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39 - Adds P25/LSM support to the DemodulatorViewerFX application and

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adds Feed forward gain support to the C4FM DQPSK demodulator which seems
to improve output from the interpolating sample buffer at each symbol
period.  Updates the symbol timing gain for C4FM to decrease the gain a
bit since the feed forward gain is providing a better interpolated symbol.
This commit is contained in:
Denny
2018-03-24 11:03:18 -04:00
parent bfaacb309d
commit c36f6901af
16 changed files with 130 additions and 76 deletions
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10
src/main/java/io/github/dsheirer/dsp/psk/InterpolatingSampleBuffer.java
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@@ -32,7 +32,7 @@ public class InterpolatingSampleBuffer
private int mTwiceSamplesPerSymbol;
private float mSamplingPoint;
private float mSampleCounterGain = 1.0f;
private float mSampleCounterGain = 0.5f;
private float mDetectedSamplesPerSymbol;
private float mDetectedSamplesPerSymbolGain = 0.1f * mSampleCounterGain * mSampleCounterGain;
private float mMaximumSamplesPerSymbol;
@@ -43,9 +43,9 @@ public class InterpolatingSampleBuffer
/**
* Buffer to store complex sample data and produce interpolated samples.
* @param samplesPerSymbol
* @param symbolTimingGain for the symbol timing error adjustments
* @param sampleCounterGain for the symbol timing error adjustments
*/
public InterpolatingSampleBuffer(float samplesPerSymbol, float symbolTimingGain)
public InterpolatingSampleBuffer(float samplesPerSymbol, float sampleCounterGain)
{
mSamplingPoint = samplesPerSymbol;
mDetectedSamplesPerSymbol = samplesPerSymbol;
@@ -54,7 +54,9 @@ public class InterpolatingSampleBuffer
mTwiceSamplesPerSymbol = (int)Math.floor(2.0 * samplesPerSymbol);
mDelayLineInphase = new float[2 * mTwiceSamplesPerSymbol];
mDelayLineQuadrature = new float[2 * mTwiceSamplesPerSymbol];
mDetectedSamplesPerSymbolGain = symbolTimingGain * mSampleCounterGain * mSampleCounterGain;
mSampleCounterGain = sampleCounterGain;
mDetectedSamplesPerSymbolGain = 0.1f * mSampleCounterGain * mSampleCounterGain;
}
/**