diff options
Diffstat (limited to 'gr-digital/lib/digital_mpsk_snr_est_cc.cc')
| -rw-r--r-- | gr-digital/lib/digital_mpsk_snr_est_cc.cc | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/gr-digital/lib/digital_mpsk_snr_est_cc.cc b/gr-digital/lib/digital_mpsk_snr_est_cc.cc new file mode 100644 index 000000000..b5a60f0d3 --- /dev/null +++ b/gr-digital/lib/digital_mpsk_snr_est_cc.cc @@ -0,0 +1,186 @@ +/* -*- 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"); +} |