GNU Radio 3.5.3.2 C++ API
gr_nco.h
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1 /* -*- c++ -*- */
2 /*
3  * Copyright 2002 Free Software Foundation, Inc.
4  *
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22 #ifndef _GR_NCO_H_
23 #define _GR_NCO_H_
24 
25 
26 #include <vector>
27 #include <gr_sincos.h>
28 #include <cmath>
29 #include <gr_complex.h>
30 
31 /*!
32  * \brief base class template for Numerically Controlled Oscillator (NCO)
33  * \ingroup misc
34  */
35 
36 
37 //FIXME Eventually generalize this to fixed point
38 
39 template<class o_type, class i_type>
40 class gr_nco {
41 public:
42  gr_nco () : phase (0), phase_inc(0) {}
43 
44  virtual ~gr_nco () {}
45 
46  // radians
47  void set_phase (double angle) {
48  phase = angle;
49  }
50 
51  void adjust_phase (double delta_phase) {
52  phase += delta_phase;
53  }
54 
55 
56  // angle_rate is in radians / step
57  void set_freq (double angle_rate){
58  phase_inc = angle_rate;
59  }
60 
61  // angle_rate is a delta in radians / step
62  void adjust_freq (double delta_angle_rate)
63  {
64  phase_inc += delta_angle_rate;
65  }
66 
67  // increment current phase angle
68 
69  void step ()
70  {
71  phase += phase_inc;
72  if (fabs (phase) > M_PI){
73 
74  while (phase > M_PI)
75  phase -= 2*M_PI;
76 
77  while (phase < -M_PI)
78  phase += 2*M_PI;
79  }
80  }
81 
82  void step (int n)
83  {
84  phase += phase_inc * n;
85  if (fabs (phase) > M_PI){
86 
87  while (phase > M_PI)
88  phase -= 2*M_PI;
89 
90  while (phase < -M_PI)
91  phase += 2*M_PI;
92  }
93  }
94 
95  // units are radians / step
96  double get_phase () const { return phase; }
97  double get_freq () const { return phase_inc; }
98 
99  // compute sin and cos for current phase angle
100  void sincos (float *sinx, float *cosx) const;
101 
102  // compute cos or sin for current phase angle
103  float cos () const { return std::cos (phase); }
104  float sin () const { return std::sin (phase); }
105 
106  // compute a block at a time
107  void sin (float *output, int noutput_items, double ampl = 1.0);
108  void cos (float *output, int noutput_items, double ampl = 1.0);
109  void sincos (gr_complex *output, int noutput_items, double ampl = 1.0);
110  void sin (short *output, int noutput_items, double ampl = 1.0);
111  void cos (short *output, int noutput_items, double ampl = 1.0);
112  void sin (int *output, int noutput_items, double ampl = 1.0);
113  void cos (int *output, int noutput_items, double ampl = 1.0);
114 
115 protected:
116  double phase;
117  double phase_inc;
118 };
119 
120 template<class o_type, class i_type>
121 void
122 gr_nco<o_type,i_type>::sincos (float *sinx, float *cosx) const
123 {
124  gr_sincosf (phase, sinx, cosx);
125 }
126 
127 template<class o_type, class i_type>
128 void
129 gr_nco<o_type,i_type>::sin (float *output, int noutput_items, double ampl)
130 {
131  for (int i = 0; i < noutput_items; i++){
132  output[i] = (float)(sin () * ampl);
133  step ();
134  }
135 }
136 
137 template<class o_type, class i_type>
138 void
139 gr_nco<o_type,i_type>::cos (float *output, int noutput_items, double ampl)
140 {
141  for (int i = 0; i < noutput_items; i++){
142  output[i] = (float)(cos () * ampl);
143  step ();
144  }
145 }
146 
147 template<class o_type, class i_type>
148 void
149 gr_nco<o_type,i_type>::sin (short *output, int noutput_items, double ampl)
150 {
151  for (int i = 0; i < noutput_items; i++){
152  output[i] = (short)(sin() * ampl);
153  step ();
154  }
155 }
156 
157 template<class o_type, class i_type>
158 void
159 gr_nco<o_type,i_type>::cos (short *output, int noutput_items, double ampl)
160 {
161  for (int i = 0; i < noutput_items; i++){
162  output[i] = (short)(cos () * ampl);
163  step ();
164  }
165 }
166 
167 template<class o_type, class i_type>
168 void
169 gr_nco<o_type,i_type>::sin (int *output, int noutput_items, double ampl)
170 {
171  for (int i = 0; i < noutput_items; i++){
172  output[i] = (int)(sin () * ampl);
173  step ();
174  }
175 }
176 
177 template<class o_type, class i_type>
178 void
179 gr_nco<o_type,i_type>::cos (int *output, int noutput_items, double ampl)
180 {
181  for (int i = 0; i < noutput_items; i++){
182  output[i] = (int)(cos () * ampl);
183  step ();
184  }
185 }
186 
187 template<class o_type, class i_type>
188 void
189 gr_nco<o_type,i_type>::sincos (gr_complex *output, int noutput_items, double ampl)
190 {
191  for (int i = 0; i < noutput_items; i++){
192  float cosx, sinx;
193  sincos (&sinx, &cosx);
194  output[i] = gr_complex(cosx * ampl, sinx * ampl);
195  step ();
196  }
197 }
198 #endif /* _NCO_H_ */