sigProcLib: Remove unused functions from public interface

Also remove entirely completely unused calls. Most of these
calls have been around since OpenBTS conception. Nearly a
decade is long enough time for deprecation.

Change-Id: Ifc122aaff23414c363b4b00f99061eed8a6902d0
This commit is contained in:
Tom Tsou 2017-06-12 14:23:53 -07:00 committed by Tom Tsou
parent 1fb0ce67d8
commit 70134a01eb
2 changed files with 52 additions and 467 deletions

View File

@ -46,9 +46,9 @@ using namespace GSM;
#define CLIP_THRESH 30000.0f
/** Lookup tables for trigonometric approximation */
float cosTable[TABLESIZE+1]; // add 1 element for wrap around
float sinTable[TABLESIZE+1];
float sincTable[TABLESIZE+1];
static float cosTable[TABLESIZE+1]; // add 1 element for wrap around
static float sinTable[TABLESIZE+1];
static float sincTable[TABLESIZE+1];
/** Constants */
static const float M_PI_F = (float)M_PI;
@ -64,7 +64,7 @@ static signalVector *GMSKReverseRotation1 = NULL;
/* Precomputed fractional delay filters */
static signalVector *delayFilters[DELAYFILTS];
static Complex<float> psk8_table[8] = {
static const Complex<float> psk8_table[8] = {
Complex<float>(-0.70710678, 0.70710678),
Complex<float>( 0.0, -1.0),
Complex<float>( 0.0, 1.0),
@ -172,67 +172,7 @@ void sigProcLibDestroy()
GSMPulse4 = NULL;
}
// dB relative to 1.0.
// if > 1.0, then return 0 dB
float dB(float x) {
float arg = 1.0F;
float dB = 0.0F;
if (x >= 1.0F) return 0.0F;
if (x <= 0.0F) return -200.0F;
float prevArg = arg;
float prevdB = dB;
float stepSize = 16.0F;
float dBstepSize = 12.0F;
while (stepSize > 1.0F) {
do {
prevArg = arg;
prevdB = dB;
arg /= stepSize;
dB -= dBstepSize;
} while (arg > x);
arg = prevArg;
dB = prevdB;
stepSize *= 0.5F;
dBstepSize -= 3.0F;
}
return ((arg-x)*(dB-3.0F) + (x-arg*0.5F)*dB)/(arg - arg*0.5F);
}
// 10^(-dB/10), inverse of dB func.
float dBinv(float x) {
float arg = 1.0F;
float dB = 0.0F;
if (x >= 0.0F) return 1.0F;
if (x <= -200.0F) return 0.0F;
float prevArg = arg;
float prevdB = dB;
float stepSize = 16.0F;
float dBstepSize = 12.0F;
while (stepSize > 1.0F) {
do {
prevArg = arg;
prevdB = dB;
arg /= stepSize;
dB -= dBstepSize;
} while (dB > x);
arg = prevArg;
dB = prevdB;
stepSize *= 0.5F;
dBstepSize -= 3.0F;
}
return ((dB-x)*(arg*0.5F)+(x-(dB-3.0F))*(arg))/3.0F;
}
float vectorNorm2(const signalVector &x)
static float vectorNorm2(const signalVector &x)
{
signalVector::const_iterator xPtr = x.begin();
float Energy = 0.0;
@ -242,41 +182,6 @@ float vectorNorm2(const signalVector &x)
return Energy;
}
float vectorPower(const signalVector &x)
{
return vectorNorm2(x)/x.size();
}
/** compute cosine via lookup table */
float cosLookup(const float x)
{
float arg = x*M_1_2PI_F;
while (arg > 1.0F) arg -= 1.0F;
while (arg < 0.0F) arg += 1.0F;
const float argT = arg*((float)TABLESIZE);
const int argI = (int)argT;
const float delta = argT-argI;
const float iDelta = 1.0F-delta;
return iDelta*cosTable[argI] + delta*cosTable[argI+1];
}
/** compute sine via lookup table */
float sinLookup(const float x)
{
float arg = x*M_1_2PI_F;
while (arg > 1.0F) arg -= 1.0F;
while (arg < 0.0F) arg += 1.0F;
const float argT = arg*((float)TABLESIZE);
const int argI = (int)argT;
const float delta = argT-argI;
const float iDelta = 1.0F-delta;
return iDelta*sinTable[argI] + delta*sinTable[argI+1];
}
/** compute e^(-jx) via lookup table. */
static complex expjLookup(float x)
{
@ -401,11 +306,18 @@ static bool GMSKReverseRotate(signalVector &x, int sps)
return true;
}
signalVector *convolve(const signalVector *x,
const signalVector *h,
signalVector *y,
ConvType spanType, size_t start,
size_t len, size_t step, int offset)
/** Convolution type indicator */
enum ConvType {
START_ONLY,
NO_DELAY,
CUSTOM,
UNDEFINED,
};
static signalVector *convolve(const signalVector *x, const signalVector *h,
signalVector *y, ConvType spanType,
size_t start = 0, size_t len = 0,
size_t step = 1, int offset = 0)
{
int rc;
size_t head = 0, tail = 0;
@ -654,29 +566,6 @@ static PulseSequence *generateGSMPulse(int sps)
return pulse;
}
signalVector* reverseConjugate(signalVector *b)
{
signalVector *tmp = new signalVector(b->size());
tmp->isReal(b->isReal());
signalVector::iterator bP = b->begin();
signalVector::iterator bPEnd = b->end();
signalVector::iterator tmpP = tmp->end()-1;
if (!b->isReal()) {
while (bP < bPEnd) {
*tmpP-- = bP->conj();
bP++;
}
}
else {
while (bP < bPEnd) {
*tmpP-- = bP->real();
bP++;
}
}
return tmp;
}
bool vectorSlicer(SoftVector *x)
{
SoftVector::iterator xP = x->begin();
@ -1158,7 +1047,7 @@ static void generateSincTable()
}
}
float sinc(float x)
static float sinc(float x)
{
if (fabs(x) >= 8 * M_PI)
return 0.0;
@ -1173,7 +1062,7 @@ float sinc(float x)
* sinc function generator. The number of filters generated is specified
* by the DELAYFILTS value.
*/
void generateDelayFilters()
static void generateDelayFilters()
{
int h_len = 20;
complex *data;
@ -1268,31 +1157,8 @@ signalVector *delayVector(const signalVector *in, signalVector *out, float delay
return out;
}
signalVector *gaussianNoise(int length,
float variance,
complex mean)
static complex interpolatePoint(const signalVector &inSig, float ix)
{
signalVector *noise = new signalVector(length);
signalVector::iterator nPtr = noise->begin();
float stddev = sqrtf(variance);
while (nPtr < noise->end()) {
float u1 = (float) rand()/ (float) RAND_MAX;
while (u1==0.0)
u1 = (float) rand()/ (float) RAND_MAX;
float u2 = (float) rand()/ (float) RAND_MAX;
float arg = 2.0*M_PI*u2;
*nPtr = mean + stddev*complex(cos(arg),sin(arg))*sqrtf(-2.0*log(u1));
nPtr++;
}
return noise;
}
complex interpolatePoint(const signalVector &inSig,
float ix)
{
int start = (int) (floor(ix) - 10);
if (start < 0) start = 0;
int end = (int) (floor(ix) + 11);
@ -1332,12 +1198,9 @@ static complex fastPeakDetect(const signalVector &rxBurst, float *index)
return amp;
}
complex peakDetect(const signalVector &rxBurst,
float *peakIndex,
float *avgPwr)
static complex peakDetect(const signalVector &rxBurst,
float *peakIndex, float *avgPwr)
{
complex maxVal = 0.0;
float maxIndex = -1;
float sumPower = 0.0;
@ -1410,7 +1273,7 @@ void scaleVector(signalVector &x,
}
/** in-place conjugation */
void conjugateVector(signalVector &x)
static void conjugateVector(signalVector &x)
{
if (x.isReal()) return;
signalVector::iterator xP = x.begin();
@ -1421,37 +1284,6 @@ void conjugateVector(signalVector &x)
}
}
// in-place addition!!
bool addVector(signalVector &x,
signalVector &y)
{
signalVector::iterator xP = x.begin();
signalVector::iterator yP = y.begin();
signalVector::iterator xPEnd = x.end();
signalVector::iterator yPEnd = y.end();
while ((xP < xPEnd) && (yP < yPEnd)) {
*xP = *xP + *yP;
xP++; yP++;
}
return true;
}
// in-place multiplication!!
bool multVector(signalVector &x,
signalVector &y)
{
signalVector::iterator xP = x.begin();
signalVector::iterator yP = y.begin();
signalVector::iterator xPEnd = x.end();
signalVector::iterator yPEnd = y.end();
while ((xP < xPEnd) && (yP < yPEnd)) {
*xP = (*xP) * (*yP);
xP++; yP++;
}
return true;
}
static bool generateMidamble(int sps, int tsc)
{
bool status = true;
@ -1528,7 +1360,7 @@ release:
return status;
}
CorrelationSequence *generateEdgeMidamble(int tsc)
static CorrelationSequence *generateEdgeMidamble(int tsc)
{
complex *data = NULL;
signalVector *midamble = NULL, *_midamble = NULL;
@ -1682,6 +1514,24 @@ float energyDetect(const signalVector &rxBurst, unsigned windowLength)
return energy/windowLength;
}
static signalVector *downsampleBurst(const signalVector &burst)
{
signalVector *in, *out;
in = new signalVector(DOWNSAMPLE_IN_LEN, dnsampler->len());
out = new signalVector(DOWNSAMPLE_OUT_LEN);
memcpy(in->begin(), burst.begin(), DOWNSAMPLE_IN_LEN * 2 * sizeof(float));
if (dnsampler->rotate((float *) in->begin(), DOWNSAMPLE_IN_LEN,
(float *) out->begin(), DOWNSAMPLE_OUT_LEN) < 0) {
delete out;
out = NULL;
}
delete in;
return out;
};
/*
* Detect a burst based on correlation and peak-to-average ratio
*
@ -1816,12 +1666,8 @@ static int detectGeneralBurst(const signalVector &rxBurst,
* head: Search 8 symbols before target
* tail: Search 8 symbols + maximum expected delay
*/
int detectRACHBurst(const signalVector &burst,
float threshold,
int sps,
complex &amplitude,
float &toa,
unsigned max_toa)
static int detectRACHBurst(const signalVector &burst, float threshold, int sps,
complex &amplitude, float &toa, unsigned max_toa)
{
int rc, target, head, tail;
CorrelationSequence *sync;
@ -1845,8 +1691,8 @@ int detectRACHBurst(const signalVector &burst,
* head: Search 6 symbols before target
* tail: Search 6 symbols + maximum expected delay
*/
int analyzeTrafficBurst(const signalVector &burst, unsigned tsc, float threshold,
int sps, complex &amplitude, float &toa, unsigned max_toa)
static int analyzeTrafficBurst(const signalVector &burst, unsigned tsc, float threshold,
int sps, complex &amplitude, float &toa, unsigned max_toa)
{
int rc, target, head, tail;
CorrelationSequence *sync;
@ -1864,8 +1710,8 @@ int analyzeTrafficBurst(const signalVector &burst, unsigned tsc, float threshold
return rc;
}
int detectEdgeBurst(const signalVector &burst, unsigned tsc, float threshold,
int sps, complex &amplitude, float &toa, unsigned max_toa)
static int detectEdgeBurst(const signalVector &burst, unsigned tsc, float threshold,
int sps, complex &amplitude, float &toa, unsigned max_toa)
{
int rc, target, head, tail;
CorrelationSequence *sync;
@ -1915,41 +1761,6 @@ int detectAnyBurst(const signalVector &burst, unsigned tsc, float threshold,
return rc;
}
signalVector *downsampleBurst(const signalVector &burst)
{
signalVector *in, *out;
in = new signalVector(DOWNSAMPLE_IN_LEN, dnsampler->len());
out = new signalVector(DOWNSAMPLE_OUT_LEN);
memcpy(in->begin(), burst.begin(), DOWNSAMPLE_IN_LEN * 2 * sizeof(float));
if (dnsampler->rotate((float *) in->begin(), DOWNSAMPLE_IN_LEN,
(float *) out->begin(), DOWNSAMPLE_OUT_LEN) < 0) {
delete out;
out = NULL;
}
delete in;
return out;
};
signalVector *decimateVector(signalVector &wVector, size_t factor)
{
signalVector *dec;
if (factor <= 1)
return NULL;
dec = new signalVector(wVector.size() / factor);
dec->isReal(wVector.isReal());
signalVector::iterator itr = dec->begin();
for (size_t i = 0; i < wVector.size(); i += factor)
*itr++ = wVector[i];
return dec;
}
/*
* Soft 8-PSK decoding using Manhattan distance metric
*/
@ -2046,8 +1857,8 @@ static signalVector *demodCommon(const signalVector &burst, int sps,
* 4 SPS (if activated) to minimize distortion through the fractional
* delay filters. Symbol rotation and after always operates at 1 SPS.
*/
SoftVector *demodGmskBurst(const signalVector &rxBurst, int sps,
complex channel, float TOA)
static SoftVector *demodGmskBurst(const signalVector &rxBurst,
int sps, complex channel, float TOA)
{
SoftVector *bits;
signalVector *dec;
@ -2075,8 +1886,8 @@ SoftVector *demodGmskBurst(const signalVector &rxBurst, int sps,
* through the fractional delay filters at 1 SPS renders signal
* nearly unrecoverable.
*/
SoftVector *demodEdgeBurst(const signalVector &burst, int sps,
complex chan, float toa)
static SoftVector *demodEdgeBurst(const signalVector &burst,
int sps, complex chan, float toa)
{
SoftVector *bits;
signalVector *dec, *rot, *eq;
@ -2137,26 +1948,3 @@ fail:
sigProcLibDestroy();
return false;
}
std::string corrTypeToString(CorrType corr) {
switch (corr) {
case OFF:
return "OFF";
case TSC:
return "TSC";
case RACH:
return "RACH";
case EDGE:
return "EDGE";
case IDLE:
return "IDLE";
default:
return "unknown";
}
}
std::ostream& operator<<(std::ostream& os, CorrType corr)
{
os << corrTypeToString(corr);
return os;
}

View File

@ -25,14 +25,6 @@
#define EDGE_BURST_NBITS 444
#define EDGE_BURST_NSYMS (EDGE_BURST_NBITS / 3)
/** Convolution type indicator */
enum ConvType {
START_ONLY,
NO_DELAY,
CUSTOM,
UNDEFINED,
};
/** Codes for burst types of received bursts*/
enum CorrType{
OFF, ///< timeslot is off
@ -41,8 +33,6 @@ enum CorrType{
EDGE, ///< timeslot should contain an EDGE burst
IDLE ///< timeslot is an idle (or dummy) burst
};
std::string corrTypeToString(CorrType corr);
std::ostream& operator<<(std::ostream& os, CorrType corr);
enum SignalError {
SIGERR_NONE,
@ -61,66 +51,12 @@ enum SignalError {
*/
#define BURST_THRESH 4.0
/** Convert a linear number to a dB value */
float dB(float x);
/** Convert a dB value into a linear value */
float dBinv(float x);
/** Compute the energy of a vector */
float vectorNorm2(const signalVector &x);
/** Compute the average power of a vector */
float vectorPower(const signalVector &x);
/** Setup the signal processing library */
bool sigProcLibSetup();
/** Destroy the signal processing library */
void sigProcLibDestroy(void);
/**
Convolve two vectors.
@param a,b The vectors to be convolved.
@param c, A preallocated vector to hold the convolution result.
@param spanType The type/span of the convolution.
@return The convolution result or NULL on error.
*/
signalVector *convolve(const signalVector *a, const signalVector *b,
signalVector *c, ConvType spanType,
size_t start = 0, size_t len = 0,
size_t step = 1, int offset = 0);
/**
Frequency shift a vector.
@param y The frequency shifted vector.
@param x The vector to-be-shifted.
@param freq The digital frequency shift
@param startPhase The starting phase of the oscillator
@param finalPhase The final phase of the oscillator
@return The frequency shifted vector.
*/
signalVector* frequencyShift(signalVector *y,
signalVector *x,
float freq = 0.0,
float startPhase = 0.0,
float *finalPhase=NULL);
/**
Correlate two vectors.
@param a,b The vectors to be correlated.
@param c, A preallocated vector to hold the correlation result.
@param spanType The type/span of the correlation.
@return The correlation result.
*/
signalVector* correlate(signalVector *a,
signalVector *b,
signalVector *c,
ConvType spanType,
bool bReversedConjugated = false,
unsigned startIx = 0,
unsigned len = 0);
/** Operate soft slicer on a soft-bit vector */
bool vectorSlicer(SoftVector *x);
@ -148,45 +84,6 @@ signalVector *genRandAccessBurst(int delay, int sps, int tn);
/** Generate a dummy GSM burst - 4 or 1 SPS */
signalVector *generateDummyBurst(int sps, int tn);
/** Sinc function */
float sinc(float x);
/** Delay a vector */
signalVector *delayVector(const signalVector *in, signalVector *out, float delay);
/** Add two vectors in-place */
bool addVector(signalVector &x,
signalVector &y);
/** Multiply two vectors in-place*/
bool multVector(signalVector &x,
signalVector &y);
/** Generate a vector of gaussian noise */
signalVector *gaussianNoise(int length,
float variance = 1.0,
complex mean = complex(0.0));
/**
Given a non-integer index, interpolate a sample.
@param inSig The signal from which to interpolate.
@param ix The index.
@return The interpolated signal value.
*/
complex interpolatePoint(const signalVector &inSig,
float ix);
/**
Given a correlator output, locate the correlation peak.
@param rxBurst The correlator result.
@param peakIndex Pointer to value to receive interpolated peak index.
@param avgPower Power to value to receive mean power.
@return Peak value.
*/
complex peakDetect(const signalVector &rxBurst,
float *peakIndex,
float *avgPwr);
/**
Apply a scalar to a vector.
@param x The vector of interest.
@ -203,68 +100,6 @@ void scaleVector(signalVector &x,
*/
float energyDetect(const signalVector &rxBurst,
unsigned windowLength);
/**
RACH aka Access Burst correlator/detector.
@param burst The received GSM burst of interest.
@param threshold The threshold that the received burst's post-correlator SNR is compared against to determine validity.
@param sps The number of samples per GSM symbol.
@param amplitude The estimated amplitude of received RACH burst.
@param toa The estimate time-of-arrival of received RACH burst.
@param max_toa The maximum expected time-of-arrival
@return 1 if threshold value is reached,
negative value (-SignalError) on error,
zero (SIGERR_NONE) if no burst is detected
*/
int detectRACHBurst(const signalVector &burst,
float threshold,
int sps,
complex &amplitude,
float &toa,
unsigned max_toa);
/**
GMSK Normal Burst correlator/detector.
@param rxBurst The received GSM burst of interest.
@param tsc Midamble type (0..7) also known as TSC
@param threshold The threshold that the received burst's post-correlator SNR is compared against to determine validity.
@param sps The number of samples per GSM symbol.
@param amplitude The estimated amplitude of received TSC burst.
@param toa The estimate time-of-arrival of received TSC burst.
@param max_toa The maximum expected time-of-arrival
@return 1 if threshold value is reached,
negative value (-SignalError) on error,
zero (SIGERR_NONE) if no burst is detected
*/
int analyzeTrafficBurst(const signalVector &burst,
unsigned tsc,
float threshold,
int sps,
complex &amplitude,
float &toa,
unsigned max_toa);
/**
EDGE/8-PSK Normal Burst correlator/detector
@param burst The received GSM burst of interest
@param tsc Midamble type (0..7) also known as TSC
@param threshold The threshold that the received burst's post-correlator SNR is compared against to determine validity.
@param sps The number of samples per GSM symbol.
@param amplitude The estimated amplitude of received TSC burst.
@param toa The estimate time-of-arrival of received TSC burst.
@param max_toa The maximum expected time-of-arrival
@return 1 if threshold value is reached,
negative value (-SignalError) on error,
zero (SIGERR_NONE) if no burst is detected
*/
int detectEdgeBurst(const signalVector &burst,
unsigned tsc,
float threshold,
int sps,
complex &amplitude,
float &toa,
unsigned max_toa);
/**
8-PSK/GMSK/RACH burst detector
@param burst The received GSM burst of interest
@ -287,44 +122,6 @@ int detectAnyBurst(const signalVector &burst,
float &toa,
unsigned max_toa);
/**
Downsample 4 SPS to 1 SPS using a polyphase filterbank
@param burst Input burst of at least 624 symbols
@return Decimated signal vector of 156 symbols
*/
signalVector *downsampleBurst(const signalVector &burst);
/**
Decimate a vector.
@param wVector The vector of interest.
@param factor Decimation factor.
@return The decimated signal vector.
*/
signalVector *decimateVector(signalVector &wVector, size_t factor);
/**
Demodulates a GMSK burst using a soft-slicer.
@param rxBurst The burst to be demodulated.
@param gsmPulse The GSM pulse.
@param sps The number of samples per GSM symbol.
@param channel The amplitude estimate of the received burst.
@param TOA The time-of-arrival of the received burst.
@return The demodulated bit sequence.
*/
SoftVector *demodGmskBurst(const signalVector &rxBurst, int sps,
complex channel, float TOA);
/**
Demodulate 8-PSK EDGE burst with soft symbol ooutput
@param rxBurst The burst to be demodulated.
@param sps The number of samples per GSM symbol.
@param channel The amplitude estimate of the received burst.
@param TOA The time-of-arrival of the received burst.
@return The demodulated bit sequence.
*/
SoftVector *demodEdgeBurst(const signalVector &rxBurst, int sps,
complex channel, float TOA);
/** Demodulate burst basde on type and output soft bits */
SoftVector *demodAnyBurst(const signalVector &burst, int sps,
complex amp, float toa, CorrType type);