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osmo-trx/Transceiver52M/Transceiver.cpp

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/*
* Copyright 2008, 2009, 2010 Free Software Foundation, Inc.
*
* This software is distributed under the terms of the GNU Public License.
* See the COPYING file in the main directory for details.
*
* This use of this software may be subject to additional restrictions.
* See the LEGAL file in the main directory for details.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include "Transceiver.h"
#include <Logger.h>
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
using namespace GSM;
#define USB_LATENCY_INTRVL 10,0
#if USE_UHD
# define USB_LATENCY_MIN 6,7
#else
# define USB_LATENCY_MIN 1,1
#endif
/* Number of running values use in noise average */
#define NOISE_CNT 20
TransceiverState::TransceiverState()
: mRetrans(false), mNoiseLev(0.0), mNoises(NOISE_CNT)
{
for (int i = 0; i < 8; i++) {
chanType[i] = Transceiver::NONE;
fillerModulus[i] = 26;
chanResponse[i] = NULL;
DFEForward[i] = NULL;
DFEFeedback[i] = NULL;
for (int n = 0; n < 102; n++)
fillerTable[n][i] = NULL;
}
}
TransceiverState::~TransceiverState()
{
for (int i = 0; i < 8; i++) {
delete chanResponse[i];
delete DFEForward[i];
delete DFEFeedback[i];
for (int n = 0; n < 102; n++)
delete fillerTable[n][i];
}
}
void TransceiverState::init(size_t slot, signalVector *burst, bool fill)
{
signalVector *filler;
for (int i = 0; i < 102; i++) {
if (fill)
filler = new signalVector(*burst);
else
filler = new signalVector(burst->size());
fillerTable[i][slot] = filler;
}
}
Transceiver::Transceiver(int wBasePort,
const char *TRXAddress,
size_t wSPS, size_t wChans,
GSM::Time wTransmitLatency,
RadioInterface *wRadioInterface)
: mBasePort(wBasePort), mAddr(TRXAddress),
mTransmitLatency(wTransmitLatency), mClockSocket(NULL),
mRadioInterface(wRadioInterface), mSPSTx(wSPS), mSPSRx(1), mChans(wChans),
mOn(false), mTxFreq(0.0), mRxFreq(0.0), mPower(-10), mMaxExpectedDelay(0),
mTSC(0)
{
GSM::Time startTime(random() % gHyperframe,0);
mRxLowerLoopThread = new Thread(32768);
mTxLowerLoopThread = new Thread(32768);
mTransmitDeadlineClock = startTime;
mLastClockUpdateTime = startTime;
mLatencyUpdateTime = startTime;
mRadioInterface->getClock()->set(startTime);
txFullScale = mRadioInterface->fullScaleInputValue();
rxFullScale = mRadioInterface->fullScaleOutputValue();
for (int i = 0; i < 8; i++) {
for (int j = 0; j < 8; j++)
mHandover[i][j] = false;
}
}
Transceiver::~Transceiver()
{
sigProcLibDestroy();
delete mClockSocket;
for (size_t i = 0; i < mChans; i++) {
mTxPriorityQueues[i].clear();
delete mCtrlSockets[i];
delete mDataSockets[i];
}
}
bool Transceiver::init(bool filler)
{
int d_srcport, d_dstport, c_srcport, c_dstport;
signalVector *burst;
if (!mChans) {
LOG(ALERT) << "No channels assigned";
return false;
}
if (!sigProcLibSetup(mSPSTx)) {
LOG(ALERT) << "Failed to initialize signal processing library";
return false;
}
mDataSockets.resize(mChans);
mCtrlSockets.resize(mChans);
mControlServiceLoopThreads.resize(mChans);
mTxPriorityQueueServiceLoopThreads.resize(mChans);
mRxServiceLoopThreads.resize(mChans);
mTxPriorityQueues.resize(mChans);
mReceiveFIFO.resize(mChans);
mStates.resize(mChans);
/* Filler table retransmissions - support only on channel 0 */
if (filler)
mStates[0].mRetrans = true;
mClockSocket = new UDPSocket(mBasePort, mAddr.c_str(), mBasePort + 100);
for (size_t i = 0; i < mChans; i++) {
c_srcport = mBasePort + 2 * i + 1;
c_dstport = mBasePort + 2 * i + 101;
d_srcport = mBasePort + 2 * i + 2;
d_dstport = mBasePort + 2 * i + 102;
mCtrlSockets[i] = new UDPSocket(c_srcport, mAddr.c_str(), c_dstport);
mDataSockets[i] = new UDPSocket(d_srcport, mAddr.c_str(), d_dstport);
}
for (size_t i = 0; i < mChans; i++) {
mControlServiceLoopThreads[i] = new Thread(32768);
mTxPriorityQueueServiceLoopThreads[i] = new Thread(32768);
mRxServiceLoopThreads[i] = new Thread(32768);
for (size_t n = 0; n < 8; n++) {
burst = modulateBurst(gDummyBurst, 8 + (n % 4 == 0), mSPSTx);
scaleVector(*burst, txFullScale);
mStates[i].init(n, burst, filler && !i);
delete burst;
}
}
return true;
}
void Transceiver::addRadioVector(size_t chan, BitVector &bits,
int RSSI, GSM::Time &wTime)
{
signalVector *burst;
radioVector *radio_burst;
if (chan >= mTxPriorityQueues.size()) {
LOG(ALERT) << "Invalid channel " << chan;
return;
}
if (wTime.TN() > 7) {
LOG(ALERT) << "Received burst with invalid slot " << wTime.TN();
return;
}
burst = modulateBurst(bits, 8 + (wTime.TN() % 4 == 0), mSPSTx);
scaleVector(*burst, txFullScale * pow(10, -RSSI / 10));
radio_burst = new radioVector(wTime, burst);
mTxPriorityQueues[chan].write(radio_burst);
}
void Transceiver::updateFillerTable(size_t chan, radioVector *burst)
{
int TN, modFN;
TransceiverState *state = &mStates[chan];
TN = burst->getTime().TN();
modFN = burst->getTime().FN() % state->fillerModulus[TN];
delete state->fillerTable[modFN][TN];
state->fillerTable[modFN][TN] = burst->getVector();
burst->setVector(NULL);
}
void Transceiver::pushRadioVector(GSM::Time &nowTime)
{
int TN, modFN;
radioVector *burst;
TransceiverState *state;
std::vector<signalVector *> bursts(mChans);
std::vector<bool> zeros(mChans);
std::vector<bool> filler(mChans, true);
for (size_t i = 0; i < mChans; i ++) {
state = &mStates[i];
while ((burst = mTxPriorityQueues[i].getStaleBurst(nowTime))) {
LOG(NOTICE) << "dumping STALE burst in TRX->USRP interface";
if (state->mRetrans)
updateFillerTable(i, burst);
delete burst;
}
TN = nowTime.TN();
modFN = nowTime.FN() % state->fillerModulus[TN];
bursts[i] = state->fillerTable[modFN][TN];
zeros[i] = state->chanType[TN] == NONE;
if ((burst = mTxPriorityQueues[i].getCurrentBurst(nowTime))) {
bursts[i] = burst->getVector();
if (state->mRetrans) {
updateFillerTable(i, burst);
} else {
burst->setVector(NULL);
filler[i] = false;
}
delete burst;
}
}
mRadioInterface->driveTransmitRadio(bursts, zeros);
for (size_t i = 0; i < mChans; i++) {
if (!filler[i])
delete bursts[i];
}
}
void Transceiver::setModulus(size_t timeslot, size_t chan)
{
TransceiverState *state = &mStates[chan];
switch (state->chanType[timeslot]) {
case NONE:
case I:
case II:
case III:
case FILL:
state->fillerModulus[timeslot] = 26;
break;
case IV:
case VI:
case V:
state->fillerModulus[timeslot] = 51;
break;
//case V:
case VII:
state->fillerModulus[timeslot] = 102;
break;
case XIII:
state->fillerModulus[timeslot] = 52;
break;
default:
break;
}
}
Transceiver::CorrType Transceiver::expectedCorrType(GSM::Time currTime,
size_t chan)
{
TransceiverState *state = &mStates[chan];
static int tchh_subslot[26] = { 0,1,0,1,0,1,0,1,0,1,0,1,0,0,1,0,1,0,1,0,1,0,1,0,1,1 };
static int sdcch4_subslot[102] = { 3,3,3,3,0,0,2,2,2,2,3,3,3,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,0,0,2,2,2,2,
3,3,3,3,0,0,0,0,0,0,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,0,0,2,2,2,2 };
static int sdcch8_subslot[102] = { 5,5,5,5,6,6,6,6,7,7,7,7,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,6,6,6,6,7,7,7,7,0,0,0,0,
1,1,1,1,2,2,2,2,3,3,3,3,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,6,6,6,6,7,7,7,7,4,4,4,4 };
unsigned burstTN = currTime.TN();
unsigned burstFN = currTime.FN();
switch (state->chanType[burstTN]) {
case NONE:
return OFF;
break;
case FILL:
return IDLE;
break;
case I:
if (mHandover[burstTN][0])
return RACH;
return TSC;
/*if (burstFN % 26 == 25)
return IDLE;
else
return TSC;*/
break;
case II:
return TSC;
break;
case III:
if (mHandover[burstTN][tchh_subslot[burstFN % 26]])
return RACH;
return TSC;
break;
case IV:
case VI:
return RACH;
break;
case V: {
int mod51 = burstFN % 51;
if ((mod51 <= 36) && (mod51 >= 14))
return RACH;
else if ((mod51 == 4) || (mod51 == 5))
return RACH;
else if ((mod51 == 45) || (mod51 == 46))
return RACH;
else if (mHandover[burstTN][sdcch4_subslot[burstFN % 102]])
return RACH;
else
return TSC;
break;
}
case VII:
if ((burstFN % 51 <= 14) && (burstFN % 51 >= 12))
return IDLE;
else if (mHandover[burstTN][sdcch8_subslot[burstFN % 102]])
return RACH;
else
return TSC;
break;
case XIII: {
int mod52 = burstFN % 52;
if ((mod52 == 12) || (mod52 == 38))
return RACH;
else if ((mod52 == 25) || (mod52 == 51))
return IDLE;
else
return TSC;
break;
}
case LOOPBACK:
if ((burstFN % 51 <= 50) && (burstFN % 51 >=48))
return IDLE;
else
return TSC;
break;
default:
return OFF;
break;
}
}
/*
* Detect RACH synchronization sequence within a burst. No equalization
* is used or available on the RACH channel.
*/
bool Transceiver::detectRACH(TransceiverState *state,
signalVector &burst,
complex &amp, float &toa)
{
float threshold = 6.0;
return detectRACHBurst(burst, threshold, mSPSRx, &amp, &toa);
}
/*
* Detect normal burst training sequence midamble. Update equalization
* state information and channel estimate if necessary. Equalization
* is currently disabled.
*/
bool Transceiver::detectTSC(TransceiverState *state, signalVector &burst,
complex &amp, float &toa, GSM::Time &time)
{
int tn = time.TN();
float chanOffset, threshold = 5.0;
bool noise, needDFE = false, estimateChan = false;
double elapsed = time - state->chanEstimateTime[tn];
signalVector *chanResp;
/* Check equalization update state */
if (needDFE && ((elapsed > 50) || (!state->chanResponse[tn]))) {
delete state->DFEForward[tn];
delete state->DFEFeedback[tn];
state->DFEForward[tn] = NULL;
state->DFEFeedback[tn] = NULL;
estimateChan = true;
}
/* Detect normal burst midambles */
if (!analyzeTrafficBurst(burst, mTSC, threshold, mSPSRx, &amp,
&toa, mMaxExpectedDelay, estimateChan,
&chanResp, &chanOffset)) {
return false;
}
noise = state->mNoiseLev;
state->SNRestimate[tn] = amp.norm2() / (noise * noise + 1.0);
/* Set equalizer if unabled */
if (needDFE && estimateChan) {
state->chanResponse[tn] = chanResp;
state->chanRespOffset[tn] = chanOffset;
state->chanRespAmplitude[tn] = amp;
scaleVector(*chanResp, complex(1.0, 0.0) / amp);
designDFE(*chanResp, state->SNRestimate[tn],
7, &state->DFEForward[tn], &state->DFEFeedback[tn]);
state->chanEstimateTime[tn] = time;
}
return true;;
}
/*
* Demodulate GMSK burst using equalization if requested. Otherwise
* demodulate by direct rotation and soft slicing.
*/
SoftVector *Transceiver::demodulate(TransceiverState *state,
signalVector &burst, complex amp,
float toa, size_t tn, bool equalize)
{
if (equalize) {
scaleVector(burst, complex(1.0, 0.0) / amp);
return equalizeBurst(burst,
toa - state->chanRespOffset[tn],
mSPSRx,
*state->DFEForward[tn],
*state->DFEFeedback[tn]);
}
return demodulateBurst(burst, mSPSRx, amp, toa);
}
/*
* Pull bursts from the FIFO and handle according to the slot
* and burst correlation type. Equalzation is currently disabled.
*/
SoftVector *Transceiver::pullRadioVector(GSM::Time &wTime, int &RSSI,
int &timingOffset, size_t chan)
{
bool success, equalize = false;
complex amp;
float toa, pow, max = -1.0, avg = 0.0;
int max_i = -1;
signalVector *burst;
SoftVector *bits = NULL;
TransceiverState *state = &mStates[chan];
/* Blocking FIFO read */
radioVector *radio_burst = mReceiveFIFO[chan]->read();
if (!radio_burst)
return NULL;
/* Set time and determine correlation type */
GSM::Time time = radio_burst->getTime();
CorrType type = expectedCorrType(time, chan);
if ((type == OFF) || (type == IDLE)) {
delete radio_burst;
return NULL;
}
/* Select the diversity channel with highest energy */
for (size_t i = 0; i < radio_burst->chans(); i++) {
energyDetect(*radio_burst->getVector(i), 20 * mSPSRx, 0.0, &pow);
if (pow > max) {
max = pow;
max_i = i;
}
avg += pow;
}
if (max_i < 0) {
LOG(ALERT) << "Received empty burst";
delete radio_burst;
return NULL;
}
/* Average noise on diversity paths and update global levels */
burst = radio_burst->getVector(max_i);
avg = sqrt(avg / radio_burst->chans());
state->mNoiseLev = state->mNoises.avg();
/* Detect normal or RACH bursts */
if (type == TSC)
success = detectTSC(state, *burst, amp, toa, time);
else
success = detectRACH(state, *burst, amp, toa);
if (success == 0) {
state->mNoises.insert(avg);
delete radio_burst;
return NULL;
} else if (success < 0) {
if (success == -SIGERR_CLIP) {
LOG(ALERT) << "Clipping detected on RACH input";
} else {
LOG(ALERT) << "Unhandled RACH error";
}
delete radio_burst;
return NULL;
}
/* Demodulate and set output info */
if (equalize && (type != TSC))
equalize = false;
if (avg - state->mNoiseLev > 0.0)
bits = demodulate(state, *burst, amp, toa, time.TN(), equalize);
wTime = time;
RSSI = (int) floor(20.0 * log10(rxFullScale / avg));
timingOffset = (int) round(toa * 256.0 / mSPSRx);
delete radio_burst;
return bits;
}
void Transceiver::start()
{
TransceiverChannel *chan;
for (size_t i = 0; i < mControlServiceLoopThreads.size(); i++) {
chan = new TransceiverChannel(this, i);
mControlServiceLoopThreads[i]->start((void * (*)(void*))
ControlServiceLoopAdapter, (void*) chan);
}
}
void Transceiver::reset()
{
for (size_t i = 0; i < mTxPriorityQueues.size(); i++)
mTxPriorityQueues[i].clear();
}
void Transceiver::driveControl(size_t chan)
{
int MAX_PACKET_LENGTH = 100;
// check control socket
char buffer[MAX_PACKET_LENGTH];
int msgLen = -1;
buffer[0] = '\0';
msgLen = mCtrlSockets[chan]->read(buffer);
if (msgLen < 1) {
return;
}
char cmdcheck[4];
char command[MAX_PACKET_LENGTH];
char response[MAX_PACKET_LENGTH];
sscanf(buffer,"%3s %s",cmdcheck,command);
if (!chan)
writeClockInterface();
if (strcmp(cmdcheck,"CMD")!=0) {
LOG(WARNING) << "bogus message on control interface";
return;
}
LOG(INFO) << "command is " << buffer;
if (strcmp(command,"POWEROFF")==0) {
// turn off transmitter/demod
sprintf(response,"RSP POWEROFF 0");
}
else if (strcmp(command,"POWERON")==0) {
// turn on transmitter/demod
if (!mTxFreq || !mRxFreq)
sprintf(response,"RSP POWERON 1");
else {
sprintf(response,"RSP POWERON 0");
for (int i = 0; i < 8; i++) {
for (int j = 0; j < 8; j++)
mHandover[i][j] = false;
}
if (!chan && !mOn) {
// Prepare for thread start
mPower = -20;
mRadioInterface->start();
// Start radio interface threads.
mTxLowerLoopThread->start((void * (*)(void*))
TxLowerLoopAdapter,(void*) this);
mRxLowerLoopThread->start((void * (*)(void*))
RxLowerLoopAdapter,(void*) this);
for (size_t i = 0; i < mChans; i++) {
TransceiverChannel *chan = new TransceiverChannel(this, i);
mRxServiceLoopThreads[i]->start((void * (*)(void*))
RxUpperLoopAdapter, (void*) chan);
chan = new TransceiverChannel(this, i);
mTxPriorityQueueServiceLoopThreads[i]->start((void * (*)(void*))
TxUpperLoopAdapter, (void*) chan);
}
writeClockInterface();
mOn = true;
}
}
}
else if (strcmp(command,"HANDOVER")==0){
int ts=0,ss=0;
sscanf(buffer,"%3s %s %d %d",cmdcheck,command,&ts,&ss);
mHandover[ts][ss] = true;
LOG(WARNING) << "HANDOVER RACH at timeslot " << ts << " subslot " << ss;
sprintf(response,"RSP HANDOVER 0 %d %d",ts,ss);
}
else if (strcmp(command,"NOHANDOVER")==0){
int ts=0,ss=0;
sscanf(buffer,"%3s %s %d %d",cmdcheck,command,&ts,&ss);
mHandover[ts][ss] = false;
LOG(WARNING) << "NOHANDOVER at timeslot " << ts << " subslot " << ss;
sprintf(response,"RSP NOHANDOVER 0 %d %d",ts,ss);
}
else if (strcmp(command,"SETMAXDLY")==0) {
//set expected maximum time-of-arrival
int maxDelay;
sscanf(buffer,"%3s %s %d",cmdcheck,command,&maxDelay);
mMaxExpectedDelay = maxDelay; // 1 GSM symbol is approx. 1 km
sprintf(response,"RSP SETMAXDLY 0 %d",maxDelay);
}
else if (strcmp(command,"SETRXGAIN")==0) {
//set expected maximum time-of-arrival
int newGain;
sscanf(buffer,"%3s %s %d",cmdcheck,command,&newGain);
newGain = mRadioInterface->setRxGain(newGain, chan);
sprintf(response,"RSP SETRXGAIN 0 %d",newGain);
}
else if (strcmp(command,"NOISELEV")==0) {
if (mOn) {
float lev = mStates[chan].mNoiseLev;
sprintf(response,"RSP NOISELEV 0 %d",
(int) round(20.0 * log10(rxFullScale / lev)));
}
else {
sprintf(response,"RSP NOISELEV 1 0");
}
}
else if (!strcmp(command, "SETPOWER")) {
// set output power in dB
int dbPwr;
sscanf(buffer, "%3s %s %d", cmdcheck, command, &dbPwr);
if (!mOn)
sprintf(response, "RSP SETPOWER 1 %d", dbPwr);
else {
mPower = dbPwr;
mRadioInterface->setPowerAttenuation(mPower, chan);
sprintf(response, "RSP SETPOWER 0 %d", dbPwr);
}
}
else if (!strcmp(command,"ADJPOWER")) {
// adjust power in dB steps
int dbStep;
sscanf(buffer, "%3s %s %d", cmdcheck, command, &dbStep);
if (!mOn)
sprintf(response, "RSP ADJPOWER 1 %d", mPower);
else {
mPower += dbStep;
mRadioInterface->setPowerAttenuation(mPower, chan);
sprintf(response, "RSP ADJPOWER 0 %d", mPower);
}
}
else if (strcmp(command,"RXTUNE")==0) {
// tune receiver
int freqKhz;
sscanf(buffer,"%3s %s %d",cmdcheck,command,&freqKhz);
mRxFreq = freqKhz * 1e3;
if (!mRadioInterface->tuneRx(mRxFreq, chan)) {
LOG(ALERT) << "RX failed to tune";
sprintf(response,"RSP RXTUNE 1 %d",freqKhz);
}
else
sprintf(response,"RSP RXTUNE 0 %d",freqKhz);
}
else if (strcmp(command,"TXTUNE")==0) {
// tune txmtr
int freqKhz;
sscanf(buffer,"%3s %s %d",cmdcheck,command,&freqKhz);
mTxFreq = freqKhz * 1e3;
if (!mRadioInterface->tuneTx(mTxFreq, chan)) {
LOG(ALERT) << "TX failed to tune";
sprintf(response,"RSP TXTUNE 1 %d",freqKhz);
}
else
sprintf(response,"RSP TXTUNE 0 %d",freqKhz);
}
else if (!strcmp(command,"SETTSC")) {
// set TSC
unsigned TSC;
sscanf(buffer, "%3s %s %d", cmdcheck, command, &TSC);
if (mOn || (TSC<0) || (TSC>7))
sprintf(response, "RSP SETTSC 1 %d", TSC);
else if (chan && (TSC != mTSC))
sprintf(response, "RSP SETTSC 1 %d", TSC);
else {
mTSC = TSC;
generateMidamble(mSPSRx, TSC);
sprintf(response,"RSP SETTSC 0 %d", TSC);
}
}
else if (strcmp(command,"SETSLOT")==0) {
// set slot type
int corrCode;
int timeslot;
sscanf(buffer,"%3s %s %d %d",cmdcheck,command,&timeslot,&corrCode);
if ((timeslot < 0) || (timeslot > 7)) {
LOG(WARNING) << "bogus message on control interface";
sprintf(response,"RSP SETSLOT 1 %d %d",timeslot,corrCode);
return;
}
mStates[chan].chanType[timeslot] = (ChannelCombination) corrCode;
setModulus(timeslot, chan);
sprintf(response,"RSP SETSLOT 0 %d %d",timeslot,corrCode);
}
else {
LOG(WARNING) << "bogus command " << command << " on control interface.";
sprintf(response,"RSP ERR 1");
}
mCtrlSockets[chan]->write(response, strlen(response) + 1);
}
bool Transceiver::driveTxPriorityQueue(size_t chan)
{
char buffer[gSlotLen+50];
// check data socket
size_t msgLen = mDataSockets[chan]->read(buffer);
if (msgLen!=gSlotLen+1+4+1) {
LOG(ERR) << "badly formatted packet on GSM->TRX interface";
return false;
}
int timeSlot = (int) buffer[0];
uint64_t frameNum = 0;
for (int i = 0; i < 4; i++)
frameNum = (frameNum << 8) | (0x0ff & buffer[i+1]);
// periodically update GSM core clock
LOG(DEBUG) << "mTransmitDeadlineClock " << mTransmitDeadlineClock
<< " mLastClockUpdateTime " << mLastClockUpdateTime;
if (!chan) {
if (mTransmitDeadlineClock > mLastClockUpdateTime + GSM::Time(216,0))
writeClockInterface();
}
LOG(DEBUG) << "rcvd. burst at: " << GSM::Time(frameNum,timeSlot);
int RSSI = (int) buffer[5];
static BitVector newBurst(gSlotLen);
BitVector::iterator itr = newBurst.begin();
char *bufferItr = buffer+6;
while (itr < newBurst.end())
*itr++ = *bufferItr++;
GSM::Time currTime = GSM::Time(frameNum,timeSlot);
addRadioVector(chan, newBurst, RSSI, currTime);
return true;
}
void Transceiver::driveReceiveRadio()
{
if (!mRadioInterface->driveReceiveRadio())
usleep(100000);
}
void Transceiver::driveReceiveFIFO(size_t chan)
{
SoftVector *rxBurst = NULL;
int RSSI;
int TOA; // in 1/256 of a symbol
GSM::Time burstTime;
rxBurst = pullRadioVector(burstTime, RSSI, TOA, chan);
if (rxBurst) {
LOG(DEBUG) << "burst parameters: "
<< " time: " << burstTime
<< " RSSI: " << RSSI
<< " TOA: " << TOA
<< " bits: " << *rxBurst;
char burstString[gSlotLen+10];
burstString[0] = burstTime.TN();
for (int i = 0; i < 4; i++)
burstString[1+i] = (burstTime.FN() >> ((3-i)*8)) & 0x0ff;
burstString[5] = RSSI;
burstString[6] = (TOA >> 8) & 0x0ff;
burstString[7] = TOA & 0x0ff;
SoftVector::iterator burstItr = rxBurst->begin();
for (unsigned int i = 0; i < gSlotLen; i++) {
burstString[8+i] =(char) round((*burstItr++)*255.0);
}
burstString[gSlotLen+9] = '\0';
delete rxBurst;
mDataSockets[chan]->write(burstString,gSlotLen+10);
}
}
void Transceiver::driveTxFIFO()
{
/**
Features a carefully controlled latency mechanism, to
assure that transmit packets arrive at the radio/USRP
before they need to be transmitted.
Deadline clock indicates the burst that needs to be
pushed into the FIFO right NOW. If transmit queue does
not have a burst, stick in filler data.
*/
RadioClock *radioClock = (mRadioInterface->getClock());
if (mOn) {
//radioClock->wait(); // wait until clock updates
LOG(DEBUG) << "radio clock " << radioClock->get();
while (radioClock->get() + mTransmitLatency > mTransmitDeadlineClock) {
// if underrun, then we're not providing bursts to radio/USRP fast
// enough. Need to increase latency by one GSM frame.
if (mRadioInterface->getWindowType() == RadioDevice::TX_WINDOW_USRP1) {
if (mRadioInterface->isUnderrun()) {
// only update latency at the defined frame interval
if (radioClock->get() > mLatencyUpdateTime + GSM::Time(USB_LATENCY_INTRVL)) {
mTransmitLatency = mTransmitLatency + GSM::Time(1,0);
LOG(INFO) << "new latency: " << mTransmitLatency;
mLatencyUpdateTime = radioClock->get();
}
}
else {
// if underrun hasn't occurred in the last sec (216 frames) drop
// transmit latency by a timeslot
if (mTransmitLatency > GSM::Time(USB_LATENCY_MIN)) {
if (radioClock->get() > mLatencyUpdateTime + GSM::Time(216,0)) {
mTransmitLatency.decTN();
LOG(INFO) << "reduced latency: " << mTransmitLatency;
mLatencyUpdateTime = radioClock->get();
}
}
}
}
// time to push burst to transmit FIFO
pushRadioVector(mTransmitDeadlineClock);
mTransmitDeadlineClock.incTN();
}
}
radioClock->wait();
}
void Transceiver::writeClockInterface()
{
char command[50];
// FIXME -- This should be adaptive.
sprintf(command,"IND CLOCK %llu",(unsigned long long) (mTransmitDeadlineClock.FN()+2));
LOG(INFO) << "ClockInterface: sending " << command;
mClockSocket->write(command, strlen(command) + 1);
mLastClockUpdateTime = mTransmitDeadlineClock;
}
void *RxUpperLoopAdapter(TransceiverChannel *chan)
{
Transceiver *trx = chan->trx;
size_t num = chan->num;
delete chan;
trx->setPriority(0.42);
while (1) {
trx->driveReceiveFIFO(num);
pthread_testcancel();
}
return NULL;
}
void *RxLowerLoopAdapter(Transceiver *transceiver)
{
transceiver->setPriority(0.45);
while (1) {
transceiver->driveReceiveRadio();
pthread_testcancel();
}
return NULL;
}
void *TxLowerLoopAdapter(Transceiver *transceiver)
{
transceiver->setPriority(0.44);
while (1) {
transceiver->driveTxFIFO();
pthread_testcancel();
}
return NULL;
}
void *ControlServiceLoopAdapter(TransceiverChannel *chan)
{
Transceiver *trx = chan->trx;
size_t num = chan->num;
delete chan;
while (1) {
trx->driveControl(num);
pthread_testcancel();
}
return NULL;
}
void *TxUpperLoopAdapter(TransceiverChannel *chan)
{
Transceiver *trx = chan->trx;
size_t num = chan->num;
delete chan;
trx->setPriority(0.40);
while (1) {
bool stale = false;
// Flush the UDP packets until a successful transfer.
while (!trx->driveTxPriorityQueue(num)) {
stale = true;
}
if (!num && stale) {
// If a packet was stale, remind the GSM stack of the clock.
trx->writeClockInterface();
}
pthread_testcancel();
}
return NULL;
}
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