GNU Radio 2.x: gr_nco.h Source File

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# gr_nco.h

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    00001 /* -*- c++ -*- */
    00002 /*
    00003  * Copyright 2002 Free Software Foundation, Inc.
    00004  *
    00005  * This file is part of GNU Radio
    00006  *
    00007  * GNU Radio is free software; you can redistribute it and/or modify
    00008  * it under the terms of the GNU General Public License as published by
    00009  * the Free Software Foundation; either version 2, or (at your option)
    00010  * any later version.
    00011  *
    00012  * GNU Radio is distributed in the hope that it will be useful,
    00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00015  * GNU General Public License for more details.
    00016  *
    00017  * You should have received a copy of the GNU General Public License
    00018  * along with GNU Radio; see the file COPYING.  If not, write to
    00019  * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    00020  * Boston, MA 02111-1307, USA.
    00021  */
    00022 #ifndef _GR_NCO_H_
    00023 #define _GR_NCO_H_
    00024
    00025
    00026 #include <vector>
    00027 #include <gr_sincos.h>
    00028 #include <cmath>
    00029 #include <gr_complex.h>
    00030
    00036 //FIXME  Eventually generalize this to fixed point
    00037
    00038 template<class o_type, class i_type>
    00039 class gr_nco {
    00040 public:
    00041   gr_nco () : phase (0), phase_inc(0) {}
    00042
    00043   virtual ~gr_nco () {}
    00044
    00045   // radians
    00046   void set_phase (double angle) {
    00047     phase = angle;
    00048   }
    00049
    00050   void adjust_phase (double delta_phase) {
    00051     phase += delta_phase;
    00052   }
    00053
    00054
    00055   // angle_rate is in radians / step
    00056   void set_freq (double angle_rate){
    00057     phase_inc = angle_rate;
    00058   }
    00059
    00060   // angle_rate is a delta in radians / step
    00061   void adjust_freq (double delta_angle_rate)
    00062   {
    00063     phase_inc += delta_angle_rate;
    00064   }
    00065
    00066   // increment current phase angle
    00067
    00068   void step ()
    00069   {
    00070     phase += phase_inc;
    00071     if (fabs (phase) > M_PI){
    00072
    00073       while (phase > M_PI)
    00074         phase -= 2*M_PI;
    00075
    00076       while (phase < -M_PI)
    00077         phase += 2*M_PI;
    00078     }
    00079   }
    00080
    00081   void step (int n)
    00082   {
    00083     phase += phase_inc * n;
    00084     if (fabs (phase) > M_PI){
    00085
    00086       while (phase > M_PI)
    00087         phase -= 2*M_PI;
    00088
    00089       while (phase < -M_PI)
    00090         phase += 2*M_PI;
    00091     }
    00092   }
    00093
    00094   // units are radians / step
    00095   double get_phase () const { return phase; }
    00096   double get_freq () const { return phase_inc; }
    00097
    00098   // compute sin and cos for current phase angle
    00099   void sincos (float *sinx, float *cosx) const;
    00100
    00101   // compute cos or sin for current phase angle
    00102   float cos () const { return std::cos (phase); }
    00103   float sin () const { return std::sin (phase); }
    00104
    00105   // compute a block at a time
    00106   void sin (float *output, int noutput_items, double ampl = 1.0);
    00107   void cos (float *output, int noutput_items, double ampl = 1.0);
    00108   void sincos (gr_complex *output, int noutput_items, double ampl = 1.0);
    00109   void sin (short *output, int noutput_items, double ampl = 1.0);
    00110   void cos (short *output, int noutput_items, double ampl = 1.0);
    00111   void sin (int *output, int noutput_items, double ampl = 1.0);
    00112   void cos (int *output, int noutput_items, double ampl = 1.0);
    00113
    00114 protected:
    00115   double phase;
    00116   double phase_inc;
    00117 };
    00118
    00119 template<class o_type, class i_type>
    00120 void
    00121 gr_nco<o_type,i_type>::sincos (float *sinx, float *cosx) const
    00122 {
    00123   gr_sincosf (phase, sinx, cosx);
    00124 }
    00125
    00126 template<class o_type, class i_type>
    00127 void
    00128 gr_nco<o_type,i_type>::sin (float *output, int noutput_items, double ampl)
    00129 {
    00130   for (int i = 0; i < noutput_items; i++){
    00131     output[i] = (float)(sin () * ampl);
    00132     step ();
    00133   }
    00134 }
    00135
    00136 template<class o_type, class i_type>
    00137 void
    00138 gr_nco<o_type,i_type>::cos (float *output, int noutput_items, double ampl)
    00139 {
    00140   for (int i = 0; i < noutput_items; i++){
    00141     output[i] = (float)(cos () * ampl);
    00142     step ();
    00143   }
    00144 }
    00145
    00146 template<class o_type, class i_type>
    00147 void
    00148 gr_nco<o_type,i_type>::sin (short *output, int noutput_items, double ampl)
    00149 {
    00150   for (int i = 0; i < noutput_items; i++){
    00151     output[i] = (short)(sin() * ampl);
    00152     step ();
    00153   }
    00154 }
    00155
    00156 template<class o_type, class i_type>
    00157 void
    00158 gr_nco<o_type,i_type>::cos (short *output, int noutput_items, double ampl)
    00159 {
    00160   for (int i = 0; i < noutput_items; i++){
    00161     output[i] = (short)(cos () * ampl);
    00162     step ();
    00163   }
    00164 }
    00165
    00166 template<class o_type, class i_type>
    00167 void
    00168 gr_nco<o_type,i_type>::sin (int *output, int noutput_items, double ampl)
    00169 {
    00170   for (int i = 0; i < noutput_items; i++){
    00171     output[i] = (int)(sin () * ampl);
    00172     step ();
    00173   }
    00174 }
    00175
    00176 template<class o_type, class i_type>
    00177 void
    00178 gr_nco<o_type,i_type>::cos (int *output, int noutput_items, double ampl)
    00179 {
    00180   for (int i = 0; i < noutput_items; i++){
    00181     output[i] = (int)(cos () * ampl);
    00182     step ();
    00183   }
    00184 }
    00185
    00186 template<class o_type, class i_type>
    00187 void
    00188 gr_nco<o_type,i_type>::sincos (gr_complex *output, int noutput_items, double ampl)
    00189 {
    00190   for (int i = 0; i < noutput_items; i++){
    00191     float cosx, sinx;
    00192     sincos (&sinx, &cosx);
    00193     output[i] = gr_complex(cosx * ampl, sinx * ampl);
    00194     step ();
    00195   }
    00196 }
    00197 #endif /* _NCO_H_ */