GNU Radio C++ API Reference: burst_shaper.h Source File

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burst_shaper.h
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1/* -*- c++ -*- */
2/*
3 * Copyright 2015 Free Software Foundation, Inc.
4 *
5 * This file is part of GNU Radio
6 *
7 * SPDX-License-Identifier: GPL-3.0-or-later
8 *
9 */
10
11#ifndef BURST_SHAPER_H
12#define BURST_SHAPER_H
13
14#include <gnuradio/block.h>
15#include <gnuradio/digital/api.h>
16
17namespace gr {
18namespace digital {
19
20/*!
21 * \brief Burst shaper block for applying burst padding and ramping.
22 * \ingroup packet_operators_blk
23 *
24 * \details
25 *
26 * This block applies a configurable amount of zero padding before
27 * and/or after a burst indicated by tagged stream length tags.
28 *
29 * If phasing symbols are used, an alternating pattern of +1/-1
30 * symbols of length ceil(N/2) will be inserted before and after
31 * each burst, where N is the length of the taps vector. The ramp-
32 * up/ramp-down shape will be applied to these phasing symbols.
33 *
34 * If phasing symbols are not used, the taper will be applied
35 * directly to the head and tail of each burst.
36 *
37 * Length tags will be updated to include the length of any added
38 * zero padding or phasing symbols and will be placed at the
39 * beginning of the modified tagged stream. Any other tags found at
40 * the same offset as a length tag will also be placed at the
41 * beginning of the modified tagged stream, since these tags are
42 * assumed to be associated with the burst rather than a specific
43 * sample. For example, if "tx_time" tags are used to control
44 * bursts, their offsets should be consistent with their associated
45 * burst's length tags. Tags at other offsets will be placed with
46 * the samples on which they were found.
47 *
48 * \li input: stream of T
49 * \li output: stream of T
50 */
51template <class T>
52 class DIGITAL_API burst_shaper : virtual public block
53{
54public:
55 typedef std::shared_ptr<burst_shaper<T>> sptr;
56
57 /*!
58 * Make a burst shaper block.
59 *
60 * \param taps: vector of window taper taps; the first ceil(N/2)
61 * items are the up flank and the last ceil(N/2)
62 * items are the down flank. If taps.size() is odd,
63 * the middle tap will be used as the last item of
64 * the up flank and first item of the down flank.
65 * \param pre_padding: number of zero samples to insert before
66 * the burst.
67 * \param post_padding: number of zero samples to append after
68 * the burst.
69 * \param insert_phasing: if true, insert alternating +1/-1
70 * pattern of length ceil(N/2) before and
71 * after the burst and apply ramp up and
72 * ramp down taps, respectively, to the
73 * inserted patterns instead of the head
74 * and tail items of the burst.
75 * \param length_tag_name: the name of the tagged stream length
76 * tag key.
77 */
78 static sptr make(const std::vector<T>& taps,
79 int pre_padding = 0,
80 int post_padding = 0,
81 bool insert_phasing = false,
82 const std::string& length_tag_name = "packet_len");
83
84 /*!
85 * Returns the amount of zero padding inserted before each burst.
86 */
87 virtual int pre_padding() const = 0;
88
89 /*!
90 * Returns the amount of zero padding inserted after each burst.
91 */
92 virtual int post_padding() const = 0;
93
94 /*!
95 * Returns the total amount of zero padding and phasing symbols
96 * inserted before each burst.
97 */
98 virtual int prefix_length() const = 0;
99
100 /*!
101 * Returns the total amount of zero padding and phasing symbols
102 * inserted after each burst.
103 */
104 virtual int suffix_length() const = 0;
105};
106
107 typedef burst_shaper<float> burst_shaper_ff;
108 typedef burst_shaper<gr_complex> burst_shaper_cc;
109} // namespace digital
110} // namespace gr
111
112#endif /* BURST_SHAPER_H */
gr::block::block
block(void)
Definition gnuradio-runtime/include/gnuradio/block.h:806
gr::digital::burst_shaper
Burst shaper block for applying burst padding and ramping.
Definition burst_shaper.h:53
gr::digital::burst_shaper::suffix_length
virtual int suffix_length() const =0
gr::digital::burst_shaper::sptr
std::shared_ptr< burst_shaper< T > > sptr
Definition burst_shaper.h:55
gr::digital::burst_shaper< float >::post_padding
virtual int post_padding() const=0
gr::digital::burst_shaper::prefix_length
virtual int prefix_length() const =0
gr::digital::burst_shaper< float >::pre_padding
virtual int pre_padding() const=0
gr::digital::burst_shaper::make
static sptr make(const std::vector< T > &taps, int pre_padding=0, int post_padding=0, bool insert_phasing=false, const std::string &length_tag_name="packet_len")
block.h
api.h
DIGITAL_API
#define DIGITAL_API
Definition gr-digital/include/gnuradio/digital/api.h:18
taps
static constexpr float taps[NSTEPS+1][NTAPS]
Definition interpolator_taps.h:9
gr::digital
Definition adaptive_algorithm.h:22
gr::digital::burst_shaper_ff
burst_shaper< float > burst_shaper_ff
Definition burst_shaper.h:107
gr::digital::burst_shaper_cc
burst_shaper< gr_complex > burst_shaper_cc
Definition burst_shaper.h:108
gr
GNU Radio logging wrapper.
Definition basic_block.h:29