void CalculateCorrections()
{
// Calculate the initial correlation value
float Gamma = 0;
float Energy = 0;
IQ Sample;
IQ ShiftedSample;
IQ PrevSample, PrevShiftedSample;
float Value;
float Diff;
int Idx = 0;
int ShiftedIdx = FFTSize;
for (; Idx < CPSize; Idx++, ShiftedIdx++)
{
Sample = DataBuffer[Idx];
ShiftedSample = DataBuffer[ShiftedIdx];
Gamma += (Sample / ShiftedSample).R2;
Energy += (Sample * Sample).R2 + (ShiftedSample * ShiftedSample).R2;
}
Value = Gamma - 0.5f * SNRValue * Energy;
Diff = Value - PrevValue;
CorrBuffer[0] = Value;
DiffFIR.Process(Diff, out DiffFIRBuffer[0]);
DiffIIR = OneMinusAlpha * DiffIIR + Alpha * Diff;
DiffIIRBuffer[0] = DiffIIR;
PrevValue = Value;
// Now, calculate all other correlations
Idx = CPSize;
ShiftedIdx = BlockSize;
for (int i = 1; i < BlockSize; i++, Idx++, ShiftedIdx++)
{
Sample = DataBuffer[Idx];
ShiftedSample = DataBuffer[ShiftedIdx];
PrevSample = DataBuffer[i - 1];
PrevShiftedSample = DataBuffer[i - 1 + FFTSize];
Gamma += (Sample / ShiftedSample).R2 -
(PrevSample / PrevShiftedSample).R2;
Energy += (Sample * Sample).R2 + (ShiftedSample * ShiftedSample).R2 -
((PrevSample * PrevSample).R2 + (PrevShiftedSample * PrevShiftedSample).R2);
Value = Gamma - 0.5f * SNRValue * Energy;
Diff = Value - PrevValue;
CorrBuffer[i] = Value;
DiffFIR.Process(Diff, out DiffFIRBuffer[i]);
DiffIIR = OneMinusAlpha * DiffIIR + Alpha * Diff;
DiffIIRBuffer[i] = DiffIIR;
PrevValue = Value;
}
}
