GNU Radio Manual and C++ API Reference  3.7.9.2
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cma_equalizer_cc.h
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1 /* -*- c++ -*- */
2 /*
3  * Copyright 2011,2012 Free Software Foundation, Inc.
4  *
5  * This file is part of GNU Radio
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15  * GNU General Public License for more details.
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22 
23 #ifndef INCLUDED_DIGITAL_CMA_EQUALIZER_CC_H
24 #define INCLUDED_DIGITAL_CMA_EQUALIZER_CC_H
25 
26 #include <gnuradio/digital/api.h>
28 
29 namespace gr {
30  namespace digital {
31 
32  /*!
33  * \brief Implements constant modulus adaptive filter on complex stream.
34  * \ingroup equalizers_blk
35  *
36  * \details
37  * The error value and tap update equations (for p=2) can be found in:
38  *
39  * D. Godard, "Self-Recovering Equalization and Carrier Tracking
40  * in Two-Dimensional Data Communication Systems," IEEE
41  * Transactions on Communications, Vol. 28, No. 11, pp. 1867 -
42  * 1875, 1980.
43  */
45  {
46  protected:
47  virtual gr_complex error(const gr_complex &out) = 0;
48  virtual void update_tap(gr_complex &tap, const gr_complex &in) = 0;
49 
50  public:
51  // gr::digital::cma_equalizer_cc::sptr
52  typedef boost::shared_ptr<cma_equalizer_cc> sptr;
53 
54  /*!
55  * Make a CMA Equalizer block
56  *
57  * \param num_taps Numer of taps in the equalizer (channel size)
58  * \param modulus Modulus of the modulated signals
59  * \param mu Gain of the update loop
60  * \param sps Number of samples per symbol of the input signal
61  */
62  static sptr make(int num_taps, float modulus, float mu, int sps);
63 
64  virtual void set_taps(const std::vector<gr_complex> &taps) = 0;
65  virtual std::vector<gr_complex> taps() const = 0;
66  virtual float gain() const = 0;
67  virtual void set_gain(float mu) = 0;
68  virtual float modulus() const = 0;
69  virtual void set_modulus(float mod) = 0;
70  };
71 
72  } /* namespace digital */
73 } /* namespace gr */
74 
75 #endif /* INCLUDED_DIGITAL_CMA_EQUALIZER_CC_H */
#define DIGITAL_API
Definition: gr-digital/include/gnuradio/digital/api.h:30
std::complex< float > gr_complex
Definition: gr_complex.h:27
Include this header to use the message passing features.
Definition: logger.h:131
synchronous N:1 input to output with historyOverride work to provide the signal processing implementa...
Definition: sync_decimator.h:37
static const float taps[NSTEPS+1][NTAPS]
Definition: interpolator_taps.h:9
boost::shared_ptr< cma_equalizer_cc > sptr
Definition: cma_equalizer_cc.h:52
Implements constant modulus adaptive filter on complex stream.
Definition: cma_equalizer_cc.h:44