lte signal quality analysis - crony lte.pdf · anritsu lte test instrument portfolio signaling...
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Slide 1CRONY company presentation - Trebinje 2011
LTE Signal Quality AnalysisLTE Signal Quality Analysis
BTS MasterBTS Master™™, Cell Master, Cell Master™™, Spectrum Master, Spectrum Master™™
Slide 2
Anritsu LTE Test Instrument PortfolioAnritsu LTE Test Instrument Portfolio
Signaling Tester Fading Simulator Signal Analyzers
Radio Communication Analyzer
Vector Signal Generator
LTE Protocol Conformance Test System
LTE RF Conformance Test System
Rapid Test Designer(RTD)
CRONY company presentation - Trebinje 2011
Slide 3
Introducing the Next generation Anritsu Master familyIntroducing the Next generation Anritsu Master family
MT8221B
MT8222B
MT8212E
MT8213E
MS2721B
MS2722C
MS2723C
MS2724C
MS2725C
MS2726C
CRONY company presentation - Trebinje 2011
MS2712EMS2712E
MS2713EMS2713E
Slide 4
Cover all defined frequency plans and bandwidths Cover all defined frequency plans and bandwidths
Frequency bandsFrequency bands
All EAll E--UTRA Operating BandsUTRA Operating Bands
700 MHz 700 MHz –– 2700 MHz2700 MHz
Channel bandwidthsChannel bandwidths
20, 15, 10, 5, 3, 1.4 MHz20, 15, 10, 5, 3, 1.4 MHz
BTS MasterBTS Master™™ MT8221BMT8221B
Spectrum MasterSpectrum Master™™
MS2722/23/24/25/26CMS2722/23/24/25/26C
10, 5, 3, 1.4 MHz10, 5, 3, 1.4 MHz
BTS MasterBTS Master™™ MT8222AMT8222A
Cell MasterCell Master™™ MT8212/13EMT8212/13E
Spectrum MasterSpectrum Master™™ MS2712/13EMS2712/13E
Spectrum MasterSpectrum Master™™ MS2721/23/24BMS2721/23/24B
LTE Bandwidth SelectionLTE Bandwidth Selection
CRONY company presentation - Trebinje 2011
Slide 5
A Family of LTE Signal Quality AnalyzersA Family of LTE Signal Quality Analyzers
RF Quality AnalyzerRF Quality Analyzer
RF MeasurementsRF Measurements
Modulation Quality AnalyzerModulation Quality Analyzer
Modulation MeasurementsModulation Measurements
DL Coverage Quality AnalyzerDL Coverage Quality Analyzer
OverOver--thethe--Air MeasurementsAir Measurements
Pass/Fail AnalyzerPass/Fail Analyzer
LTE Measurement SummaryLTE Measurement SummaryLTE Measurement SummaryLTE Measurement Summary
CRONY company presentation - Trebinje 2011
Slide 6
LTE RF Quality MeasurementsLTE RF Quality Measurements
Channel SpectrumChannel Spectrum
Channel PowerChannel Power
Occupied BandwidthOccupied Bandwidth
ACLRACLR
Spectral Emission Mask (SEM)Spectral Emission Mask (SEM)
RF Measurement SummaryRF Measurement Summary
RF Measurement SummaryRF Measurement Summary
CRONY company presentation - Trebinje 2011
Slide 7
LTE Modulation Quality MeasurementsLTE Modulation Quality Measurements
ConstellationConstellation
QPSK, 16 QAM, 64 QAMQPSK, 16 QAM, 64 QAM
Control Channel PowerControl Channel Power
Modulation SummaryModulation Summary
Modulation Measurement SummaryModulation Measurement Summary
CRONY company presentation - Trebinje 2011
Slide 8
LTE Downlink Coverage Quality MeasurementsLTE Downlink Coverage Quality Measurements
ScannerScanner
Six Sync Signal Power LevelsSix Sync Signal Power Levels
Cell IDCell ID
Sector IDSector ID
Group IDGroup ID
DominanceDominance
Auto SaveAuto Save
OTA Scanner MeasurementsOTA Scanner Measurements
CRONY company presentation - Trebinje 2011
Slide 9
Key Performance Indicators vs. LTE Field MeasurementKey Performance Indicators vs. LTE Field Measurement
x = probable, xx = most probable
Key Performance Key Performance Indicators vs. TestIndicators vs. Test
Sync Sync PowerPower
RS RS PowerPower
Occupied Occupied BW,BW,
ACLR, &ACLR, &SEMSEM
EVM EVM (pk)(pk) EVMEVM Freq Freq
ErrorErrorRx Rx
Noise Noise FloorFloor
OTA OTA EVM EVM
Call/Session BlockingCall/Session Blocking
Power shortagePower shortage xx xx xx
Resource Block shortageResource Block shortage xx xxxx xxxx
UL InterferenceUL Interference xx xxxx
Call/Session DropCall/Session Drop
Radio Link TimeoutRadio Link Timeout xx xx xx xx XX xx xx
UL InterferenceUL Interference xx xx
DL InterferenceDL Interference xx xx xx xx xx xx
CRONY company presentation - Trebinje 2011
Slide 10
LTE Field Measurement vs. BTS Field Replaceable UnitsLTE Field Measurement vs. BTS Field Replaceable Units
x = probable, xx = most probable
Test vs. BTS FieldReplaceable Units Freq Ref Signal
Generation MCPA Filters Antenna Antenna Down Tilt
Sync Power x xx x
RS Power x xx x
Occupied BW x xx xx
Adjacent Channel Leakage Ratio (ACLR) x x xx x
Spectral Emission Mask (SEM) x x xx x
Error Vector Magnitude Peak (EVM pk) x xx
Error Vector Magnitude (EVM) x x x x
Frequency Error xx
OTA EVM x x x x x
CRONY company presentation - Trebinje 2011
Slide 11
LTE Pass/Fail Mode LTE Pass/Fail Mode
LTE Pass/FailLTE Pass/Fail
Set up common test limits, or sets Set up common test limits, or sets of limits, for each instrumentof limits, for each instrument
User modify via MST to setUser modify via MST to set--up up systemsystem--wide maintenance wide maintenance operating practiceoperating practice
GuidelinesGuidelines
Direct ConnectDirect Connect
OTAOTA
Per VendorPer Vendor
ConsequencesConsequences
Inconsistent settings between Inconsistent settings between
base stations, leads to base stations, leads to
inconsistent network behaviorinconsistent network behaviorPass/Fail TestPass/Fail Test
CRONY company presentation - Trebinje 2011
Slide 12
LTE Occupied Bandwidth LTE Occupied Bandwidth
Occupied BandwidthOccupied Bandwidth
A measurement of the spectrum A measurement of the spectrum used by the carrier used by the carrier
The occupied bandwidth contains The occupied bandwidth contains 99% of the signal99% of the signal’’s RF power s RF power
Guideline Guideline –– Direct ConnectDirect Connect
Less than defined LTE bandwidthLess than defined LTE bandwidth
1.4, 3.0, 5.0, 10, 15, 20 MHz1.4, 3.0, 5.0, 10, 15, 20 MHz
ConsequencesConsequences
Leads to interference with Leads to interference with
neighboring carriersneighboring carriers
Dropped calls Dropped calls
Low capacityLow capacity
Common FaultsCommon Faults
Tx filter Tx filter
MCPA MCPA
Signal processingSignal processing
AntennasAntennas
RF QualityRF Quality
CRONY company presentation - Trebinje 2011
Slide 13
LTE Adjacent Channel Leakage Ratio (ACLR) LTE Adjacent Channel Leakage Ratio (ACLR)
ACLR ACLR (single(single--carrier displayed)carrier displayed)
Measures how much of the carrier Measures how much of the carrier gets into neighboring RF channels gets into neighboring RF channels
Checks the closest (adjacent) and Checks the closest (adjacent) and the next closest (alternate)the next closest (alternate)
Guideline Guideline –– Direct ConnectDirect Connect
--45 dBc adjacent channels45 dBc adjacent channels
--45 dBc alternate channels 45 dBc alternate channels
ConsequencesConsequences
InterferenceInterference
Low capacity Low capacity
Blocked callsBlocked calls
Common FaultsCommon Faults
Tx filter Tx filter
MCPA MCPA
Channel cards Channel cards
Cable connectors Cable connectors
RF QualityRF Quality
CRONY company presentation - Trebinje 2011
Slide 14
LTE Spectral Emission Mask (SEM) LTE Spectral Emission Mask (SEM)
Spectral Emission MaskSpectral Emission Mask
SEM checks closer to the signal SEM checks closer to the signal than ACLR doesthan ACLR does
It also is sensitive to absolute It also is sensitive to absolute power levelspower levels
May be requirement of regulatorsMay be requirement of regulators
Guideline Guideline –– Direct ConnectDirect Connect
Must be below mask Must be below mask
ConsequencesConsequences
Interference with neighboring Interference with neighboring
carriers carriers
Legal liabilityLegal liability
Low data rateLow data rate
Common FaultsCommon Faults
Check amplifier output filteringCheck amplifier output filtering
Look for intermodulation Look for intermodulation
distortiondistortion
Look for spectral reLook for spectral re--growthgrowth
RF QualityRF Quality
CRONY company presentation - Trebinje 2011
Slide 15
LTE Error Vector Magnitude (EVM)LTE Error Vector Magnitude (EVM)
EVMEVM
The ratio of errors, or distortions, The ratio of errors, or distortions, in the actual signal, compared to in the actual signal, compared to a perfect signala perfect signal
EVM measures the PBCH, if there EVM measures the PBCH, if there is no data traffic and the PDSCH if is no data traffic and the PDSCH if there is trafficthere is traffic
Guidelines Guidelines –– Direct ConnectDirect Connect
QPSK QPSK -- 17.5%17.5%
16 QAM 16 QAM –– 12.5%12.5%
64 QAM 64 QAM –– 8%8%
ConsequencesConsequences
dropped callsdropped calls
low data ratelow data rate
low sector capacitylow sector capacity
blocked callsblocked calls
Common FaultsCommon Faults
distortion in the channel cardsdistortion in the channel cards
Power amplifierPower amplifier
filterfilter
antenna systemantenna system
Modulation QualityModulation Quality
CRONY company presentation - Trebinje 2011
Slide 16
LTE Frequency Error LTE Frequency Error
Frequency ErrorFrequency Error
Checks to see that the carrier Checks to see that the carrier frequency is precisely correctfrequency is precisely correct
Regulatory requirement in many Regulatory requirement in many countriescountries
Guideline Guideline –– OTA with GPSOTA with GPS
±± 0.05 ppm wide area BS0.05 ppm wide area BS
±± 0.10 ppm local area BS0.10 ppm local area BS
±± 0.25 ppm home BS0.25 ppm home BS
ConsequencesConsequences
Calls will drop when mobiles Calls will drop when mobiles travel at higher speedtravel at higher speed
In some cases, cell phones cannot In some cases, cell phones cannot hand off into, or out of the cellhand off into, or out of the cell
Common FaultsCommon Faults
Reference frequencyReference frequency
Frequency distribution systemFrequency distribution system
GPS, if usedGPS, if used
BackhaulBackhaul
Modulation QualityModulation Quality
CRONY company presentation - Trebinje 2011
Slide 17
LTE Synchronization Signal ScannerLTE Synchronization Signal Scanner
Synchronization Signal PowerSynchronization Signal Power
Indicates which sectors are Indicates which sectors are present at the current locationpresent at the current location
Too many strong sectors creates Too many strong sectors creates frequency avoidance diminishing frequency avoidance diminishing capacitycapacity
Guideline Guideline –– Direct ConnectDirect Connect
3 or fewer codes3 or fewer codes
Within 10 dB of dominant codeWithin 10 dB of dominant code
Over 95% of the coverage areaOver 95% of the coverage area
ConsequencesConsequences
Low data rateLow data rate
Low capacityLow capacity
Common faultsCommon faults
Antenna down tilt Antenna down tilt
Damaged antennasDamaged antennas
Control channel power settingsControl channel power settings
Illegal repeatersIllegal repeaters
Downlink Coverage Quality
CRONY company presentation - Trebinje 2011
Slide 18
Downlink Coverage MappingDownlink Coverage Mapping
OTA Scanner has AutoOTA Scanner has Auto--SaveSave
Need GPS Receiver and AntennaNeed GPS Receiver and Antenna
Collects data Collects data ≈≈ every 5every 5--10 s10 s
Time depends on number of Sync Time depends on number of Sync
codes and whether Modulation is codes and whether Modulation is
turned onturned on
Master Software Tools can export Master Software Tools can export
data to a KML filedata to a KML file
Import into Google Maps/EarthImport into Google Maps/Earth
Mouse over point to see Scanner Mouse over point to see Scanner
resultsresults
Downlink Coverage Quality
CRONY company presentation - Trebinje 2011
Slide 19
LTE OTA Modulation Quality Testing LTE OTA Modulation Quality Testing
OTA Modulation Quality TestingOTA Modulation Quality Testing
Valid signal quality measurements Valid signal quality measurements can be made OTAcan be made OTA
Guidelines are established from a Guidelines are established from a known good base stationknown good base station
Must be taken in valid locationMust be taken in valid location
Valid OTA LocationValid OTA Location
OTA Scanner validates locationOTA Scanner validates locationDominance >10 dBDominance >10 dB
If Pass If Pass –– becomes sweet spotbecomes sweet spot
Note GPS locationNote GPS location
Becomes location for futureBecomes location for futureOTA Modulation Quality TestingOTA Modulation Quality Testing
Record and create Record and create OTA Pass/Fail limitsOTA Pass/Fail limits
OTA Modulation Quality
Valid EVM OTA measurementValid EVM OTA measurement
MIMO presents a challenge to MIMO presents a challenge to measure EVM OTAmeasure EVM OTA
Need to measure EVM of PBCH Need to measure EVM of PBCH which has Transmit Diversitywhich has Transmit Diversity
Measures both Tx1 & Tx2 Measures both Tx1 & Tx2
CRONY company presentation - Trebinje 2011
Slide 20
One quick test One quick test –– OTA Pass/Fail OTA Pass/Fail –– checks health of cell sitechecks health of cell site
Find valid OverFind valid Over--thethe--Air (OTA) locationAir (OTA) location
If not, direct connectIf not, direct connect
Run oneRun one--step Pass/Fail Teststep Pass/Fail Test
Checks Feed Line Quality, if OTAChecks Feed Line Quality, if OTA
Checks RF QualityChecks RF Quality
Checks Modulation QualityChecks Modulation Quality
Test data throughputTest data throughput
Use PC data cardUse PC data card
If everything passesIf everything passes
DONEDONE
If not troubleshootIf not troubleshoot
Feed lines and antenna systemFeed lines and antenna system
Base station field replaceable unitsBase station field replaceable units
Downlink Coverage issues Downlink Coverage issues
Interference problemsInterference problems
Backhaul bitBackhaul bit--errorerror--ratesrates
FoundValidOTA
spot?
Run OTA orDirect ConnectPass/Fail Test
Start
Start Direct ConnectTransmitter
TestN
Done
Run PC-basedThroughput Test
Pass?
TroubleshootFeed Lines
Base StationCoverage
InterferenceN
GoodThrough-
put?
TroubleshootBackhaul
N
Y
Y
Y
CRONY company presentation - Trebinje 2011
Slide 21CRONY company presentation - Trebinje 2011