pmt::string_to_symbol("snr");
}
mpsk_snr_est_cc_impl::~mpsk_snr_est_cc_impl()
{
if (d_snr_est)
delete d_snr_est;
}
int mpsk_snr_est_cc_impl::work(int noutput_items,
gr_vector_const_void_star& input_items,
gr_vector_void_star& output_items)
{
// This is a pass-through block; copy input to output
memcpy(output_items[0], input_items[0], noutput_items * sizeof(gr_complex));
const gr_complex* in = (const gr_complex*)input_items[0];
// Update, calculate, and issue an SNR tag every d_nsamples
int index = 0, x = 0;
int64_t nwritten = nitems_written(0);
while (index + (d_nsamples - d_count) < noutput_items) {
x = d_nsamples - d_count;
nwritten += x;
// Update the SNR estimate registers from the current input
d_snr_est->update(x, &in[index]);
// Issue a tag with the SNR data
pmt::pmt_t pmt_snr = pmt::from_double(d_snr_est->snr());
add_item_tag(0, // stream ID
nwritten, // tag's sample number
d_key, // snr key
pmt_snr, // SNR
d_me); // block src id
index += x;
d_count = 0;
}
// Keep track of remaining items and update estimators
x = noutput_items - index;
d_count += x;
d_snr_est->update(x, &in[index]);
return noutput_items;
}
double mpsk_snr_est_cc_impl::snr()
{
if (d_snr_est)
return d_snr_est->snr();
else
throw std::runtime_error("mpsk_snr_est_cc_impl:: No SNR estimator defined.");
}
snr_est_type_t mpsk_snr_est_cc_impl::type() const { return d_type; }
int mpsk_snr_est_cc_impl::tag_nsample() const { return d_nsamples; }
double mpsk_snr_est_cc_impl::alpha() const { return d_alpha; }
void mpsk_snr_est_cc_impl::set_type(snr_est_type_t t)
{
d_type = t;
if (d_snr_est)
delete d_snr_est;
switch (d_type) {
case (SNR_EST_SIMPLE):
d_snr_est = new mpsk_snr_est_simple(d_alpha);
break;
case (SNR_EST_SKEW):
d_snr_est = new mpsk_snr_est_skew(d_alpha);
break;
case (SNR_EST_M2M4):
d_snr_est = new mpsk_snr_est_m2m4(d_alpha);
break;
case (SNR_EST_SVR):
d_snr_est = new mpsk_snr_est_svr(d_alpha);
break;
default:
throw std::invalid_argument("mpsk_snr_est_cc_impl: unknown type specified.");
}
}
void mpsk_snr_est_cc_impl::set_tag_nsample(int n)
{
if (n > 0) {
d_nsamples = n;
d_count = 0; // reset state
} else
throw std::invalid_argument("mpsk_snr_est_cc_impl: tag_nsamples can't be <= 0");
}
void mpsk_snr_est_cc_impl::set_alpha(double alpha)
{
if ((alpha >= 0) && (alpha <= 1.0)) {
d_alpha = alpha;
if (d_snr_est)
d_snr_est->set_alpha(d_alpha);
} else
throw std::invalid_argument("mpsk_snr_est_cc_impl: alpha must be in [0,1]");
}
} /* namespace digital */
} /* namespace gr */
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