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Tx ph.2: IntHalfBandFilter: use double buffer technique for interpolation. Use it with the UpChannelizer and increase order to 96 for better spur rejection. Moreover it is still more CPU efficient

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f4exb 2016-11-01 05:54:25 +01:00
parent b2bc5eaebd
commit bd4d224166
3 changed files with 295 additions and 19 deletions
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306
sdrbase/dsp/inthalfbandfilter.h
View File

@ -141,6 +141,51 @@ public:
}
}
// upsample by 2, return center part of original spectrum - double buffer variant
bool workInterpolateCenterDB(Sample* sampleIn, Sample *SampleOut)
{
switch(m_state)
{
case 0:
// insert sample into ring-buffer
m_samplesDB[m_ptrDB][0] = 0;
m_samplesDB[m_ptrDB][1] = 0;
m_samplesDB[m_ptrDB + m_sizeDB][0] = 0;
m_samplesDB[m_ptrDB + m_sizeDB][1] = 0;
// save result
doFIRDB(SampleOut);
// advance write-pointer
m_ptrDB = (m_ptrDB + 1) % m_sizeDB;
// next state
m_state = 1;
// tell caller we didn't consume the sample
return false;
default:
// insert sample into ring-buffer
m_samplesDB[m_ptrDB][0] = sampleIn->real();
m_samplesDB[m_ptrDB][1] = sampleIn->imag();
m_samplesDB[m_ptrDB + m_sizeDB][0] = sampleIn->real();
m_samplesDB[m_ptrDB + m_sizeDB][1] = sampleIn->imag();
// save result
doFIRDB(SampleOut);
// advance write-pointer
m_ptrDB = (m_ptrDB + 1) % m_sizeDB;
// next state
m_state = 0;
// tell caller we consumed the sample
return true;
}
}
bool workDecimateCenter(qint32 *x, qint32 *y)
{
// insert sample into ring-buffer
@ -304,7 +349,7 @@ public:
// next state
m_state = 1;
// tell caller we don't have a new sample
// tell caller we didn't consume the sample
return false;
case 1:
@ -323,7 +368,7 @@ public:
// next state
m_state = 2;
// tell caller we have a new sample
// tell caller we consumed the sample
return true;
case 2:
@ -342,7 +387,7 @@ public:
// next state
m_state = 3;
// tell caller we don't have a new sample
// tell caller we didn't consume the sample
return false;
default:
@ -361,7 +406,100 @@ public:
// next state
m_state = 0;
// tell caller we have a new sample
// tell caller we consumed the sample
return true;
}
}
// upsample by 2, from lower half of original spectrum - double buffer variant
bool workInterpolateLowerHalfDB(Sample* sampleIn, Sample *sampleOut)
{
Sample s;
switch(m_state)
{
case 0:
// insert sample into ring-buffer
m_samplesDB[m_ptrDB][0] = 0;
m_samplesDB[m_ptrDB][1] = 0;
m_samplesDB[m_ptrDB + m_sizeDB][0] = 0;
m_samplesDB[m_ptrDB + m_sizeDB][1] = 0;
// save result
doFIRDB(&s);
sampleOut->setReal(s.imag());
sampleOut->setImag(-s.real());
// advance write-pointer
m_ptrDB = (m_ptrDB + 1) % m_sizeDB;
// next state
m_state = 1;
// tell caller we didn't consume the sample
return false;
case 1:
// insert sample into ring-buffer
m_samplesDB[m_ptrDB][0] = sampleIn->real();
m_samplesDB[m_ptrDB][1] = sampleIn->imag();
m_samplesDB[m_ptrDB + m_sizeDB][0] = sampleIn->real();
m_samplesDB[m_ptrDB + m_sizeDB][1] = sampleIn->imag();
// save result
doFIRDB(&s);
sampleOut->setReal(-s.real());
sampleOut->setImag(-s.imag());
// advance write-pointer
m_ptrDB = (m_ptrDB + 1) % m_sizeDB;
// next state
m_state = 2;
// tell caller we consumed the sample
return true;
case 2:
// insert sample into ring-buffer
m_samplesDB[m_ptrDB][0] = 0;
m_samplesDB[m_ptrDB][1] = 0;
m_samplesDB[m_ptrDB + m_sizeDB][0] = 0;
m_samplesDB[m_ptrDB + m_sizeDB][1] = 0;
// save result
doFIRDB(&s);
sampleOut->setReal(-s.imag());
sampleOut->setImag(s.real());
// advance write-pointer
m_ptrDB = (m_ptrDB + 1) % m_sizeDB;
// next state
m_state = 3;
// tell caller we didn't consume the sample
return false;
default:
// insert sample into ring-buffer
m_samplesDB[m_ptrDB][0] = sampleIn->real();
m_samplesDB[m_ptrDB][1] = sampleIn->imag();
m_samplesDB[m_ptrDB + m_sizeDB][0] = sampleIn->real();
m_samplesDB[m_ptrDB + m_sizeDB][1] = sampleIn->imag();
// save result
doFIRDB(&s);
sampleOut->setReal(s.real());
sampleOut->setImag(s.imag());
// advance write-pointer
m_ptrDB = (m_ptrDB + 1) % m_sizeDB;
// next state
m_state = 0;
// tell caller we consumed the sample
return true;
}
}
@ -458,7 +596,7 @@ public:
// next state
m_state = 1;
// tell caller we don't have a new sample
// tell caller we didn't consume the sample
return false;
case 1:
@ -477,7 +615,7 @@ public:
// next state
m_state = 2;
// tell caller we have a new sample
// tell caller we consumed the sample
return true;
case 2:
@ -496,7 +634,7 @@ public:
// next state
m_state = 3;
// tell caller we don't have a new sample
// tell caller we didn't consume the sample
return false;
default:
@ -515,7 +653,100 @@ public:
// next state
m_state = 0;
// tell caller we have a new sample
// tell caller we consumed the sample
return true;
}
}
// upsample by 2, move original spectrum to upper half - double buffer variant
bool workInterpolateUpperHalfDB(Sample* sampleIn, Sample *sampleOut)
{
Sample s;
switch(m_state)
{
case 0:
// insert sample into ring-buffer
m_samplesDB[m_ptrDB][0] = 0;
m_samplesDB[m_ptrDB][1] = 0;
m_samplesDB[m_ptrDB + m_sizeDB][0] = 0;
m_samplesDB[m_ptrDB + m_sizeDB][1] = 0;
// save result
doFIRDB(&s);
sampleOut->setReal(-s.imag());
sampleOut->setImag(s.real());
// advance write-pointer
m_ptrDB = (m_ptrDB + 1) % m_sizeDB;
// next state
m_state = 1;
// tell caller we didn't consume the sample
return false;
case 1:
// insert sample into ring-buffer
m_samplesDB[m_ptrDB][0] = sampleIn->real();
m_samplesDB[m_ptrDB][1] = sampleIn->imag();
m_samplesDB[m_ptrDB + m_sizeDB][0] = sampleIn->real();
m_samplesDB[m_ptrDB + m_sizeDB][1] = sampleIn->imag();
// save result
doFIRDB(&s);
sampleOut->setReal(-s.real());
sampleOut->setImag(-s.imag());
// advance write-pointer
m_ptrDB = (m_ptrDB + 1) % m_sizeDB;
// next state
m_state = 2;
// tell caller we consumed the sample
return true;
case 2:
// insert sample into ring-buffer
m_samplesDB[m_ptrDB][0] = 0;
m_samplesDB[m_ptrDB][1] = 0;
m_samplesDB[m_ptrDB + m_sizeDB][0] = 0;
m_samplesDB[m_ptrDB + m_sizeDB][1] = 0;
// save result
doFIRDB(&s);
sampleOut->setReal(s.imag());
sampleOut->setImag(-s.real());
// advance write-pointer
m_ptrDB = (m_ptrDB + 1) % m_sizeDB;
// next state
m_state = 3;
// tell caller we didn't consume the sample
return false;
default:
// insert sample into ring-buffer
m_samplesDB[m_ptrDB][0] = sampleIn->real();
m_samplesDB[m_ptrDB][1] = sampleIn->imag();
m_samplesDB[m_ptrDB + m_sizeDB][0] = sampleIn->real();
m_samplesDB[m_ptrDB + m_sizeDB][1] = sampleIn->imag();
// save result
doFIRDB(&s);
sampleOut->setReal(s.real());
sampleOut->setImag(s.imag());
// advance write-pointer
m_ptrDB = (m_ptrDB + 1) % m_sizeDB;
// next state
m_state = 0;
// tell caller we consumed the sample
return true;
}
}
@ -549,15 +780,43 @@ public:
}
protected:
qint32 m_samples[HBFIRFilterTraits<HBFilterOrder>::hbOrder + 1][2]; // Valgrind optim (from qint16)
qint32 m_samples[HBFIRFilterTraits<HBFilterOrder>::hbOrder + 1][2]; // Valgrind optim (from qint16)
qint32 m_samplesDB[2*(HBFIRFilterTraits<HBFilterOrder>::hbOrder - 1)][2]; // double buffer technique
qint16 m_ptr;
int m_ptrDB;
int m_sizeDB;
int m_state;
void doFIRDB(Sample* sample)
{
int a = m_ptrDB + m_sizeDB; // tip pointer
int b = m_ptrDB + 1; // tail pointer
qint32 iAcc = 0;
qint32 qAcc = 0;
for (int i = 0; i < HBFIRFilterTraits<HBFilterOrder>::hbOrder / 4; i++)
{
iAcc += (m_samplesDB[a][0] + m_samplesDB[b][0]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
qAcc += (m_samplesDB[a][1] + m_samplesDB[b][1]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
a -= 2;
b += 2;
}
iAcc += ((qint32)m_samplesDB[b-1][0]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
qAcc += ((qint32)m_samplesDB[b-1][1]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
sample->setReal(iAcc >> HBFIRFilterTraits<HBFilterOrder>::hbShift -1);
sample->setImag(qAcc >> HBFIRFilterTraits<HBFilterOrder>::hbShift -1);
}
void doFIR(Sample* sample)
{
// init read-pointer
int a = HBFIRFilterTraits<HBFilterOrder>::hbMod[m_ptr + 2 + 1]; // 0 + 1
int b = HBFIRFilterTraits<HBFilterOrder>::hbMod[m_ptr + 2 - 2]; //-1 - 1
// int a = HBFIRFilterTraits<HBFilterOrder>::hbMod[m_ptr + 2 + 1]; // 0 + 1
// int b = HBFIRFilterTraits<HBFilterOrder>::hbMod[m_ptr + 2 - 2]; //-1 - 1
// ancient way:
int a = (m_ptr + 1) % (HBFIRFilterTraits<HBFilterOrder>::hbOrder + 1);
int b = (m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder - 1)) % (HBFIRFilterTraits<HBFilterOrder>::hbOrder + 1);
// go through samples in buffer
qint32 iAcc = 0;
@ -572,11 +831,16 @@ protected:
qAcc += (m_samples[a][1] + m_samples[b][1]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
// update read-pointer
a = HBFIRFilterTraits<HBFilterOrder>::hbMod[a + 2 + 2];
b = HBFIRFilterTraits<HBFilterOrder>::hbMod[b + 2 - 2];
// a = HBFIRFilterTraits<HBFilterOrder>::hbMod[a + 2 + 2];
// b = HBFIRFilterTraits<HBFilterOrder>::hbMod[b + 2 - 2];
// ancient way:
a = (a + 2) % (HBFIRFilterTraits<HBFilterOrder>::hbOrder + 1);
b = (b + (HBFIRFilterTraits<HBFilterOrder>::hbOrder - 1)) % (HBFIRFilterTraits<HBFilterOrder>::hbOrder + 1);
}
a = HBFIRFilterTraits<HBFilterOrder>::hbMod[a + 2 - 1];
// a = HBFIRFilterTraits<HBFilterOrder>::hbMod[a + 2 - 1];
// ancient way:
a = (a + HBFIRFilterTraits<HBFilterOrder>::hbOrder) % (HBFIRFilterTraits<HBFilterOrder>::hbOrder + 1);
iAcc += ((qint32)m_samples[a][0] + 1) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
qAcc += ((qint32)m_samples[a][1] + 1) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
@ -628,11 +892,23 @@ protected:
template<uint32_t HBFilterOrder>
IntHalfbandFilter<HBFilterOrder>::IntHalfbandFilter()
{
for(int i = 0; i < HBFIRFilterTraits<HBFilterOrder>::hbOrder + 1; i++) {
m_sizeDB = HBFIRFilterTraits<HBFilterOrder>::hbOrder - 1;
for (int i = 0; i < HBFIRFilterTraits<HBFilterOrder>::hbOrder + 1; i++)
{
m_samples[i][0] = 0;
m_samples[i][1] = 0;
if (i < m_sizeDB)
{
m_samplesDB[i][0] = 0;
m_samplesDB[i][1] = 0;
}
}
m_ptr = 0;
m_ptrDB = 0;
m_state = 0;
}

6
sdrbase/dsp/upchannelizer.cpp
View File

@ -207,15 +207,15 @@ UpChannelizer::FilterStage::FilterStage(Mode mode) :
{
switch(mode) {
case ModeCenter:
m_workFunction = &IntHalfbandFilter<UPCHANNELIZER_HB_FILTER_ORDER>::workInterpolateCenter;
m_workFunction = &IntHalfbandFilter<UPCHANNELIZER_HB_FILTER_ORDER>::workInterpolateCenterDB;
break;
case ModeLowerHalf:
m_workFunction = &IntHalfbandFilter<UPCHANNELIZER_HB_FILTER_ORDER>::workInterpolateLowerHalf;
m_workFunction = &IntHalfbandFilter<UPCHANNELIZER_HB_FILTER_ORDER>::workInterpolateLowerHalfDB;
break;
case ModeUpperHalf:
m_workFunction = &IntHalfbandFilter<UPCHANNELIZER_HB_FILTER_ORDER>::workInterpolateUpperHalf;
m_workFunction = &IntHalfbandFilter<UPCHANNELIZER_HB_FILTER_ORDER>::workInterpolateUpperHalfDB;
break;
}
}

2
sdrbase/dsp/upchannelizer.h
View File

@ -25,7 +25,7 @@
#include "util/message.h"
#include "dsp/inthalfbandfilter.h"
#define UPCHANNELIZER_HB_FILTER_ORDER 64
#define UPCHANNELIZER_HB_FILTER_ORDER 96
class MessageQueue;