diff options
| author | Johnathan Corgan <johnathan@corganlabs.com> | 2013-03-15 09:57:31 -0700 |
|---|---|---|
| committer | Johnathan Corgan <johnathan@corganlabs.com> | 2013-03-15 09:57:31 -0700 |
| commit | e965a5bb209ad46a509ccd21f393667fd69d95f9 (patch) | |
| tree | 40d683ef8f80980f12eac6cfe7f3423c49b45f87 /gr-digital/include/digital_ofdm_cyclic_prefixer.h | |
| parent | 2bf9c4cb4b0b426690f353fc1662a13e70c0d5e0 (diff) | |
| parent | 27990ca9e236931e39a830e48f0a1efe13ec085f (diff) | |
Merge branch 'ofdm-master' into ofdm-next
Added fixups for next branch changes
Conflicts:
CMakeLists.txt
gnuradio-core/src/lib/io/gr_message_sink.cc
gnuradio-core/src/lib/io/gr_message_sink.h
gnuradio-core/src/lib/io/gr_message_sink.i
gnuradio-core/src/lib/io/gr_message_source.cc
gnuradio-core/src/lib/io/gr_message_source.h
gnuradio-core/src/lib/io/gr_message_source.i
gr-blocks/CMakeLists.txt
gr-digital/CMakeLists.txt
gr-digital/grc/digital_block_tree.xml
gr-digital/include/digital/CMakeLists.txt
gr-digital/include/digital_ofdm_cyclic_prefixer.h
gr-digital/lib/CMakeLists.txt
gr-digital/lib/digital_ofdm_cyclic_prefixer.cc
gr-digital/lib/ofdm_cyclic_prefixer_impl.h
gr-digital/python/CMakeLists.txt
gr-digital/swig/CMakeLists.txt
gr-digital/swig/digital_swig.i
Diffstat (limited to 'gr-digital/include/digital_ofdm_cyclic_prefixer.h')
| -rw-r--r-- | gr-digital/include/digital_ofdm_cyclic_prefixer.h | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/gr-digital/include/digital_ofdm_cyclic_prefixer.h b/gr-digital/include/digital_ofdm_cyclic_prefixer.h new file mode 100644 index 0000000000..563a311fa3 --- /dev/null +++ b/gr-digital/include/digital_ofdm_cyclic_prefixer.h @@ -0,0 +1,95 @@ +/* -*- c++ -*- */ +/* + * Copyright 2004-2006,2011 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_OFDM_CYCLIC_PREFIXER_H +#define INCLUDED_DIGITAL_OFDM_CYCLIC_PREFIXER_H + +#include <digital/api.h> +#include <gr_tagged_stream_block.h> + +class digital_ofdm_cyclic_prefixer; +typedef boost::shared_ptr<digital_ofdm_cyclic_prefixer> digital_ofdm_cyclic_prefixer_sptr; + +/*! + * \param input_size FFT length (i.e. length of the OFDM symbols) + * \param output_size FFT length + cyclic prefix length (in samples) + * \param rolloff_len Length of the rolloff flank in samples + * \param len_tag_key For framed processing the key of the length tag + */ +DIGITAL_API digital_ofdm_cyclic_prefixer_sptr +digital_make_ofdm_cyclic_prefixer (size_t input_size, + size_t output_size, + int rolloff_len=0, + const std::string &len_tag_key=""); + + +/*! + * \brief Adds a cyclic prefix and performs pulse shaping on OFDM symbols. + * \ingroup ofdm_blk + * + * Input: OFDM symbols (in the time domain, i.e. after the IFFT). Optionally, + * entire frames can be processed. In this case, \p len_tag_key must be + * specified which holds the key of the tag that denotes how + * many OFDM symbols are in a frame. + * Output: A stream of (scalar) complex symbols, which include the cyclic prefix + * and the pulse shaping. + * Note: If complete frames are processed, and \p rolloff_len is greater + * than zero, the final OFDM symbol is followed by the delay line of + * the pulse shaping. + * + * The pulse shape is a raised cosine in the time domain. + */ +class DIGITAL_API digital_ofdm_cyclic_prefixer : public gr_tagged_stream_block +{ + friend DIGITAL_API 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); + + + protected: + digital_ofdm_cyclic_prefixer (size_t input_size, size_t output_size, int rolloff_len, const std::string &len_tag_key); + + //! Return the number of complex samples from the number of OFDM symbols (includes rolloff) + int calculate_output_stream_length(const gr_vector_int &ninput_items); + + public: + int work(int noutput_items, + gr_vector_int &ninput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items); + + private: + size_t d_fft_len; + //! FFT length + CP length in samples + size_t d_output_size; + //! Length of the cyclic prefix in samples + int d_cp_size; + //! Length of pulse rolloff in samples + int d_rolloff_len; + //! Buffers the up-flank (at the beginning of the cyclic prefix) + std::vector<float> d_up_flank; + //! Buffers the down-flank (which trails the symbol) + std::vector<float> d_down_flank; + std::vector<gr_complex> d_delay_line; // We do this explicitly to avoid outputting zeroes (i.e. no history!) +}; + +#endif /* INCLUDED_DIGITAL_OFDM_CYCLIC_PREFIXER_H */ + |