GNU Radio Manual and C++ API Reference
3.9.1.0
The Free & Open Software Radio Ecosystem
fft_v.h
Go to the documentation of this file.
1
/* -*- c++ -*- */
2
/*
3
* Copyright 2004,2007,2008,2012,2018,2020 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 INCLUDED_FFT_FFT_V_H
12
#define INCLUDED_FFT_FFT_V_H
13
14
#include <
gnuradio/fft/api.h
>
15
#include <
gnuradio/sync_block.h
>
16
17
namespace
gr
{
18
namespace
fft {
19
20
/*!
21
* \brief Compute forward or reverse FFT. complex vector in / complex vector out.
22
* \ingroup fourier_analysis_blk
23
*
24
* The FFT operation is defined for a vector \f$x\f$ with \f$N\f$ uniformly
25
* sampled points by
26
*
27
* \f[ X(a) = \sum_{k=0}^{N-1} x(a) \cdot e^{-j 2\pi k a / N} \f]
28
*
29
* \f$ X = FFT\{x\} \f$ is the the FFT transform of \f$x(a)\f$, \f$j\f$ is
30
* the imaginary unit, \f$k\f$ and \f$a\f$ range from \f$0\f$ to \f$N-1\f$.
31
*
32
* The IFFT operation is defined for a vector \f$y\f$ with \f$N\f$
33
* uniformly sampled points by
34
*
35
* \f[ Y(b) = \sum_{k=0}^{N-1} y(b) \cdot e^{j 2\pi k b / N} \f]
36
*
37
* \f$Y = IFFT\{y\}\f$ is the the inverse FFT transform of \f$y(b)\f$,
38
* \f$j\f$ is the imaginary unit, \f$k\f$ and \f$b\f$ range from \f$0\f$ to
39
* \f$N-1\f$.
40
*
41
* \b Note, that due to the underlying FFTW library, the output of a FFT
42
* followed by an IFFT (or the other way around) will be scaled i.e.
43
* \f$FFT\{ \, IFFT\{x\} \,\} = N \cdot x \neq x\f$.
44
*
45
* \see http://www.fftw.org/faq/section3.html#whyscaled
46
*/
47
template
<
class
T,
bool
forward>
48
class
FFT_API
fft_v
:
virtual
public
sync_block
49
{
50
public
:
51
typedef
std::shared_ptr<fft_v<T, forward>>
sptr
;
52
/*! \brief
53
* \param[in] fft_size N.
54
* \param[in] window Window function to be used.
55
* \param[in] shift True moves DC carrier to the middle.
56
* \param[in] nthreads Number of underlying threads.
57
*/
58
static
sptr
make(
int
fft_size,
59
const
std::vector<float>&
window
,
60
bool
shift =
false
,
61
int
nthreads = 1);
62
63
virtual
void
set_nthreads(
int
n) = 0;
64
65
virtual
int
nthreads()
const
= 0;
66
67
virtual
bool
set_window(
const
std::vector<float>&
window
) = 0;
68
};
69
70
}
/* namespace fft */
71
}
/* namespace gr */
72
73
#endif
/* INCLUDED_FFT_FFT_V_H */
FFT_API
#define FFT_API
Definition:
gr-fft/include/gnuradio/fft/api.h:18
gr::sync_block
synchronous 1:1 input to output with history
Definition:
sync_block.h:25
api.h
sync_block.h
gr::fft::fft_v
Compute forward or reverse FFT. complex vector in / complex vector out.
Definition:
fft_v.h:48
gr::fft::fft_v::sptr
std::shared_ptr< fft_v< T, forward > > sptr
Definition:
fft_v.h:51
gr
GNU Radio logging wrapper for log4cpp library (C++ port of log4j)
Definition:
basic_block.h:29
gr::fft::window
Definition:
window.h:22
gr-fft
include
gnuradio
fft
fft_v.h
Generated by
1.8.17