sdrangel/sdrbase/dsp/ncof.cpp

105 wiersze
3.2 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2016 Edouard Griffiths, F4EXB //
// //
// 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 <QtGlobal>
#include <stdio.h>
#include <cmath>
#include "dsp/ncof.h"
Real NCOF::m_table[NCOF::TableSize+1];
bool NCOF::m_tableInitialized = false;
float NCOF::m_tableSizeLimit = (float) NCOF::TableSize;
void NCOF::initTable()
{
if(m_tableInitialized) {
return;
}
for(int i = 0; i <= TableSize; i++) {
m_table[i] = cos((2.0 * M_PI * i) / TableSize);
}
m_tableInitialized = true;
}
NCOF::NCOF()
{
initTable();
m_phase = 0.0f;
m_phaseIncrement = 0.0f;
}
void NCOF::setFreq(Real freq, Real sampleRate)
{
m_phaseIncrement = sampleRate == 0 ? 0 : (freq * TableSize) / sampleRate;
qDebug("NCOF::setFreq: freq: %f sr: %f m_phaseIncrement: %f", freq, sampleRate, m_phaseIncrement);
}
float NCOF::next()
{
int phase = nextPhase();
return m_table[phase];
}
Complex NCOF::nextIQ()
{
int phase = nextPhase();
return Complex(m_table[phase], -m_table[(phase + TableSize / 4) % TableSize]);
}
Complex NCOF::nextIQ(float imbalance)
{
int phase = nextPhase();
int phaseQ = imbalance < 0.0 ? phase + (int) (imbalance*TableSize) : phase;
int phaseI = imbalance < 0.0 ? phase : phase + (int) (imbalance*TableSize);
return Complex(m_table[phaseI % TableSize], -m_table[(phaseQ + TableSize / 4) % TableSize]);
}
Complex NCOF::nextQI()
{
int phase = nextPhase();
return Complex(-m_table[(phase + TableSize / 4) % TableSize], m_table[phase]);
}
float NCOF::get()
{
return m_table[(int) m_phase];
}
Complex NCOF::getIQ()
{
return Complex(m_table[(int) m_phase], -m_table[((int) m_phase + TableSize / 4) % TableSize]);
}
void NCOF::getIQ(Complex& c)
{
c.real(m_table[(int) m_phase]);
c.imag(-m_table[((int) m_phase + TableSize / 4) % TableSize]);
}
Complex NCOF::getQI()
{
return Complex(-m_table[((int) m_phase + TableSize / 4) % TableSize], m_table[(int) m_phase]);
}
void NCOF::getQI(Complex& c)
{
c.imag(m_table[(int) m_phase]);
c.real(-m_table[((int) m_phase + TableSize / 4) % TableSize]);
}