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CMA Equalizer - work in progress

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dennis.sheirer
2015-05-12 13:15:05 +00:00
parent b728b71d61
commit 5dd4454c4c
2 changed files with 51 additions and 18 deletions
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38
src/dsp/filter/equalizer/CMAEqualizer.java
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@@ -10,7 +10,7 @@ public class CMAEqualizer implements Listener<ComplexSample>
{
private final static Logger mLog = LoggerFactory.getLogger( CMAEqualizer.class );
public static final int TAP_COUNT = 4;
public static final int TAP_COUNT = 11;
private float mModulus;
private float mMu;
@@ -27,26 +27,34 @@ public class CMAEqualizer implements Listener<ComplexSample>
{
mModulus = modulus;
mMu = mu;
mTaps[ 0 ] = new ComplexSample( 1.0f, 1.0f );
mBuffer[ 0 ] = new ComplexSample( 1.0f, 1.0f );
/* Set first tap to 1,0 as a start */
mTaps[ 0 ] = new ComplexSample( 1.0f, 0.0f );
for( int x = 1; x < TAP_COUNT; x++ )
{
mTaps[ x ] = new ComplexSample( 0.0f, 0.0f );
mBuffer[ x ] = new ComplexSample( 1.0f, 1.0f );
mBuffer[ x ] = new ComplexSample( 0.0f, 0.0f );
}
}
private void updateTaps()
private void updateTaps( ComplexSample sample )
{
/* Calculate the error. The ideal sample magnitude is unity (1.0).
* When the sample is not at unity, the error vector points in the
* opposite direction with a magnitude equal to 1 - sample magnitude.*/
mError = ComplexSample.multiply( sample, sample.norm() - mModulus );
/* Ensure we don't exceed unity */
mError.clip( 1.0f );
for( int x = 0; x < TAP_COUNT; x++ )
{
// tap -= mu * conj(sample) * error
mTaps[ x ] = ComplexSample.subtract( mTaps[ x ],
ComplexSample.multiply( ComplexSample.multiply(
mBuffer[ x ].conjugate(), mMu ), mError ) );
ComplexSample.multiply( ComplexSample.multiply(
mBuffer[ x ].conjugate(), mError ), mMu ) );
}
}
@@ -61,9 +69,7 @@ public class CMAEqualizer implements Listener<ComplexSample>
ComplexSample equalized = filter();
calculateError( equalized );
updateTaps();
updateTaps( equalized );
if( mListener != null )
{
@@ -79,8 +85,9 @@ public class CMAEqualizer implements Listener<ComplexSample>
for( int x = 0; x < TAP_COUNT; x++ )
{
sum = ComplexSample.add( sum,
ComplexSample.multiply( mBuffer[ x ], mTaps[ x ] ) );
sum = ComplexSample.add( sum, ComplexSample.multiply(
mBuffer[ ( x + mBufferPointer ) % TAP_COUNT ],
mTaps[ TAP_COUNT - x - 1 ] ) );
}
return sum;
@@ -91,9 +98,4 @@ public class CMAEqualizer implements Listener<ComplexSample>
mListener = listener;
}
private void calculateError( ComplexSample sample )
{
mError = ComplexSample.multiply( sample, sample.norm() - mModulus );
mError.clip( 1.0f );
}
}