GNU Radio Manual and C++ API Reference  3.7.13.4
The Free & Open Software Radio Ecosystem
iir_filter_ccc.h
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1 /* -*- c++ -*- */
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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 
29 namespace gr {
30  namespace 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  */
68  class FILTER_API iir_filter_ccc : virtual public sync_block
69  {
70  public:
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 */
Include this header to use the message passing features.
Definition: logger.h:695
IIR filter with complex input, complex output, and complex taps.
Definition: iir_filter_ccc.h:68
synchronous 1:1 input to output with historyOverride work to provide the signal processing implementa...
Definition: sync_block.h:37
boost::shared_ptr< iir_filter_ccc > sptr
Definition: iir_filter_ccc.h:72
#define FILTER_API
Definition: gr-filter/include/gnuradio/filter/api.h:30