diff options
| author | Tom Rondeau <trondeau@vt.edu> | 2013-03-18 17:35:13 -0400 |
|---|---|---|
| committer | Tom Rondeau <trondeau@vt.edu> | 2013-03-18 17:35:13 -0400 |
| commit | e0236f2bf8eb4a069736d69808432348140e576f (patch) | |
| tree | d2777ae5756e7cd8bcc656a5dc13f617e260ec1c /gr-blocks/include | |
| parent | fa058161019c44b207df3742793e2dc58b2b63dc (diff) | |
blocks: copied plateau_detector from analog to blocks.
This will be removed from gr-analog on next, but I already removed it from any GRC categories to discourage its use.
Diffstat (limited to 'gr-blocks/include')
| -rw-r--r-- | gr-blocks/include/blocks/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | gr-blocks/include/blocks/plateau_detector_fb.h | 71 |
2 files changed, 72 insertions, 0 deletions
diff --git a/gr-blocks/include/blocks/CMakeLists.txt b/gr-blocks/include/blocks/CMakeLists.txt index bb9c1c79df..631a2dff1f 100644 --- a/gr-blocks/include/blocks/CMakeLists.txt +++ b/gr-blocks/include/blocks/CMakeLists.txt @@ -164,6 +164,7 @@ install(FILES pdu.h pdu_to_tagged_stream.h peak_detector2_fb.h + plateau_detector_fb.h probe_rate.h regenerate_bb.h repack_bits_bb.h diff --git a/gr-blocks/include/blocks/plateau_detector_fb.h b/gr-blocks/include/blocks/plateau_detector_fb.h new file mode 100644 index 0000000000..041f9c1baf --- /dev/null +++ b/gr-blocks/include/blocks/plateau_detector_fb.h @@ -0,0 +1,71 @@ +/* -*- c++ -*- */ +/* + * Copyright 2012-2013 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_BLOCKS_PLATEAU_DETECTOR_FB_H +#define INCLUDED_BLOCKS_PLATEAU_DETECTOR_FB_H + +#include <blocks/api.h> +#include <gr_sync_block.h> + +namespace gr { + namespace blocks { + + /*! + * \brief Detects a plateau and marks the middle. + * + * Detect a plateau of a-priori known height. Input is a stream of floats, + * the output is a stream of bytes. Whenever a plateau is detected, the + * middle of that plateau is marked with a '1' on the output stream (all + * other samples are left at zero). + * + * You can use this in a Schmidl & Cox synchronisation algorithm to interpret + * the output of the normalized correlator. Just pass the length of the cyclic + * prefix (in samples) as the max_len parameter). + * + * Unlike the peak detectors, you must the now the absolute height of the plateau. + * Whenever the amplitude exceeds the given threshold, it starts assuming the + * presence of a plateau. + * + * An implicit hysteresis is provided by the fact that after detecting one plateau, + * it waits at least max_len samples before the next plateau can be detected. + * + * \ingroup level_blk + * + */ + class BLOCKS_API plateau_detector_fb : virtual public gr_sync_block + { + public: + typedef boost::shared_ptr<plateau_detector_fb> sptr; + + /*! + * \param max_len Maximum length of the plateau + * \param threshold Anything above this value is considered a plateau + */ + static sptr make(int max_len, float threshold=0.9); + }; + + } // namespace blocks +} // namespace gr + +#endif /* INCLUDED_BLOCKS_PLATEAU_DETECTOR_FB_H */ + |