GNU Radio Manual and C++ API Reference 3.7.14.0
The Free & Open Software Radio Ecosystem
iir_filter_ccc.h
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1/* -*- c++ -*- */
2/*
3 * Copyright 2004,2012,2014 Free Software Foundation, Inc.
4 *
5 * This file is part of GNU Radio
6 *
7 * GNU Radio is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
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10 * any later version.
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12 * GNU Radio is distributed in the hope that it will be useful,
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14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
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18 * along with GNU Radio; see the file COPYING. If not, write to
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21 */
22
23#ifndef INCLUDED_IIR_FILTER_CCC_H
24#define INCLUDED_IIR_FILTER_CCC_H
25
26#include <gnuradio/filter/api.h>
27#include <gnuradio/sync_block.h>
28
29namespace gr {
30namespace filter {
31
32/*!
33 * \brief IIR filter with complex input, complex output, and
34 * complex taps.
35 * \ingroup filter_blk
36 *
37 * \details
38 * This filter uses the Direct Form I implementation, where \p
39 * fftaps contains the feed-forward taps, and \p fbtaps the
40 * feedback ones.
41 *
42 * \p oldstyle: The old style of the IIR filter uses feedback
43 * taps that are negative of what most definitions use (scipy
44 * and Matlab among them). This parameter keeps using the old
45 * GNU Radio style and is set to TRUE by default. When taps
46 * generated from scipy, Matlab, or gr_filter_design, use the
47 * new style by setting this to FALSE.
48 *
49 * The input and output satisfy a difference equation of the form
50 \f[
51 y[n] - \sum_{k=1}^{M} a_k y[n-k] = \sum_{k=0}^{N} b_k x[n-k]
52 \f]
53
54 \xmlonly
55 y[n] - \sum_{k=1}^{M} a_k y[n-k] = \sum_{k=0}^{N} b_k x[n-k]
56 \endxmlonly
57
58 * with the corresponding rational system function
59 \f[
60 H(z) = \frac{\sum_{k=0}^{M} b_k z^{-k}}{1 - \sum_{k=1}^{N} a_k z^{-k}}
61 \f]
62
63 \xmlonly
64 H(z) = \ frac{\sum_{k=0}^{M} b_k z^{-k}}{1 - \sum_{k=1}^{N} a_k z^{-k}}
65 \endxmlonly
66
67 */
68class FILTER_API iir_filter_ccc : virtual public sync_block
69{
70public:
71 // gr::filter::iir_filter_ccc::sptr
72 typedef boost::shared_ptr<iir_filter_ccc> sptr;
73
74 static sptr make(const std::vector<gr_complex>& fftaps,
75 const std::vector<gr_complex>& fbtaps,
76 bool oldstyle = true);
77
78 virtual void set_taps(const std::vector<gr_complex>& fftaps,
79 const std::vector<gr_complex>& fbtaps) = 0;
80};
81
82} /* namespace filter */
83} /* namespace gr */
84
85#endif /* INCLUDED_IIR_FILTER_CCC_H */
IIR filter with complex input, complex output, and complex taps.
Definition: iir_filter_ccc.h:69
virtual void set_taps(const std::vector< gr_complex > &fftaps, const std::vector< gr_complex > &fbtaps)=0
boost::shared_ptr< iir_filter_ccc > sptr
Definition: iir_filter_ccc.h:72
static sptr make(const std::vector< gr_complex > &fftaps, const std::vector< gr_complex > &fbtaps, bool oldstyle=true)
synchronous 1:1 input to output with history
Definition: sync_block.h:38
#define FILTER_API
Definition: gr-filter/include/gnuradio/filter/api.h:30
Include this header to use the message passing features.
Definition: basic_block.h:45