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Code Issues Packages Projects Releases 2 Wiki Activity

WIP

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Denny
2017-04-01 15:10:02 -04:00
parent ffc92a8f0e
commit afae1654d5
3 changed files with 12 additions and 233 deletions
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8
src/dsp/filter/channelizer/ChannelizerViewer.java
View File

@@ -208,7 +208,7 @@ public class ChannelizerViewer extends JFrame
public class ChannelArrayPanel extends JPanel implements Listener<ComplexBuffer>
{
private PolyphaseChannelizer2 mPolyphaseChannelizer;
private ComplexPolyphaseChannelizer mPolyphaseChannelizer;
private ChannelDistributor mChannelDistributor;
public ChannelArrayPanel(float[] taps)
@@ -219,7 +219,7 @@ public class ChannelizerViewer extends JFrame
bufferSize++;
}
mPolyphaseChannelizer = new PolyphaseChannelizer2(taps, mChannelCount);
mPolyphaseChannelizer = new ComplexPolyphaseChannelizer(taps, mChannelCount, 1);
mChannelDistributor = new ChannelDistributor(bufferSize, mChannelCount);
mPolyphaseChannelizer.setChannelDistributor(mChannelDistributor);
@@ -296,8 +296,8 @@ public class ChannelizerViewer extends JFrame
public static void main(String[] args)
{
int channelCount = 100;
int channelsPerRow = 25;
int channelCount = 4;
int channelsPerRow = 4;
final ChannelizerViewer frame = new ChannelizerViewer(channelCount, channelsPerRow);

13
src/dsp/filter/channelizer/PolyphaseChannelizer2.java → src/dsp/filter/channelizer/ComplexPolyphaseChannelizer.java
View File

@@ -30,9 +30,9 @@ import sample.complex.ComplexBuffer;
import java.text.DecimalFormat;
public class PolyphaseChannelizer2 implements Listener<ComplexBuffer>
public class ComplexPolyphaseChannelizer implements Listener<ComplexBuffer>
{
private final static Logger mLog = LoggerFactory.getLogger(PolyphaseChannelizer2.class);
private final static Logger mLog = LoggerFactory.getLogger(ComplexPolyphaseChannelizer.class);
private RealFIRFilter[] mInphaseFilters;
private RealFIRFilter[] mQuadratureFilters;
@@ -57,9 +57,12 @@ public class PolyphaseChannelizer2 implements Listener<ComplexBuffer>
* @param channels - number of filters/channels to output. Since this filter bank oversamples each filter
* output, this number must be even (divisible by the oversample rate).
*/
public PolyphaseChannelizer2(float[] taps, int channels)
public ComplexPolyphaseChannelizer(float[] taps, int channels, int oversample)
{
assert(channels % 2 == 0);
if(oversample > 1 && channels % 2 != 0)
{
throw new IllegalArgumentException("Channel count must be a multiple of 2 when oversampling");
}
mChannelCount = channels;
@@ -184,7 +187,7 @@ public class PolyphaseChannelizer2 implements Listener<ComplexBuffer>
mLog.debug(sb.toString());
PolyphaseChannelizer2 channelizer = new PolyphaseChannelizer2(taps, 8);
ComplexPolyphaseChannelizer channelizer = new ComplexPolyphaseChannelizer(taps, 8, 1);
Oscillator oscillator = new Oscillator(channelCenter, 2 * sampleRate);

224
src/dsp/filter/channelizer/PolyphaseChannelizer.java
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@@ -1,224 +0,0 @@
/*******************************************************************************
* sdrtrunk
* Copyright (C) 2014-2017 Dennis Sheirer
*
* 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, either 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 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/>
*
******************************************************************************/
package dsp.filter.channelizer;
import dsp.filter.FilterFactory;
import dsp.filter.design.FilterDesignException;
import dsp.filter.fir.FIRFilterSpecification;
import dsp.filter.fir.real.RealFIRFilter;
import dsp.filter.fir.remez.RemezFIRFilterDesigner;
import dsp.mixer.Oscillator;
import org.jtransforms.fft.FloatFFT_1D;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import sample.Listener;
import sample.complex.ComplexBuffer;
import java.text.DecimalFormat;
public class PolyphaseChannelizer implements Listener<ComplexBuffer>
{
private final static Logger mLog = LoggerFactory.getLogger(PolyphaseChannelizer.class);
private RealFIRFilter[] mFilters;
private int mFilterPointer = 0;
private int mChannelCount;
private int mBlockSize;
private float[] mFilteredSamples;
private boolean mToggle = false;
private FloatFFT_1D mFFT;
private ChannelDistributor mChannelDistributor;
private DecimalFormat DECIMAL_FORMAT = new DecimalFormat("0.0000");
/**
* Creates a polyphase filter bank that divides the input frequency band into evenly spaced channels that
* are oversampled by 2x for output.
*
* @param taps of a low-pass filter designed for the inbound sample rate with a cutoff frequency
* equal to the channel bandwidth (sample rate / filters). If you need to synthesize (combine two or more
* filte outputs) a new bandwidth signal from the outputs of this filter, then the filter should be designed
* as a nyquist filter with -6 dB attenuation at the channel bandwidth cutoff frequency
*
* @param channels - number of filters/channels to output. Since this filter bank oversamples each filter
* output, this number must be even (divisible by the oversample rate).
*/
public PolyphaseChannelizer(float[] taps, int channels)
{
assert(channels % 2 == 0);
mChannelCount = channels;
initFilters(taps);
}
public void filter(float inphase, float quadrature)
{
int iIndex = 2 * mFilterPointer;
int qIndex = iIndex + 1;
mFilteredSamples[iIndex] = mFilters[iIndex].filter(inphase);
mFilteredSamples[qIndex] = mFilters[qIndex].filter(quadrature);
if(mFilterPointer == 0)
{
calculate();
mFilterPointer = mChannelCount - 1;
mToggle = !mToggle;
}
else if(mFilterPointer == mBlockSize)
{
calculate();
mFilterPointer--;
}
else
{
mFilterPointer--;
}
}
@Override
public void receive(ComplexBuffer complexBuffer)
{
float[] samples = complexBuffer.getSamples();
for(int x = 0; x < samples.length; x += 2)
{
filter(samples[x], samples[x + 1]);
}
}
private void calculate()
{
float[] samples = new float[mFilters.length];
if(mToggle)
{
System.arraycopy(mFilteredSamples, 0, samples, mChannelCount, mChannelCount);
System.arraycopy(mFilteredSamples, mChannelCount, samples, 0, mChannelCount);
}
else
{
System.arraycopy(mFilteredSamples, 0, samples, 0, mFilteredSamples.length);
}
//FFT is executed in-place where the output overwrites the input
mFFT.complexForward(samples);
dispatch(samples);
}
private void dispatch(float[] channels)
{
if(mChannelDistributor != null)
{
mChannelDistributor.receive(channels);
}
}
public void setChannelDistributor(ChannelDistributor channelDistributor)
{
mChannelDistributor = channelDistributor;
}
private double magnitude(float real, float imaginary, int fftSize)
{
return Math.sqrt(Math.pow(real, 2.0) + Math.pow(imaginary, 2.0));
}
/**
* Distributes the filter taps to each of the polyphase filters
*
* @param taps
*/
private void initFilters(float[] taps)
{
int tapCount = (int)Math.ceil((double)taps.length / (double)mChannelCount);
float[][] coefficients = new float[mChannelCount][tapCount];
for(int tap = 0; tap < tapCount; tap++)
{
for(int filter = 0; filter < mChannelCount; filter++)
{
int index = tap * mChannelCount + filter;
if(index < taps.length)
{
coefficients[filter][tap] = taps[index];
}
}
}
mFilters = new RealFIRFilter[mChannelCount * 2];
for(int filter = 0; filter < mChannelCount; filter++)
{
//Inphase filter
mFilters[2 * filter] = new RealFIRFilter(coefficients[filter], 1.0f);
//Quadrature filter
mFilters[2 * filter + 1] = new RealFIRFilter(coefficients[filter], 1.0f);
}
mFilteredSamples = new float[mFilters.length];
mFFT = new FloatFFT_1D(mChannelCount);
mBlockSize = mChannelCount / 2;
mFilterPointer = mChannelCount -1;
}
public static void main(String[] args)
{
mLog.debug("Starting ...");
int symbolRate = 4800;
int samplesPerSymbol = 2;
int symbolCount = 4;
int channels = 10;
int channelBandwidth = 12500;
int sampleRate = channels * channelBandwidth;
//Alpha is the residual channel bandwidth left over from the symbol rate and samples per symbol
float alpha = ((float)channelBandwidth / (float)(symbolRate * samplesPerSymbol)) - 1.0f;
float[] taps = FilterFactory.getRootRaisedCosine(samplesPerSymbol * channels, symbolCount, alpha);
int channelCenter = (int)(12500 * 1.5);
StringBuilder sb = new StringBuilder();
sb.append("\nPolyphase Channelizer\n");
sb.append("Sample Rate:" + sampleRate + " Channels:" + channels + " Channel Rate:" + channelBandwidth + "\n");
sb.append("Alpha: " + alpha + " Tap Count:" + taps.length + "\n");
sb.append("Channel:" + channelCenter);
mLog.debug(sb.toString());
PolyphaseChannelizer channelizer = new PolyphaseChannelizer(taps, 8);
Oscillator oscillator = new Oscillator(channelCenter, 2 * sampleRate);
for(int x = 0; x < 2000; x++)
{
channelizer.filter(oscillator.getComplex().inphase(), oscillator.getComplex().quadrature());
oscillator.rotate();
}
mLog.debug("Finished!");
}
}