mirror of
https://github.com/f4exb/sdrangel.git
synced 2024-11-14 12:22:00 -05:00
94 lines
3.1 KiB
C++
94 lines
3.1 KiB
C++
///////////////////////////////////////////////////////////////////////////////////
|
|
// Copyright (C) 2018 F4EXB //
|
|
// written by Edouard Griffiths //
|
|
// //
|
|
// See: http://liquidsdr.org/blog/pll-howto/ //
|
|
// Fixed filter registers saturation //
|
|
// Added order for PSK locking. This brilliant idea actually comes from this //
|
|
// post: https://www.dsprelated.com/showthread/comp.dsp/36356-1.php //
|
|
// //
|
|
// This program 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 as version 3 of the License, or //
|
|
// (at your option) any later version. //
|
|
// //
|
|
// This program 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 V3 for more details. //
|
|
// //
|
|
// You should have received a copy of the GNU General Public License //
|
|
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
|
|
///////////////////////////////////////////////////////////////////////////////////
|
|
|
|
#include "freqlockcomplex.h"
|
|
#include <cmath>
|
|
|
|
FreqLockComplex::FreqLockComplex() :
|
|
m_a0(0.998),
|
|
m_a1(0.002),
|
|
m_y(1.0, 0.0),
|
|
m_yRe(1.0),
|
|
m_yIm(0.0),
|
|
m_freq(0.0),
|
|
m_phi(0.0),
|
|
m_phiX0(0.0),
|
|
m_phiX1(0.0),
|
|
m_y1(0.0f)
|
|
{
|
|
}
|
|
|
|
FreqLockComplex::~FreqLockComplex()
|
|
{
|
|
}
|
|
|
|
void FreqLockComplex::reset()
|
|
{
|
|
m_y.real(1.0);
|
|
m_y.imag(0.0);
|
|
m_yRe = 1.0f;
|
|
m_yIm = 0.0f;
|
|
m_freq = 0.0f;
|
|
m_phi = 0.0f;
|
|
m_phiX0 = 0.0f;
|
|
m_phiX1 = 0.0f;
|
|
m_y1 = 0.0f;
|
|
}
|
|
|
|
void FreqLockComplex::setSampleRate(unsigned int sampleRate)
|
|
{
|
|
m_a1 = 10.0f / sampleRate; // 1 - alpha
|
|
m_a0 = 1.0f - m_a1; // alpha
|
|
reset();
|
|
}
|
|
|
|
void FreqLockComplex::feed(float re, float im)
|
|
{
|
|
m_yRe = cos(m_phi);
|
|
m_yIm = sin(m_phi);
|
|
m_y.real(m_yRe);
|
|
m_y.imag(m_yIm);
|
|
std::complex<float> x(re, im);
|
|
m_phiX0 = std::arg(x);
|
|
|
|
float eF = normalizeAngle(m_phiX0 - m_phiX1);
|
|
float fHat = m_a1*eF + m_a0*m_y1;
|
|
m_y1 = fHat;
|
|
|
|
m_freq = fHat; // correct instantaneous frequency
|
|
m_phi += fHat; // advance phase with instantaneous frequency
|
|
m_phiX1 = m_phiX0;
|
|
}
|
|
|
|
float FreqLockComplex::normalizeAngle(float angle)
|
|
{
|
|
while (angle <= -M_PI) {
|
|
angle += 2.0*M_PI;
|
|
}
|
|
while (angle > M_PI) {
|
|
angle -= 2.0*M_PI;
|
|
}
|
|
return angle;
|
|
}
|
|
|