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Diffstat (limited to 'gr-digital/lib/digital_ofdm_cyclic_prefixer.cc')
| -rw-r--r-- | gr-digital/lib/digital_ofdm_cyclic_prefixer.cc | 162 |
1 files changed, 0 insertions, 162 deletions
diff --git a/gr-digital/lib/digital_ofdm_cyclic_prefixer.cc b/gr-digital/lib/digital_ofdm_cyclic_prefixer.cc deleted file mode 100644 index ada5742a51..0000000000 --- a/gr-digital/lib/digital_ofdm_cyclic_prefixer.cc +++ /dev/null @@ -1,162 +0,0 @@ -/* -*- c++ -*- */ -/* - * Copyright 2004,2006,2010,2011 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 <cmath> -#include <digital_ofdm_cyclic_prefixer.h> -#include <gr_io_signature.h> - -digital_ofdm_cyclic_prefixer_sptr -digital_make_ofdm_cyclic_prefixer (size_t input_size, - size_t output_size, - int rolloff_len, - const std::string &len_tag_key) -{ - return gnuradio::get_initial_sptr(new digital_ofdm_cyclic_prefixer (input_size, - output_size, - rolloff_len, - len_tag_key)); -} - -digital_ofdm_cyclic_prefixer::digital_ofdm_cyclic_prefixer (size_t input_size, - size_t output_size, - int rolloff_len, - const std::string &len_tag_key) - : gr_tagged_stream_block ("ofdm_cyclic_prefixer", - gr_make_io_signature (1, 1, input_size*sizeof(gr_complex)), - gr_make_io_signature (1, 1, sizeof(gr_complex)), - len_tag_key), - d_fft_len(input_size), - d_output_size(output_size), - d_cp_size(output_size - input_size), - d_rolloff_len(rolloff_len), - d_up_flank((rolloff_len ? rolloff_len-1 : 0), 0), - d_down_flank((rolloff_len ? rolloff_len-1 : 0), 0), - d_delay_line(0, 0) -{ - set_relative_rate(d_output_size); - - // Flank of length 1 would just be rectangular - if (d_rolloff_len == 1) { - d_rolloff_len = 0; - } - if (d_rolloff_len) { - d_delay_line.resize(d_rolloff_len-1, 0); - if (rolloff_len > d_cp_size) { - throw std::invalid_argument("cyclic prefixer: rolloff len must smaller than the cyclic prefix."); - } - // The actual flanks are one sample shorter than d_rolloff_len, because the - // first sample of the up- and down flank is always zero and one, respectively - for (int i = 1; i < d_rolloff_len; i++) { - d_up_flank[i-1] = 0.5 * (1 + cos(M_PI * i/rolloff_len - M_PI)); - d_down_flank[i-1] = 0.5 * (1 + cos(M_PI * (rolloff_len-i)/rolloff_len - M_PI)); - } - } - - if (len_tag_key.empty()) { - set_output_multiple(d_output_size); - } else { - set_tag_propagation_policy(TPP_DONT); - } -} - -int -digital_ofdm_cyclic_prefixer::calculate_output_stream_length(const gr_vector_int &ninput_items) -{ - int nout = ninput_items[0] * d_output_size + d_delay_line.size(); - return nout; -} - -// Operates in two ways: -// - When there's a length tag name specified, operates in packet mode. -// Here, an entire OFDM frame is processed at once. The final OFDM symbol -// is postfixed with the delay line of the pulse shape. -// We manually propagate tags. -// - Otherwise, we're in freewheeling mode. Process as many OFDM symbols as -// are space for in the output buffer. The delay line is never flushed. -// Tags are propagated by the scheduler. -int -digital_ofdm_cyclic_prefixer::work (int noutput_items, - gr_vector_int &ninput_items, - gr_vector_const_void_star &input_items, - gr_vector_void_star &output_items) -{ - gr_complex *in = (gr_complex *) input_items[0]; - gr_complex *out = (gr_complex *) output_items[0]; - int symbols_to_read = 0; - - // 1) Figure out if we're in freewheeling or packet mode - if (!d_length_tag_key_str.empty()) { - symbols_to_read = ninput_items[0]; - noutput_items = symbols_to_read * d_output_size + d_delay_line.size(); - } else { - symbols_to_read = std::min(noutput_items / (int) d_output_size, ninput_items[0]); - noutput_items = symbols_to_read * d_output_size; - } - - // 2) Do the cyclic prefixing and, optionally, the pulse shaping - for (int sym_idx = 0; sym_idx < symbols_to_read; sym_idx++) { - memcpy((void *)(out + d_cp_size), (void *) in, d_fft_len * sizeof(gr_complex)); - memcpy((void *) out, (void *) (in + d_fft_len - d_cp_size), d_cp_size * sizeof(gr_complex)); - if (d_rolloff_len) { - for (int i = 0; i < d_rolloff_len-1; i++) { - out[i] = out[i] * d_up_flank[i] + d_delay_line[i]; - d_delay_line[i] = in[i] * d_down_flank[i]; - } - } - in += d_fft_len; - out += d_output_size; - } - - // 3) If we're in packet mode: - // - flush the delay line, if applicable - // - Propagate tags - if (!d_length_tag_key_str.empty()) { - if (d_rolloff_len) { - for (unsigned i = 0; i < d_delay_line.size(); i++) { - *out++ = d_delay_line[i]; - } - d_delay_line.assign(d_delay_line.size(), 0); - } - std::vector<gr_tag_t> tags; - get_tags_in_range( - tags, 0, - nitems_read(0), nitems_read(0)+symbols_to_read - ); - for (unsigned i = 0; i < tags.size(); i++) { - tags[i].offset = ((tags[i].offset - nitems_read(0)) * d_output_size) + nitems_written(0); - add_item_tag(0, - tags[i].offset, - tags[i].key, - tags[i].value - ); - } - } else { - consume_each(symbols_to_read); - } - - return noutput_items; -} - |