GNU Radio 3.6.4.1 C++ API
channel_model.h
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1 /* -*- c++ -*- */
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3  * Copyright 2009,2012 Free Software Foundation, Inc.
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22 
23 #ifndef INCLUDED_FILTER_CHANNEL_MODEL_H
24 #define INCLUDED_FILTER_CHANNEL_MODEL_H
25 
26 #include <filter/api.h>
27 #include <gr_hier_block2.h>
28 #include <gr_types.h>
29 
30 namespace gr {
31  namespace filter {
32 
33  /*!
34  * \brief channel simulator
35  * \ingroup misc_blk
36  *
37  * This block implements a basic channel model simulator that can
38  * be used to help evaluate, design, and test various signals,
39  * waveforms, and algorithms. This model allows the user to set
40  * the voltage of an AWGN noise source, a (normalized) frequency
41  * offset, a sample timing offset, and a noise seed to randomize
42  * the AWGN noise source.
43  *
44  * Multipath can be approximated in this model by using a FIR
45  * filter representation of a multipath delay profile..
46  */
47  class FILTER_API channel_model : virtual public gr_hier_block2
48  {
49  public:
50  // gr::filter::channel_model::sptr
52 
53  /*! \brief Build the channel simulator.
54  *
55  * \param noise_voltage The AWGN noise level as a voltage (to be
56  * calculated externally to meet, say, a
57  * desired SNR).
58  * \param frequency_offset The normalized frequency offset. 0 is
59  * no offset; 0.25 would be, for a digital
60  * modem, one quarter of the symbol rate.
61  * \param epsilon The sample timing offset to emulate the
62  * different rates between the sample clocks of
63  * the transmitter and receiver. 1.0 is no difference.
64  * \param taps Taps of a FIR filter to emulate a multipath delay profile.
65  * \param noise_seed A random number generator seed for the noise source.
66  */
67  static sptr make(double noise_voltage=0.0,
68  double frequency_offset=0.0,
69  double epsilon=1.0,
70  const std::vector<gr_complex> &taps=std::vector<gr_complex>(1,1),
71  double noise_seed=0);
72 
73  virtual void set_noise_voltage(double noise_voltage) = 0;
74  virtual void set_frequency_offset(double frequency_offset) = 0;
75  virtual void set_taps(const std::vector<gr_complex> &taps) = 0;
76  virtual void set_timing_offset(double epsilon) = 0;
77 
78  virtual double noise_voltage() const = 0;
79  virtual double frequency_offset() const = 0;
80  virtual std::vector<gr_complex> taps() const = 0;
81  virtual double timing_offset() const = 0;
82  };
83 
84  } /* namespace filter */
85 } /* namespace gr */
86 
87 #endif /* INCLUDED_FILTER_CHANNEL_MODEL_H */