LTE Signal Quality Analysis - Crony LTE.pdf · Anritsu LTE Test Instrument Portfolio Signaling...

CRONY company presentation - Trebinje 2011

LTE Signal Quality AnalysisLTE Signal Quality Analysis

BTS MasterBTS Master™™, Cell Master, Cell Master™™, Spectrum Master, Spectrum Master™™

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)


Introducing the Next generation Anritsu Master familyIntroducing the Next generation Anritsu Master family

MT8221B

MT8222B

MT8212E

MT8213E

MS2721B

MS2722C

MS2723C

MS2724C

MS2725C

MS2726C


MS2712EMS2712E

MS2713EMS2713E

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


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


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


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


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


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


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


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


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


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


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)


--45 dBc adjacent channels45 dBc adjacent channels

--45 dBc alternate channels 45 dBc alternate channels


InterferenceInterference

Low capacity Low capacity

Blocked callsBlocked calls


Tx filter Tx filter

MCPA MCPA

Channel cards Channel cards

Cable connectors Cable connectors



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


Must be below mask Must be below mask


Interference with neighboring Interference with neighboring

carriers carriers

Legal liabilityLegal liability

Low data rateLow data rate


Check amplifier output filteringCheck amplifier output filtering

Look for intermodulation Look for intermodulation

distortiondistortion

Look for spectral reLook for spectral re--growthgrowth



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%


dropped callsdropped calls

low data ratelow data rate

low sector capacitylow sector capacity

blocked callsblocked calls


distortion in the channel cardsdistortion in the channel cards

Power amplifierPower amplifier

filterfilter

antenna systemantenna system

Modulation QualityModulation Quality


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


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


Reference frequencyReference frequency

Frequency distribution systemFrequency distribution system

GPS, if usedGPS, if used

BackhaulBackhaul

Modulation QualityModulation Quality


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


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


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


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


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


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


LTE Signal Quality Analysis - Crony LTE.pdf · Anritsu LTE Test Instrument Portfolio Signaling...

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Transcript of LTE Signal Quality Analysis - Crony LTE.pdf · Anritsu LTE Test Instrument Portfolio Signaling...