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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

This commit is contained in:
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;