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Diffstat (limited to 'gr-blocks/include/blocks/nco.h')
| -rw-r--r-- | gr-blocks/include/blocks/nco.h | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/gr-blocks/include/blocks/nco.h b/gr-blocks/include/blocks/nco.h new file mode 100644 index 0000000000..e6658a3572 --- /dev/null +++ b/gr-blocks/include/blocks/nco.h @@ -0,0 +1,210 @@ +/* -*- c++ -*- */ +/* + * Copyright 2002,2013 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> + +namespace gr { + namespace blocks { + + /*! + * \brief base class template for Numerically Controlled Oscillator (NCO) + * \ingroup misc + * + * Calculate sine and cosine based on the current phase. This + * class has multiple ways to calculate sin/cos and when + * requensting a range will increment the phase based on a + * frequency, which can be set using set_freq. Similar interfaces + * to the fxpt_vco can also be used to set or adjust the current + * phase. + * + * \sa fxpt_nco.h for fixed-point implementation. + */ + template<class o_type, class i_type> + class nco + { + public: + nco() : phase(0), phase_inc(0) {} + + virtual ~nco() {} + + //! Set the current phase \p angle in radians + void set_phase(double angle) { + phase = angle; + } + + //! Update the current phase in radians by \p delta_phase + 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; + } + } + + //! increment current phase angle n times + 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 + nco<o_type,i_type>::sincos(float *sinx, float *cosx) const + { + gr_sincosf(phase, sinx, cosx); + } + + template<class o_type, class i_type> + void + 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 + 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 + 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 + 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 + 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 + 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 + 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(); + } + } + + } /* namespace blocks */ +} /* namespace gr */ + +#endif /* _NCO_H_ */ |