COST Action IC 1407 Training School Prague, April 1 …...COST Action IC 1407 –Training School Prague, April 1-2, 2019 REVERBERATION CHAMBERS FOR TESTING WIRELESS DEVICES AND SYSTEMS

COST Action IC 1407 – Training SchoolPrague, April 1-2, 2019

REVERBERATION CHAMBERS FOR TESTING WIRELESS DEVICES AND SYSTEMS

V. Mariani Primiani

Università Politecnica delle Marche

Dept. Information Engineering

60131 Ancona - Italy

Signal propagation in realistic environment

201/04/2019COST IC 1407 Training School - Prague

"Reverberation chambers..."

1

( )T n n n

n

e e t u t

1

( )0

n

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if tu t

if t


"Reverberation chambers..." 3

Signal propagation in realistic environmentUrban environment Rural environment

Direct component (LOS)

Scattered component (NLOS)





LTE; Evolved Universal Terrestrial Radio Access(E-UTRA);User Equipment (UE) radio transmission and reception (3GPP TS 36.101 version 10.3.0 Release 10)

Definition of Reverberation Chamber

A properly operating RC is an electrically large cavity, where the electromagnetic field is statistically uniform, isotropic and randomly polarised within an acceptable and predictable uncertainty and confidence limit



Uniformity implies all spatial locations within RC (at sufficient distance from

metal surfaces) are equivalent

Isotropic implies that at given location in RC electromagnetic energy is

same in any direction

Random polarization implies that the phase relationships between polarized

components are equivalent

COST IC 1407 Training School - Prague "Reverberation chambers..."

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…….electrically large cavity…Frequency Domain

0 0 0

222

0 0 02

~ 1

m n p

mnp

V

mnpmnp

V

mnp

m n p

mnp

V

mnp

V

mnp

edVekk

dVeJ

jfdVf

dVfJ

jE

2

2 2 1 m

m

kk k j

Q

Field stirring actions

8

SOURCE STIRRING Generator amplitude or phase variation (Hill, …) Frequency variation (frequency stirring) (T. A. Loughry, …) Moving transmitting antenna to change mode coupling (Huang, Carlberg, Kildal, …) ….

MECHANICAL STIRRING, i.e. boundary condition variations

Rotating paddles (NIST group, …..)

Moving walls (Capsalis, …)

Vibrating walls (VIRC by Leferink, ..)

………….

For a review and history of all techniques see R. Serra, A. Marvin, F. Leferink, V. Mariani Primiani, F. Moglie, M. O. Hatfield, Y. Huang. L. Arnaut, A. Cozza. M. Klinger, "Reverberation chambers a la carte: An overview of the different mode-stirring techniques," in IEEE Electromagnetic Compatibility Magazine, vol. 6, no. 1, pp. 63-78, First Quarter 2017.

01/04/2019 COST IC 1407 Training School - Prague "Reverberation chambers..."

2

2 20 0 0

mnp

Vmnp

m n pmnp mnp

V

J e dV

j ek k e dV

MechanicalSource stir.

Example of mechanical stirring

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Ensemble average , mean value ( <X>N)Maximum value Max/Mean ratioStatistical distributions: PDF and CDF.



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…….electrically large cavity…Time Domain


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if t



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if tu t

if t

Statistical distributions in an ideal RC



CHI-2DOF (χ2 )

Distribution of the received power PR or of



2

iE

2

2CHI2-2DOF

ʃ

Statistical distribution of the total E-field



CHI-6DOF χ6

Example of received power statistics



CDF for the received power 1 GHz (Q=19600)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 1 2 3 4 5 6

Pr/<Pr>

Theor.Exp.

2

2 1 expCDF s s

s = mean normalised received power

Chamber dimensions 6 x4 x2.5 mf0 = 45 MHz

Stirring ratio 42 dB

We have to move toward a non-ideal RC to create a realistic propagation channel



Distribuzione di

Rayleighn

Rician distribution

Chamber Set-up for Rician Environment



Antenna positioning toward the DUTAntenna positioning away from the DUT

By varying the characteristics of the reverberation chamber and/or the antenna

configurations in the chamber, any desired Rician K-factor can be obtained.

Reverberation Chamber Ricean Environment

• We see that K is proportional to D. This suggests that if an antenna with awell defined antenna pattern is used, it can be rotated with respect to theDUT, thereby changing the K-factor.

• Secondly, we see that if r is large, K is small (approaching a Rayleighenvironment); if r is small, K is large. This suggests that if the separationdistance between the antenna and the DUT is varied, then the K-factorcan also be changed to some desired value.

• Next we see that by varying Q (the chamber quality factor), the K-factorcan be changed to some desired value. The Q of the chamber can easilybe varied by simply loading the chamber with lossy materials.



See Holloway et al, IEEE Trans on Antenna and Propag., 2006.

27

How can we generate a Rician environment ?


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Parameters of interest for the channel emulation

Impulse Responses and Power Delay Profiles

One characteristic of the PDP that has been shown to be particularly important

in wireless systems that use digital modulation is the rms delay spread of the PDP



Insertion of absorbing material to tune the PDP



PDP of an oil refinery

By NIST



τRMS = 20.64 ns

τRMS = 22.54 nsτRMS = 30.46 nsτRMS = 34.25 ns

Living room (St) Laboratory

Absorber positioning

32

+ +


"Reverberation chambers..."



The chamber coherence bandwidth

Average modal bandwidth

Coherence bandwidth

Subcarriers, Df = 15 kHz

Channel band

Bc

“Nokia Solutions and Networks” Flexi Multiradio 10 BTS

3 sectors RF modules; Maximum 80 W x antenna connector; band 20 (800 MHz) and band 3 (1.8 GHz);

6 x 4 x 2.5 m reverberation chamber

Over-The-Air tests in RC of a real Base Station


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Empty chamber Medium load High load

Reference signal received power (RSRP): is the average of the power of resource elements that carry cell-specific reference signals

Reference signal received quality (RSRQ): is based on the ratio of RSRP and RSSI (total wideband received power)

PDSCH net throughput: is the throughput measured at physical layer at the client in the data downlink channel, removing the re-transmissions of negatively acknowledged TBs.Signal to interference and noise ratio (SINR): is the ratio between the wanted part of the signal and the sum of interference and noise

Example of a transmission quality test


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Modulation and Coding Scheme (MCS) distribution


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Medium load1°/s 30°/s 80°/s

High load1°/s 30°/s 80°/s

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

high (70 Mbps)_em

pty_stirring_1 °/sec

high (70 Mbps)_em

pty_stirring_30°/sec

high (70 Mbps)_em

pty_stirring_80°/sec

high (70 Mbps)_m

edium_stirring_1 °/sec

high (70 Mbps)_m

edium_stirring_30°/sec

high (70 Mbps)_m

edium_stirring_80°/sec

high (70 Mbps)_high_stirring_1 °/sec

high (70 Mbps)_high_stirring_30°/sec

high (70 Mbps)_high_stirring_80°/sec

MCS code distribution

PDSCH_TRANS_USING_MCS28 (M8001C73)






0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

very lo

w (1

0 M

bp

s)_e

mp

ty_stirrin

g_1

°/sec

very lo

w (1

0 M

bp

s)_e

mp

ty_stirrin

g_3

0°/se

c

very lo

w (1

0 M

bp

s)_e

mp

ty_stirrin

g_8

0°/se

c

very lo

w (1

0 M

bp

s)_m

ed

ium

_stirrin

g_1

°/sec

very lo

w (1

0 M

bp

s)_m

ed

ium

_stirrin

g_3

0°/se

c

very lo

w (1

0 M

bp

s)_m

ed

ium

_stirrin

g_8

0°/se

c

very lo

w (1

0 M

bp

s)_h

igh_

stirring_

1 °/se

c

very lo

w (1

0 M

bp

s)_h

igh_

stirring_

30

°/sec

very lo

w (1

0 M

bp

s)_h

igh_

stirring_

80

°/sec

MCS code distribution








Empty chamber1°/s 30°/s 80°/s

MCS 22-28Modulation 64QAM for PDSCH

Ro

bu

stn

ess

Trans. B

lock Size

36696

31704

30576

28336

27376

25456

22920

Transport block size (for 50 PRBs)

TP >70Mbps

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Carrier aggregation


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Uplink in presence of interference and noise


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Maximum Ratio Combining (MRI) Interference Rejection Combining (IRC) Coordinated MultiPoint (CoMP)

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RS DTX RS DTX

DTX RS DTX RS

RS DTX RS DTX

DTX RS DTX RS

...........DTX DTX PBCH PBCH PBCH PBCH

DTX DTX PBCH PBCH PBCH PBCH

RS DTX DTX DTX RS DTX PBCH PBCH DTX



DTX RS SSS PSS DTX DTX PBCH PBCH RS

SSS PSS PBCH PBCH PBCH PBCH


RS DTX SSS PSS RS DTX PBCH PBCH DTX

...........SSS PSS PBCH PBCH PBCH PBCH


DTX RS SSS PSS DTX DTX PBCH PBCH RS



RS DTX DTX DTX RS DTX PBCH PBCH DTX



DTX RS DTX DTX DTX DTX PBCH PBCH RS

...........

RS DTX RS DTX

DTX RS DTX RS

RS DTX RS DTX

DTX RS DTX RS

TIME (2 slots = 1 TTI = 1 ms = 14 OFDMA symbols) - this is 1st TTI in 10 ms multiframe

fre

qu

en

cy (

1°

PR

B =

12

sub

carr

iers

= 1

80

KH

z)

fre

qu

en

cy (

50

° P

RB

= 1

2

sub

carr

iers

= 1

80

KH

z)ce

ntr

a 7

2 s

ub

carr

iers

= 6

PR

Bs

= 1

.08

MH

z

cen

tra

l6 P

RB

s

wh

ole

ba

nd

(5

0 P

RB

s)

resource elementsfor PHICH, PCFICH (these could be boosted via parameters) and PDCCH (control channel)

resource elements for RS (Reference Signals)

discontinuoustransmission

resource elements for broadcast channel (PBCH)

resource elementsfor primarysynchronization(PSS)

resource elementsfor secondarysynchronization(SSS)

resource elementsfor PDSCH (trafficchannel)

Uplink in presence of interference and noise

01/04/2019

MIMO 4x4 configuration


40

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

26.9 24.9 22.8 19.4 15.1 10.4 5.5 0.4 -4.8 -9.2

Mo

du

lati

on

uti

liza

tio

n %

SINR MIMO 4x4 [dB]

Modulation utilization %

Mod. CW1 256QAM Mod. CW1 64QAM Mod.CW1 16QAM Mod. CW1 Q-PSK

0%

20%

40%

60%

80%

100%

26.9 24.9 22.8 19.4 15.1 10.4 5.5 0.4 -4.8 -9.2

Ran

k u

tili

zati

on

[%]

SINR MIMO 4x4 [dB]

Rank utilization %

RANK 1 RANK 2 RANK 3 RANK 4

Duty

cycle

No

ise

ge

ne

rato

r

RC

QXDM

1800 MHz

LTE eNB transmitters

R&S

Attenuator array

Antennas transmitting useful

signal (S) 2 panels x-pol

Logperiodic

noise antenna

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High speed trains: effect of Doppler shift and fading on Throughput and Success rate


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High speed trains


42

Improving signal orthogonality preservation by the so-called PRACH of a restricted set of cyclic shifts in the random access procedure.

After the RC lab. testing, the benefit of using a larger separation between sequences was verified in the Northern Italy High Speed Rail Line between Bologna and Piacenza.

01/04/2019

5G Base Stations: a new challenge for the RC testing



Higher frequency range (e.g. 28 GHz) Higher channel bandwidth (200 MHz-

400 MHz) Beam forming Beam steering Reduced beam width (6 deg.) Very compact equipment: base band

electronics, MW electronics, and antennas highly integrated.

The whole eN inside the RC: power supply, ventilation, safety, …..

References• IEC 61000-4-21, “Electromagnetic compatibility (EMC) - Part 4-21: Testing and measurement techniques –

Reverberation chamber test methods”.

• David A. Hill, “Electromagnetic Fields in Cavities:Deterministic and Statistical Theories”, 2009, Wiley-IEEE Press

• Philippe Besnier, Bernard Démoulin, “Electromagnetic Reverberation Chambers”, Sep 2011, Wiley-ISTE.

• Stephen J. BoyesYi Huang, “Reverberation Chambers: Theory and Applications to EMC and Antenna

Measurements”, 2015, John Wiley & Sons, Ltd.

• R. Serra, A. Marvin, F. Leferink, V. Mariani Primiani, F. Moglie, M. O. Hatfield, Y. Huang. L. Arnaut, A. Cozza. M.

Klinger, "Reverberation chambers a la carte: An overview of the different mode-stirring techniques," in IEEE

Electromagnetic Compatibility Magazine, vol. 6, no. 1, pp. 63-78, First Quarter 2017.

• F. Leferink, “High Field Strength in a Large Volume: The Intrinsic Reverberation Chamber”, IEEE EMC 1998,

Denver, CO, USA

• C. Lötbäck Patané, A. Sk°arbratt, R. Rehammar, and C. Orlenius, “Basic and advanced MIMO OTA testing of

wireless devices using reverberation chamber,” in Proc. 8th Eur. Conf. Antennas Propag., The Hague, Netherlands,

Apr. 2014, pp. 3488–3492.

• X. Chen, “Measurement uncertainty of antenna efficiency in a reverberation chamber,” IEEE Trans. Electromagn.

Compat., vol. 55, no. 6, pp. 1331–1334, Dec. 2013.

• GPP, “Universal mobile telecommunications system (umts); lte; universal terrestrial radio access (utra) and evolved

utra (e-utra); user equipment (ue) over the air (ota) performance; conformance testing,” ETSI, Sophia Antipolis

Cedex, France, 3GPP Technical Specification TS37.544, V14.1.0, Apr. 2017.

•



References, cont.• C. M. J. Wang, K. A. Remley, A. T. Kirk, R. J. Pirkl, C. L. Holloway, D. F. Williams, and P. D. Hale,

“Parameter estimation and uncertainty evaluation in a low Rician K-factor reverberation-chamberenvironment,” IEEE Trans. Electromagn. Compat., vol. 56, no. 5, pp. 1002–1012, Oct. 2014.

• C. S. Lötbäck Patané, A. Sk°arbratt, and C. Orlenius, “Extending the reverberation chamber using achannel emulator for characterisation of over-the-air performance of multiple-input–multiple-outputwireless devices,” IET Science, Measurement Technology, vol. 9, no. 5, pp. 555– 562, 2015.

• A. Hussain and P.-S. Kildal, “Study of OTA throughput of 4G LTE wireless terminals for different systembandwidths and coherence bandwidths in rich isotropic multipath,” in Proc. 7th Eur. Conf. AntennasPropag., Gothenburg, Sweden, Apr. 2013, pp. 312–314.

• M. Barazzetta, D. Micheli, L. Bastianelli, R. Diamanti, M. Totta, P. Obino, R. Lattanzi, F. Moglie, and V.Mariani Primiani, “A comparison between different reception diversity schemes of a 4G-LTE basestation in reverberation chamber: a deployment in a live cellular network,” IEEE Trans. Electromagn.Compat., vol. 59, no. 6, pp. 2029–2037, Dec. 2017.

• D. Micheli, M. Barazzetta, C. Carlini, R. Diamanti, V. Mariani Primiani, and F. Moglie, “Testing of thecarrier aggregation mode for a live LTE base station in reverberation chamber,” IEEE Trans. Veh.Technol., 2016, available online. DOI: 10.1109/TVT.2016.2587662.

• Guidelines for evaluation of radio interface technologies for IMT– Advanced, InternationalTelecommunication Union - ITU Report M.2135-1, Dec. 2009.

• Propagation data and prediction methods for the planning of indoor radiocommunication systems andradio local area networks in the frequency range 900 MHz to 100 GHz, InternationalTelecommunication Union - ITU Recommendation P.1238-7, Feb. 2012.



• C. L. Holloway, H. A. Shah, R. J. Pirkl, K. A. Remley, D. A. Hill, and J. Ladbury, “Early time behavior in reverberation chambers and its effect

on the relationships between coherence bandwidth, chamber decay time, RMS delay spread, and the chamber buildup time,” IEEE Trans.

Electromagn. Compat., vol. 54, no. 4, pp. 714–725, Aug. 2012.

• X. Chen, P.-S. Kildal, C. Orlenius, and J. Carlsson, “Channel sounding of loaded reverberation chamber for over-the-air testing of wireless

devices: Coherence bandwidth versus average mode bandwidth and delay spread,” IEEE Antennas Wireless Propag. Lett., vol. 8, pp. 678–681,

2009.

• C. L. Holloway, D. A. Hill, J. M. Ladbury, P. F. Wilson, G. Koepke, and J. Coder, “On the use of reverberation chambers to simulate a Rician

radio environment for the testing of wireless devices,” IEEE Trans. Antennas Propag., vol. 54, no. 11, pp. 3167–3177, Nov. 2006.

• K. A. Remley, R. J. Pirkl, C.-M. Wang, D. Senić, A. C. Homer, M. V. North, M. G. Becker, R. D. Horansky, and C. L. Holloway, “Estimating

and correcting the device-under-test transfer function in loaded reverberation chambers for over-the-air tests,” IEEE Trans. Electromagn.

Compat., 2017, accepted for pubblication, DOI: 10.1109/TEMC.2017.2708985.

• E. Genender, C. L. Holloway, K. A. Remley, J. Ladbury, G. Koepke, and H. Garbe, “Use of reverberation chamber to simulate the power delay

profile of a wireless environment,” in Proc. IEEE Int. Symp. Electromagn. Compat., Hamburg, Germany, Sep. 2008, pp. 1–6.

• O. Delangre, P. De Doncker, M. Lienard, and P. Degauque, “Delay spread and coherence bandwidth in reverberation chamber,” Electronics

Letters, vol. 44, no. 5, pp. 328–329, 2008.

• L. Bastianelli, L. Giacometti, V. Mariani Primiani, and F. Moglie, “Effect of absorber number and positioning on the power delay profile of a

reverberation chamber,” in 2015 IEEE International Symposium on Electromagnetic Compatibility (EMC), Dresden, Germany, Aug. 2015,pp.

422–427.

• ——, “Verification of radiated multi-antenna reception performance of user equipment (UE) (release 12),” ETSI, Sophia Antipolis Cedex,

France, 3GPP Technical Specification TR37.977, V12.1.0, Mar. 2014.

• P.-S. Kildal, C. Orlenius, and J. Carlsson, “OTA testing in multipath of antennas and wireless devices with MIMO and OFDM,” Proc. IEEE, no.

7, pp. 2145–2157, Jul. 2012.



References, cont.

References, cont.• N. Janssen, K. A. Remley, C. L. Holloway, and W. F. Young, “Correlation coefficient and loading effects

for MIMO antennas in a reverberation chamber,” in Int. Symp. Electromagn. Compat. (EMC EUROPE),

Brugge, Belgium, Sep. 2013, pp. 514–519.

• P.-S. Kildal and K. Rosengren, “Correlation and capacity of MIMO systems and mutual coupling,

radiation efficiency and diversity gain of their antennas: Simulations and measurements in reverberation

chamber,” IEEE Commun. Mag., vol. 42, no. 12, pp. 102–112, Dec. 2004.

• D. Micheli, M. Barazzetta, F. Moglie and V. Mariani Primiani, "Power Boosting and Compensation During OTA Testing of a Real 4G LTE Base Station in Reverberation Chamber," in IEEE Transactions on Electromagnetic Compatibility, vol. 57, no. 4, pp. 623-634, Aug. 2015.

• A. J. Pomianek, K. Staniec, and Z. Joskiewicz, "Practical Remarks on Measurement and Simulation Methods to Emulate the Wireless Channel in the Reverberation Chamber," Progress In Electromagnetics Research, Vol. 105, 49-69, 2010.

Many, many others .. sorry for missing.



Dedicated sessions at Conferences• EMC Europe 2019, INTERNATIONAL SYMPOSIUM AND EXHIBITION ON

ELECTROMAGNETIC COMPATIBILITY, 2-6 SEPT. 2019, BARCELONA,

SPAIN.

• IEEE EMCS Symposium on ELECTROMAGNETIC COMPATIBILITY,

SIGNAL & POWER INTEGRITY, 22-26 July, 2019, New Orleans,

Louisiana).

Documents

COST Action IC 1407 Training School Prague, April 1 …...COST Action IC 1407 –Training School Prague, April 1-2, 2019 REVERBERATION CHAMBERS FOR TESTING WIRELESS DEVICES AND SYSTEMS