README change

1 files changed, 198 insertions, 0 deletions

diff --git a/gnuradio-core/src/lib/general/gr_nco.h b/gnuradio-core/src/lib/general/gr_nco.h
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+++ b/gnuradio-core/src/lib/general/gr_nco.h
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+/* -*- c++ -*- */
+/*
+ * Copyright 2002 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ *
+ * GNU Radio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+#ifndef _GR_NCO_H_
+#define _GR_NCO_H_
+
+
+#include <vector>
+#include <gr_sincos.h>
+#include <cmath>
+#include <gr_complex.h>
+
+/*!
+ * \brief base class template for Numerically Controlled Oscillator (NCO)
+ * \ingroup misc
+ */
+
+
+//FIXME  Eventually generalize this to fixed point
+
+template<class o_type, class i_type>
+class gr_nco {
+public:
+  gr_nco () : phase (0), phase_inc(0) {}
+
+  virtual ~gr_nco () {}
+
+  // radians
+  void set_phase (double angle) {
+    phase = angle;
+  }
+
+  void adjust_phase (double delta_phase) {
+    phase += delta_phase;
+  }
+
+
+  // angle_rate is in radians / step
+  void set_freq (double angle_rate){
+    phase_inc = angle_rate;
+  }
+
+  // angle_rate is a delta in radians / step
+  void adjust_freq (double delta_angle_rate)
+  {
+    phase_inc += delta_angle_rate;
+  }
+
+  // increment current phase angle
+
+  void step ()
+  {
+    phase += phase_inc;
+    if (fabs (phase) > M_PI){
+
+      while (phase > M_PI)
+	phase -= 2*M_PI;
+
+      while (phase < -M_PI)
+	phase += 2*M_PI;
+    }
+  }
+
+  void step (int n)
+  {
+    phase += phase_inc * n;
+    if (fabs (phase) > M_PI){
+
+      while (phase > M_PI)
+	phase -= 2*M_PI;
+
+      while (phase < -M_PI)
+	phase += 2*M_PI;
+    }
+  }
+
+  // units are radians / step
+  double get_phase () const { return phase; }
+  double get_freq () const { return phase_inc; }
+
+  // compute sin and cos for current phase angle
+  void sincos (float *sinx, float *cosx) const;
+
+  // compute cos or sin for current phase angle
+  float cos () const { return std::cos (phase); }
+  float sin () const { return std::sin (phase); }
+
+  // compute a block at a time
+  void sin (float *output, int noutput_items, double ampl = 1.0);
+  void cos (float *output, int noutput_items, double ampl = 1.0);
+  void sincos (gr_complex *output, int noutput_items, double ampl = 1.0);
+  void sin (short *output, int noutput_items, double ampl = 1.0);
+  void cos (short *output, int noutput_items, double ampl = 1.0);
+  void sin (int *output, int noutput_items, double ampl = 1.0);
+  void cos (int *output, int noutput_items, double ampl = 1.0);
+
+protected:
+  double phase;
+  double phase_inc;
+};
+
+template<class o_type, class i_type>
+void
+gr_nco<o_type,i_type>::sincos (float *sinx, float *cosx) const
+{
+  gr_sincosf (phase, sinx, cosx);
+}
+
+template<class o_type, class i_type>
+void
+gr_nco<o_type,i_type>::sin (float *output, int noutput_items, double ampl)
+{
+  for (int i = 0; i < noutput_items; i++){
+    output[i] = (float)(sin () * ampl);
+    step ();
+  }
+}
+
+template<class o_type, class i_type>
+void
+gr_nco<o_type,i_type>::cos (float *output, int noutput_items, double ampl)
+{
+  for (int i = 0; i < noutput_items; i++){
+    output[i] = (float)(cos () * ampl);
+    step ();
+  }
+}
+
+template<class o_type, class i_type>
+void
+gr_nco<o_type,i_type>::sin (short *output, int noutput_items, double ampl)
+{
+  for (int i = 0; i < noutput_items; i++){
+    output[i] = (short)(sin() * ampl);
+    step ();
+  }
+}
+
+template<class o_type, class i_type>
+void
+gr_nco<o_type,i_type>::cos (short *output, int noutput_items, double ampl)
+{
+  for (int i = 0; i < noutput_items; i++){
+    output[i] = (short)(cos () * ampl);
+    step ();
+  }
+}
+
+template<class o_type, class i_type>
+void
+gr_nco<o_type,i_type>::sin (int *output, int noutput_items, double ampl)
+{
+  for (int i = 0; i < noutput_items; i++){
+    output[i] = (int)(sin () * ampl);
+    step ();
+  }
+}
+
+template<class o_type, class i_type>
+void
+gr_nco<o_type,i_type>::cos (int *output, int noutput_items, double ampl)
+{
+  for (int i = 0; i < noutput_items; i++){
+    output[i] = (int)(cos () * ampl);
+    step ();
+  }
+}
+
+template<class o_type, class i_type>
+void
+gr_nco<o_type,i_type>::sincos (gr_complex *output, int noutput_items, double ampl)
+{
+  for (int i = 0; i < noutput_items; i++){
+    float cosx, sinx;
+    sincos (&sinx, &cosx);
+    output[i] = gr_complex(cosx * ampl, sinx * ampl);
+    step ();
+  }
+}
+#endif /* _NCO_H_ */