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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.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <digital_mpsk_snr_est_cc.h>
#include <gr_io_signature.h>
#include <cstdio>
digital_mpsk_snr_est_cc_sptr
digital_make_mpsk_snr_est_cc(snr_est_type_t type,
int tag_nsamples,
double alpha)
{
return gnuradio::get_initial_sptr(new digital_mpsk_snr_est_cc(
type, tag_nsamples, alpha));
}
digital_mpsk_snr_est_cc::digital_mpsk_snr_est_cc(snr_est_type_t type,
int tag_nsamples,
double alpha)
: gr_sync_block ("mpsk_snr_est_cc",
gr_make_io_signature(1, 1, sizeof(gr_complex)),
gr_make_io_signature(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::pmt_string_to_symbol(str.str());
d_key = pmt::pmt_string_to_symbol("snr");
}
digital_mpsk_snr_est_cc::~digital_mpsk_snr_est_cc()
{
if(d_snr_est)
delete d_snr_est;
}
int
digital_mpsk_snr_est_cc::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::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
digital_mpsk_snr_est_cc::snr()
{
if(d_snr_est)
return d_snr_est->snr();
else
throw std::runtime_error("digital_mpsk_snr_est_cc:: No SNR estimator defined.\n");
}
snr_est_type_t
digital_mpsk_snr_est_cc::type() const
{
return d_type;
}
int
digital_mpsk_snr_est_cc::tag_nsample() const
{
return d_nsamples;
}
double
digital_mpsk_snr_est_cc::alpha() const
{
return d_alpha;
}
void
digital_mpsk_snr_est_cc::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 digital_impl_mpsk_snr_est_simple(d_alpha);
break;
case(SNR_EST_SKEW):
d_snr_est = new digital_impl_mpsk_snr_est_skew(d_alpha);
break;
case(SNR_EST_M2M4):
d_snr_est = new digital_impl_mpsk_snr_est_m2m4(d_alpha);
break;
case(SNR_EST_SVR):
d_snr_est = new digital_impl_mpsk_snr_est_svr(d_alpha);
break;
default:
throw std::invalid_argument("digital_mpsk_snr_est_cc: unknown type specified.\n");
}
}
void
digital_mpsk_snr_est_cc::set_tag_nsample(int n)
{
if(n > 0) {
d_nsamples = n;
d_count = 0; // reset state
}
else
throw std::invalid_argument("digital_mpsk_snr_est_cc: tag_nsamples can't be <= 0\n");
}
void
digital_mpsk_snr_est_cc::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("digital_mpsk_snr_est_cc: alpha must be in [0,1]\n");
}
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