1-12 two stage ota test method cmcc semina_agilent

8/13/2019 1-12 Two Stage OTA Test Method CMCC Semina_agilent

1/25

MIMO OTA ResearchUpdate

Ya Jing

Zhu Wen

Xu Zhao

Hongwei KongSteve Duffy

Moray Rumney

Agilent Technologies


2/25

Agenda

MIMO OTA BackgroundMIMO OTA Test Methods

MIMO OTA Test Application Scenarios

Two-stage Method and Multiple Probe Antenna MethodEffectiveness Validation

Using Two-Stage Method to Identify Antenna Performance Issue

Using Two-Stage Method to Test LTE Device OTA Performance

Summary


3/25

Background

Over-the-air (OTA) test is a mandatory test for conformance toevaluate the handset radiation performance

LTE MIMO OTA test is to be a mandatory test for LTE handsetdevices driven by operators addressing MIMO OTA challenges

MIMO OTA test method MIMO OTA channel model MIMO OTA measurement metrics MIMO OTA performance criteria

A hot LTE Test & Measurement topic for lots of companies


4/25

Spatial and Antenna Characteristics of the MIMOChannel

Tx0Tx1

Rx1Rx0

MS/UEBS

Tx0 GainPattern

Tx1 GainPattern Rx1 Gain

Pattern

Rx0 GainPattern

AoD SpatialDistribution

AoA SpatialDistribution


5/25

MIMO Channel Models and OTA Test Methods

UniformMultipath

Channel

Correlation-Based

Model

Geometry-BasedModel

(Sum of Sinusoids)

Geometry-BasedModel

(Quantized PAS)

Channel Approximations

Two-Stage OTA Method Multiple Probe

OTA Method

Reverberation

ChamberOTA Method


6/25

MIMO OTA MethodsMultiple Test Probe OTA Method

Agilent PXTE6621A

AgilentPXBN5106Achannelemulator RF up-

converters

RF connections

Digitalconnections

RF down-converters

Group probe antennas to emulate quantized PAS Does not require direct connection to DUT receivers Requires extensive system calibration Requires a high channel count


7/25

MIMO OTA MethodsReverberation Chamber OTA Test Method

Rapid OTA testing, cost effective, excellent for self-desensitization Statistically quasi-uniform fading channel characteristics

E6621A


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Throughput Test

E6621A PXT

E6621A PXT

MIMO OTA MethodsTwo-stage MIMO OTA Method

)(

RxG

Page 8

Stage 1 Antenna pattern

measurement

Stage 2Throughput

measurement

)( Tx PAS )( TxG )( Rx PAS

Or modeledpattern

Measuredpattern

Fast and very cost effective

Uses standard SISO anechoic chamber Can models any 2D or 3D channel usingcorrelation or geometry methods

Requires UE test mode for non-intrusiveantenna pattern measurement

MeasuredBS Emulator


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MIMO OTA Test Application Scenarios

The primary motivation for MIMO OTA test is fordevice conformanceBut other test scenarios exist that require OTA testsolutions MIMO antenna performance evaluation solutions for

performance optimization Solutions to locate the MIMO device radiation performance

issues Solutions to do pre-conformance test before formal

certification Solutions to rank device OTA performance

Different test application scenarios will have differentsensitivity to some aspects of the high level criteria onMIMO OTA test method

Problemcomplexity

Test speed# test runs


10/25

Antenna Design Issue AnalysisMIMO Antenna Gain

ANT #2 and ANT #1 performancedifference is partly related to thedifferent MIMO antenna gain

ANT#2 for most of the orientations hashigher antenna gain than ANT#1

ANT#1 has much bigger gain variationsthan ANT#2 during the rotation whichindicate poorer symmetry of the antenna

Average gain difference could be 1-2dBor more depending on different channelmodel

-92 -90 -88 -86 -84 -82 -80 -78 -76 -740

1

2

3

4

5

6

7

Power (dBm)

T h r o u

g h p u

t ( M b / s )

DUT1 UMiDUT2 UMiDUT1 SC-UMiDUT2 SC-UMiDUT1 UMaDUT2 UMaDUT1 SC-UMaDUT2 SC-UMa

-200 -150 -100 -50 0 50 100 150 200-13.5

-13

-12.5

-12

-11.5

-11

-10.5

-10

-9.5

-9

-8.5

Orientation (degree)

M I M O a n

t e n n a g a

i n ( d B )

UMaSC-UMaUMiSC-UMi

-200 -150 -100 -50 0 50 100 150 200-15

-14.5

-14

-13.5

-13

-12.5

-12

-11.5

-11

Orientation

M I M O A n t e n n a

G a i n

( d B )

UMaSC-UMaUMiSC-Umi

Significant performance difference for twotest antennas

ANT #1

ANT #2


11/25

Antenna Design Issue AnalysisPower Imbalance

The OTA throughput difference is partly related tothe different power imbalance of the twoantennas

ANT#2 has less severe power imbalance than #1 ANT#1 has significant power imbalance for one side

which indicate a poor symmetry of antenna as well

Depending on the channel model, the averagepower imbalance difference could be 1-2dB or more

-92 -90 -88 -86 -84 -82 -80 -78 -76 -740

1

2

3

4

5

6

7

Power (dBm)

T h r o u

g h p u

t ( M b / s )


-200 -150 -100 -50 0 50 100 150 2000

2

4

6

8

10

12

14

16

18


M I M O A n t e n n a

G a i n

( d B )

UMaSC-UMaUMiSC-UMi

-200 -150 -100 -50 0 50 100 150 2004

6

8

10

12

14

16

18

20

22

24


P o w e r

I m b a l a n c e

( d B )

UMaSC-UMaUMiSC-UMi


ANT #2

ANT #1


12/25

Antenna Design Issue AnalysisCorrelation

The OTA throughput difference is partlyrelated to the different correlation of thetwo antennas

ANT#2 has less severe correlation than ANT #1

-200 -150 -100 -50 0 50 100 150 2000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8


C o r r e

l a t i o n

UMaSC-UMaUMiSC-UMi

-200 -150 -100 -50 0 50 100 150 2000.5

0.55

0.6

0.65

0.7

0.75

0.8

0.85

0.9

UMaSC-UMaUMi

SC-UMi

-92 -90 -88 -86 -84 -82 -80 -78 -76 -740

1

2

3

4

5

6

7

Power (dBm)

T h r o u

g h p u

t ( M b / s )



ANT #2

ANT #1


13/25

Comparison of Two-stage and Single Cluster:Channel Power Correlation Coefficient and Capacity

0 50 100 150 200 250 300-0.5

0

0.5

1

1.5

2

2.5

3

3.5

4

AoA in degree

C h a n n e

l P o w e r

( d B )

4 subpath Ch1 power4 subpath Ch2 power20 subpath Ch1 power20 subpath Ch2 powerMeasured Ch1 powerMeasured Ch2 power

0 50 100 150 200 250 3000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

AoA in degree

A b s o l u t

i o n o f c o r r e

l a t i o n c o e f

f i c i e n t

4 subPath20 subpathMeasured correlation

PXB(Baseband

siginal generatorand channel

emulator)

ESG #1

ESG #2

ESG #3

ESG #4

Anechoic Chamber

Ant#1

Ant#2

Ant#3

Ant#4

EUT

Laptop

Amplifier #1

Amplifier #2

Amplifier #3

Amplifier #4

VSA 89640

TurningTable

Ant 2 Ant 3

Ant 4 Ant 1

AoA

0 50 100 150 200 250 3003

3.5

4

4.5

5

5.5

6

AoA in degree

C a p a c

i t y ( b i t / s /

H z )

4 subPath20 subpathMeasured

Channel Power Correlation Channel Capacity

Channel measurement with

multiple probe setupSetup inside chamber

Single path over four probes3GPP R4-103761


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Three Devices used to Compare HSDPA RXDiversity Performance Measurement Methods

Page 14

0.2

0.4

0.6

0.8

30

210

60

240

90

270

120

300

150

330

180 0

E6400 pattern

MainAUX

0.2

0.4

0.6

30

210

60

240

90

270

120

300

150

330

180 0

HW K4505 Pattern

MainAUX

0.5

1

1.5

2

30

210

60

240

90

270

120

300

150

330

180 0

Dipole Pattern (0.5 Lamda seperation)

Dipole 1Dipole 2

ANT #2 ANT #1 ANT #3Dipole (0.5 interval)


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-90 -88 -86 -84 -82 -80 -78 -76 -74 -72

10

20

30

40

50

60

70

80

Throughput, AS=35deg, VS=3km/ h

Equivalent Receiving Power (dBm)

T h r o u g h p u

t ( % )

E6400: Multiple ProbeE6400: Two StageK4505: Multiple ProbeK4505: Two Stage

E6400 with multiple probeantenna setup

E6400 with two-stage method setup

3GPP R4-103760

Scenario E6400:Standarddeviation (percent)

K4505:Standard deviation(percent)

AS=35 degree,VS=3km/h

0.483517051 3.06473018


0.62545 2.805225


1.884411 3.361457


0.969416 2.505081


1.130037 2.820557

Comparison of OTA Test Methods: Throughput


16/25

-100 -95 -90 -85 -80 -75 -70 -65 -60

10

20

30

40

50

60

70

80

90

Throughput, AS=35deg, VS=3km/h

Equivalent Receiving Power (dBm)

T h r o u g h p u t

( % )

ANT#1: Multiple Cluster UmiANT#1: Single Cluster UmiANT#1: Uniform EPAANT#1, Multiple Cluster UmaANT#2: Multiple Cluster UmiANT#2: Single Cluster UmiANT#2: Uniform EPAANT#2, Multiple Cluster UmaANT#3: Multiple Cluster UmiANT#3: Single Cluster UmiANT#3: Uniform EPA

Measurement Results for Receiver Diversity ModeChannel SensitivityUma limitsperformance to80%

Choice of channelmodel is more

important for non-ideal antennas(ANT #1, 2)

Page 16

For Rx diversity,

SC-UMi and UMihas the similarperformance

3GPP R4-104064


17/25

Two-stage Method Result Comparison withMultiple Probe Antenna based MethodTwo-stage test results indicate that the SC-UMi performance and UMi

performance should be similar for different device antennas Agilent performed SC-UMi multiple probe antenna test and its result are similarto the Umi multiple probe antenna test results by other companies.

This indicates that two-stage method can provide reasonable predictions on themultiple probe antenna test results

-100 -95 -90 -85 -80 -75 -70 -65 -600

500

1000

1500

2000

2500

3000

3500

4000

4500

5000HSet6 Max T-put

Channel Power (dBm)

T - p u t

( K b p s )

RR HSDPA Rx Div Results - HSet6 Umi

CS-15 -NokiaCS-15 -satimoCS-15 -AgilentCS-15 -Wiesbaden UniversityCS-15 -NTT DCMCS-15 -EMITE

3GPP R4-104768

CS-15 results for HSet6 under SCME Urban microcell (Umi)channel

-100 -95 -90 -85 -80 -75 -70 -650

500

1000

1500

2000

2500

3000

3500

4000

4500

5000HSet6 Max T-put

Channel Power (dBm)

T - p u t

( K b p s )

RR HSDPA Rx Div Results - HSet6 Umi

K4505 -Agilent AnechoicK4505 -Agilent 2-StageK4505 -Wiesbaden UniversityK4505 -EMITE

K4505 results for HSet6 under SCME Urban microcell (Umi) channel


18/25

Using Two-Stage Method To Test the LTE MIMODevice Performance: Antenna Measurement

Active antenna measurement

Pool1 DUT3 main antennapattern on polarization V

Pool1 DUT3 main antennapattern on polarization H

050

100150

0

100

200

300

-40

-30

-20

-10

0

Elevation (degree)Azimuth (degree)

A n t e n n a g a

i n ( d B )

050

100150

0

100

200

300

-40

-30

-20

-10

0

Elevation (degree)Azimuth (degree)

A n t e n n a g a

i n ( d B )


19/25

Active LTE MIMO Antenna Measurement Validation( 0.1 dB & 1 degree stability & good linearitywith power down to -60dBm)

MXG #0OutputPower(dBm)

MXG #1OutputPower(dBm)

MeasuredRSSI_RX0

(dBm)

MeasuredRSSI_RX1

(dBm)

RSSI_RX0Power Step

Error(dB)

RSSI_RX1Power Step

Error(dB)

-30 -30 -31.433 -30.1804 0 0

-40 -40 -41.2886 -40.0433 0.1444 0.137

-50 -50 -51.6027 -50.5056 -0.1698 -0.3252

-60 -60 -61.5879 -60.2891 -0.155 -0.1087

-70 -70 -71.6828 -71.5867 -0.2498 -1.4064

-80 -80 -81.6261 -81.6424 -0.1931 -1.4621

-90 -90 -90.5122 -90.973 0.9207 -0.7927

Page 19

Pattern Measurement Function Validation Platform

Table 1 Pattern Power Measurement Validation Results

Measured Power Distribution at Different Levels

Pattern Phase Measurement Validation Results

-1.5 -1 -0.5 0 0.5 1 1.50

0.2

0.4

0.6

0.8

1

1.2

1.4

Measured Phase - Measured Mean Phase (degree)

M e a s u r e

d P h a s e

O f f s e

t D i s t r i b u t

i o n

P r o b a b

i l i t y D e n c

i t y

Measured @ Output Power = -50dBm, Variance = 0.0868

-0.2 -0.1 0 0.1 0.2 0.3 0.4 0.50

2

4

6

8

10

12

Measured Power - Measured Mean Power (dB)

M e a s u r e

d P o w e r

O f f s e

t D

i s t r i b u t

i o n

P r o

b a b i l i t y

D e n c i

t y

-60dBm

-70dBm

-80dBm

-90dBm


20/25

RSSI Linearity Calibration

11/6/2011Oct. 2007Labs Beijing MIMO Project Review

-95 -90 -85 -80 -75 -70 -65 -60-95

-90

-85

-80

-75

-70

-65

-60

-55

Power Range (dB)

R S S I L e v e

l ( d B )

Pool1 DUT1, main

Pool1 DUT1, subPool1 DUT3, mainPool1 DUT3, subPool2 DUT1, mainPool2 DUT1, subPool3 DUT1, mainPool3 DUT1, sub

-90 -85 -80 -75 -70 -65 -60-90

-85

-80

-75

-70

-65

-60

-55

Power Range (dB)

R S S I L e v e

l ( d B )

Pool 2 DUT 2, main

Pool 2 DUT 2, subPool 3 DUT 2, mainPool 3 DUT 2, sub

Measured the RSSI linearity curves by controlling the receivedsignal power using cable-conducted methodRSSI measurement number shows good linearity on these DUTs

Antenna pattern was calibrated according to the measured RSSIlinearity curves


21/25

Noise and Interference Comparison between OTAand Cable-conduct Test

21

-100 -95 -90 -85 -80 -75 -70 -65 -60-102

-100

-98

-96

-94

-92

-90

-88

-86

-84

ML1 RSSI level (dB)

N o i s e p o w e r

( d B )

Measured the noise and interference property of the overall spheresurface when do DUT 3D pattern measurement in chamberMeasured the noise and interference property by controlling the receivedsignal power for cable-conducted caseFurther experiments and research are required on this topic

Pool3 DUT1 noise property for OTA and cable-conduct case


22/25

Using Two-stage Method To Test LTE OTA Performance

LTE MIMO OTA Throughput test system Throughput under single-cluster Umi channel model

Throughput under multi-cluster Umi channel model


23/25

DUTs Ranking and Some Findings

The performance under multi-cluster Umi and multi-cluster Uma is similarwhen the eNB side is set to un-correlated,

The performance curves under single-cluster channel model show widerspread than that under multi-cluster channel model, which demonstratesnarrow AS channel model makes the performance test more sensitive.

Pool1 DUT3 and Pool4 DUT1s ranking sequences are changed whenswitching from single-cluster to multi-cluster model, which demonstratesthese DUTs are sensitive to channel power angular spread

11/6/2011Oct. 2007Labs Beijing MIMO Project Review

Used Channel Model Ranking

High Medium Low

SC Umi Pool1 DUT1 Pool2 DUT1, Pool2 DUT2,

Pool3 DUT1, Pool1 DUT3,

Pool3 DUT2, Pool4 DUT 1

MC Umi Pool1 DUT1, Poo1 DUT3 Pool2 DUT1, Pool2 DUT2,

Pool3 DUT1

Pool4 DUT1, Pool3 DUT2

MC Uma Pool1 DUT1, Poo1 DUT3 Pool2 DUT1, Pool2 DUT2,

Pool3 DUT1

Pool4 DUT1, Pool3 DUT2


24/25

Round Robin Test Results from Other Companies

0

2

4

6

8

10

12

14

16

18

20

22

24

26

-111 -109 -107 -105 -103 -101 -99 -97 -95 -93 -91

Pool1Dev1-BlueTest

Pool1Dev1-Nokia

Pool1Dev1-Agilent

Pool1Dev3-BlueTest

Pool1Dev3-Agilent

Pool2Dev1-BlueTest

Pool2Dev1-Nokia

Pool2Dev1-NTTPool2Dev1-Satimo

Pool2Dev1-Agilent

Pool2Dev2-Bluetest

Pool2Dev2-Nokia

Pool2Dev2-Agilent

Other companies curves are referred by reading out the data in the pictures in theproposals submitted to 3GPP RAN4 meeting, including proposals: R4-111718,R4-114178, R4-MIMOOTAah-0002, R4-MIMOOTAah-0005 and R4-MIMOOTAah-0017.

Power/15KHz(dBm)

T h r o

u gh

p u t ( M b p

s )


25/25

Summary

The appropriate MIMO OTA test solution depends on the test purpose

MIMO OTA tests needs to have MIMO channel model and different MIMO OTAdiffers in the way to reproduce a specified MIMO channel model

Agilent is supporting several MIMO OTA test methods for different test applications

Agilent is proposing the two-stage MIMO OTA test method as a cost effectivemethod covering the stages of MIMO antenna optimization through to pre-conformance test and finally for conformance test if accepted by 3GPP RAN4 andCTIA

The two-stage method is shown to provide comparable test results to multiple probeantenna method through various measurement campaigns

Initial evaluation of non-intrusive (active) antenna pattern measurement shows good

measurement accuracy The two-stage LTE MIMO OTA test results correctly rank the device antenna

performance difference

The two-stage method can be effectively used to identify the antenna performanceissues and provide guidance on how to optimize the design

1-12 two stage ota test method cmcc semina_agilent

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