rotator.h

Go to the documentation of this file.

/* -*- c++ -*- */
/*
 * Copyright 2003,2008,2013 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_ROTATOR_H_
#define _GR_ROTATOR_H_

#include <gnuradio/blocks/api.h>
#include <gnuradio/gr_complex.h>
#include <volk/volk.h>
#include <cmath>

namespace gr {
namespace blocks {

class rotator
{
private:
    gr_complex d_phase;
    gr_complex d_phase_incr;
    unsigned int d_counter;

public:
    rotator() : d_phase(1), d_phase_incr(1), d_counter(0) {}

    void set_phase(gr_complex phase) { d_phase = phase / std::abs(phase); }
    void set_phase_incr(gr_complex incr) { d_phase_incr = incr / std::abs(incr); }

    gr_complex rotate(gr_complex in)
    {
        d_counter++;

        gr_complex z = in * d_phase; // rotate in by phase
        d_phase *= d_phase_incr;     // incr our phase (complex mult == add phases)

        if ((d_counter % 512) == 0)
            d_phase /=
                std::abs(d_phase); // Normalize to ensure multiplication is rotation

        return z;
    }

    void rotateN(gr_complex* out, const gr_complex* in, int n)
    {
        volk_32fc_s32fc_x2_rotator_32fc(out, in, d_phase_incr, &d_phase, n);
    }
};

} /* namespace blocks */
} /* namespace gr */

#endif /* _GR_ROTATOR_H_ */