GitHub/sdrtrunk
1
0
Fork 0
mirror of https://github.com/DSheirer/sdrtrunk.git synced 2026-11-14 01:27:34 -05:00
Code Issues Packages Projects Releases 2 Wiki Activity

P25 Decoder - improved LSM decoding and IMBE audio decoding. Includes redesigned audio output class to handle automatic start/stop of audio playback based on availability of audio data.

Browse Source
This commit is contained in:
dennis.sheirer
2015-06-08 01:05:19 +00:00
parent 5dd4454c4c
commit 31482a1014
32 changed files with 366 additions and 432 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
src/dsp/psk/CQPSKDemodulator.java
View File

@@ -48,6 +48,7 @@ import sample.complex.ComplexSample;
import source.tuner.frequency.FrequencyChangeListener;
import buffer.FloatAveragingBuffer;
import dsp.filter.interpolator.QPSKInterpolator;
import dsp.symbol.Dibit;
/**
* Implements a CQPSK demodulator using a Gardner Detector to determine optimal
@@ -221,7 +222,7 @@ public class CQPSKDemodulator implements Instrumentable,
/* Sampling point */
private float mMu = 10.0f;
private float mGainMu = 0.1f;
private float mGainMu = 0.05f;
/* Samples per symbol */
private float mOmega = 10.0f;
@@ -314,6 +315,9 @@ public class CQPSKDemodulator implements Instrumentable,
currentSymbol.quadrature() ) * middleSymbol.quadrature();
float gardnerError = normalize( errorInphase + errorQuadrature, 1.0f );
// /*debug*/
// gardnerError = 0.0f;
/* mOmega is samples per symbol and is constrained to floating
* between +/- .005 of the nominal 10.0 samples per symbol */
@@ -331,8 +335,9 @@ public class CQPSKDemodulator implements Instrumentable,
/* Update costas loop using phase error present in current
* symbol. The symbol is rotated from star orientation to polar
* orientation to simplify error calculation */
mCostasLoop.receive(
ComplexSample.multiply( currentSymbol, POINT_45_DEGREES ) );
mCostasLoop.receive( currentSymbol );
// mCostasLoop.receive(
// ComplexSample.multiply( currentSymbol, POINT_45_DEGREES ) );
/* Dispatch the differentiated symbol to the registered listener */
if( mListener != null )
@@ -442,7 +447,8 @@ public class CQPSKDemodulator implements Instrumentable,
*/
public ComplexSample getCurrentVector()
{
return ComplexSample.fromAngle( mLoopPhase + THETA );
// return ComplexSample.fromAngle( mLoopPhase + THETA );
return ComplexSample.fromAngle( mLoopPhase );
}
@Override
@@ -450,6 +456,9 @@ public class CQPSKDemodulator implements Instrumentable,
{
/* Calculate phase error */
float phaseError = getPhaseError( sample );
Dibit d = QPSKPolarSlicer.decide( sample );
// mLog.debug( "Dibit: " + d.name() + " Error: " + phaseError );
/* Adjust for phase error */
adjust( phaseError );