GNU Radio Manual and C++ API Reference  3.7.13.4
The Free & Open Software Radio Ecosystem
frequency_modulator_fc.h
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1 /* -*- c++ -*- */
2 /*
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22 
23 #ifndef INCLUDED_ANALOG_FREQUENCY_MODULATOR_FC_H
24 #define INCLUDED_ANALOG_FREQUENCY_MODULATOR_FC_H
25 
26 #include <gnuradio/analog/api.h>
27 #include <gnuradio/sync_block.h>
28 
29 namespace gr {
30  namespace analog {
31 
32  /*!
33  * \brief Frequency modulator block
34  * \ingroup modulators_blk
35  *
36  * \details
37  * float input; complex baseband output
38  *
39  * Takes a real, baseband signal (x_m[n]) and output a frequency
40  * modulated signal (y[n]) according to:
41  *
42  * \f[
43  * y[n] = exp (j 2 \pi \frac{f_{\Delta}}{f_s} \sum{x[n]})
44  * \f]
45  *
46  * Where x[n] is the input sample at time n and \f$ f_{\Delta} \f$
47  * is the frequency deviation. Common values for \f$ f_{\Delta}
48  * \f$ are 5 kHz for narrowband FM channels such as for voice
49  * systems and 75 KHz for wideband FM, like audio broadcast FM
50  * stations.
51  *
52  * In this block, the input argument is \p sensitivity, not the
53  * frequency deviation. The sensitivity specifies how much the
54  * phase changes based on the new input sample. Given a maximum
55  * deviation, \f$ f_{\Delta} \f$, and sample rate \f$f_s\f$, the
56  * sensitivity is defined as:
57  *
58  * \f[
59  * k = 2 \pi \frac{f_{\Delta}}{f_s}
60  * \f]
61  */
63  {
64  public:
65  // gr::analog::frequency_modulator_fc::sptr
66  typedef boost::shared_ptr<frequency_modulator_fc> sptr;
67 
68  /*!
69  * Build a frequency modulator block.
70  *
71  * \param sensitivity radians/sample = amplitude * sensitivity
72  */
73  static sptr make(float sensitivity);
74 
75  virtual void set_sensitivity(float sens) = 0;
76  virtual float sensitivity() const = 0;
77  };
78 
79  } /* namespace analog */
80 } /* namespace gr */
81 
82 #endif /* INCLUDED_ANALOG_FREQUENCY_MODULATOR_FC_H */
Frequency modulator block.
Definition: frequency_modulator_fc.h:62
boost::shared_ptr< frequency_modulator_fc > sptr
Definition: frequency_modulator_fc.h:66
Include this header to use the message passing features.
Definition: logger.h:695
synchronous 1:1 input to output with historyOverride work to provide the signal processing implementa...
Definition: sync_block.h:37
#define ANALOG_API
Definition: gr-analog/include/gnuradio/analog/api.h:30