Base-Station-Antennas for optimizedMobile Communication Networks

Norbert Ephan, Roland GabrielKATHREIN-Werke KG, Postfach 100 444,

83004 Rosenheim, Germany

Kathrein-Werke KGRosenheimPO Box 10 04 44Phone:+ 49 (0)8031 184 - 0Fax: +49 (0)8031 184 991antennas.mobilcom@kathrein.dewww.kathrein.de

•• 1. Polarization 1. Polarization -- DiversityDiversity--AntennasAntennas

•• 2. Site2. Site--Sharing with Sharing with MultibandMultiband--AntennasAntennas

•• 3. Remote Electrical Tilt3. Remote Electrical Tilt

•• 4. Adaptive Antennas and Tower Top 4. Adaptive Antennas and Tower Top ElectronicsElectronics

Content

Evolution from Eurocell V-Pol. to A-Panel XX-Pol.

History: Base Station Antennas

1. Polarization Diversity Antennas

Diversity combining

Diversity with two antennas

-30

-25

-20

-15

-10

-5

0

5

10

1

Time

Sign

al L

evel

[dB

]

Rx 2Rx 1

Combined Signal

-30

-25

-20

-15

-10

-5

0

5

10

1

Time

Sign

al le

vel [

dB]

252321191715131197531

00.

20.

40.

60.

81

0

1

2

3

4

5

6

7

8

Div

ersi

ty G

ain

[dB

]

Signal Difference [dB]Cross-

Correlation

Maximal Ratio Combining

252321191715131197531

00.

20.

40.

60.

81

0

1

2

3

4

5

6

7

8

Div

ersi

ty G

ain

[dB

]

Signal Difference [dB]Cross-

Correlation

Maximal Ratio Combining

-- Level Level differencedifference-- CorrelationCorrelation

Diversity gain GSM Diversity gain GSM

Outage Probability (y<x)

1,E-04

1,E-03

1,E-02

1,E-01

1,E+00

-40 -30 -20 -10 0 10

10 log (x/Γ ) [dB]

Pr (

<x) single signal

max. ratio comb./uncorrelated signals

Div-gain 7 dB

Diversity

•Typical Diversity Gain for GSM - System (max. uncorrelated, equal level)

• Space Diversity Arrangement– uses two vertical polarized Rx antennas (Rxa and Rxb) with a horizontal

spacing of 12-15 λ

– Omni base station : 3 omni antennas with the Tx antenna on a higher level

3m3m

Diversity

Polarization-Diversity: Xpol construction

65° 90°

+45°-Polarization-45°-Polarization

Reflektor

Polarization Diversity Antennas: Radiators

„Vektor“-dipol -halfpower beamwidth 65°- 90° -low crosspol- level-broadband design(1710 - 2170 MHz)

Polarization Diversity Antenna Arrangements

PolarizationPolarization--DiversityDiversity--ArrangementArrangement

SpaceSpace--DiversityDiversity--ArrangementArrangement

X-Pol Array Antennas - Vector Dipole Characteristic

01530

45

60

75

90

105

120

135

150165

180195

210

225

240

255

270

285

300

315

330345

-30 -20 -10 dB

co-pol

cross-pol

Co-/Cross Pol. behavior015

30

45

60

75

90

105

120

135

150165

180195

210

225

240

255

270

285

300

315

330345

-30 -20 -10 dB

Frequency behavior

1710 - 2170 MHz> 25 dB (main direction)> 10dB (+/- 60° Sector)

Primary radiator designPrimary radiator design

Site-Sharing with Dual and Triple-Band Antennas

Dualband Antennas / XXpol System

TETRA 380 - 430 MHzGSM 450 MHzDVB-H 512-860 MHzAMPS 824 - 890 MHzGSM 900 880-960 MHzGSM 1800 1710 - 1880 MHzUMTS 1920 - 2170 MHzUMTS LTE 2500 - 2700 MHzWiMax 3.4 - 3.8 GHz

Major Mobile Major Mobile Communication FrequenciesCommunication Frequencies

Site Sharing and Multi-Band Antennas

XXPol-Dual-Bandmit Combiner

Single-Band-Antennenfür GSM900 und GSM1800

GSM1800(E-Netz)

GSM900(D-Netz)

Site Sharing and Multiband Antennas

Dualband antennas: XXpol construction

Triple-Band Antennas

TETRA 380 - 430 MHzGSM 450 MHzDVB-H 512-860 MHzAMPS 824 - 890 MHzGSM 900 880-960 MHzGSM 1800 1710 - 1880 MHzUMTS 1920 - 2170 MHzUMTS LTE 2500 - 2700 MHzWiMax 3.4 - 3.8 GHz

Major Mobile Major Mobile Communication FrequenciesCommunication Frequencies

Independent adjustable Downtilt

Triple- Band Antennas

6 Systems, independently adjustable- GSM 900 - GSM 1800 - UMTS

6 Systems, independently adjustable- GSM 900 - GSM 1800 - UMTS

Triple- Band Antennas

Scheme of Triple-Band-Antenna

Adjustable Electrical DT

C-Filter-Combiner

DPS-DifferentialPhase-Shifter

Combined radiators 806-960/1710-2170 MHz

Single radiators 1710 - 2170 MHz

1710-1880 MHz

1920-2170 MHz

2527293133353739414345

Isolation

0 1 2 3 4 5 6 7 8 9 100

2

4

6

Downtilt 900 MHz

Downtilt 1800 MHz

Isolation +/-45° Triple-Band-Antenna

frequencyfrequency

VSWRVSWR

Downtilt Downtilt GSM 1800GSM 1800

Sidelobe levelSidelobe level

isolationisolation

Crosspolar Crosspolar levellevel Halfpower Halfpower

beamwidthbeamwidth

TrackingTracking,,squintsquint

Downtilt Downtilt UMTSUMTS

Downtilt Downtilt GSM 900GSM 900

Complex design:Optimization Parameter of Triple-Band Antennas

Triple- Band Antennas

Remote Electrical Tilt

• maximum flexibility is achieved with adjustable electrical downtilt by combining the adjustability of the mechanical DT and the technical advantage of the electrical DT

Adjustable Electrical Downtilt

Ф

Ф

Ф

Ф

• Network Network Extension Extension •• Support of Support of traffic dependent cell breathing traffic dependent cell breathing and and regulation regulation of softof soft--

Handover areasHandover areas•• Hot Hot spots during special eventsspots during special events•• Dynamical traffic Dynamical traffic adaptive adaptive regulation regulation of of cell load cell load

Adjustable Electrical Downtilt

High trafficarea„Hot Spot“

„Cell Brathing“

– Electrical Tilt instead of Mechanical Tilt– Manual Adjustable: Team has to climb up the tower– RET offers flexible remote control (on site ore via O&M Network)

Adjustable Electrical Downtilt

RET

Adjustable Electrical DT

Triple-Band Antenna system 900 MHz +45°

Schemes of Triple-Band-Antenna

Passive Differential Phase Shifter

Schemes of Triple-Band-Antenna

Adjustable Electrical DT

DPS-DifferentialPhase-Shifter

Triple-Band Antenna system 2000 MHz +45°

C-Filter-Combiner

Influence of Downtilt-Optimization- a) RET and Pilot Power - b) RET, Pilot Power and Azimuth adjustment

Based on study results by Symena Software & Consulting GmbH Wien:www.symena.com „ The value of automated optimization“ ,publishing with allowance of Symena

UMTS / WCDMA-Network

Optimization of Service

80

82

84

86

88

90

92

94

96

98

1000 1100 1200 1300 1400 1500 1600 1700 1800 1900

Number of Subscribers

Serv

ice

Pro

pabi

lity

Without RETRET optimizedAzimuth optimized

Smart-BIAS-T

RET- Scenarios

OMC

BTS

Central Controlunit

RCU

Antenna

Feeder lines

TMA

Network-PlaningTool

Network-Extension

Changed Load Situation

(Rush Hour)Predefined Scenarios

ControlNetwork

„Dynamical“Modus

-Optimization Time-Reaction Time-Administration

Roll-Out of RET-System in Taipei/Taiwan

Adaptive Antennas and Tower Top Electronics

Adaptive Antennas

Transmit the power to the correct destination.

Antennas with beam-forming:

- "SMART" - Antennas- „Multi-Beam“-Antennas- Adaptive Antennas

Antennas with beamAntennas with beam--forming:forming:

-- "SMART" "SMART" -- AntennasAntennas-- „Multi„Multi--Beam“Beam“--AntennasAntennas-- Adaptive AntennasAdaptive Antennas

- Increased Capacity- Reduced interference level- Reduced Transmit-Power- Reduction of average EM

fieldsbut

-Expensive BTS-n x Feeder Cables-Higher Size- Reduced Site Sharing Capabilities

-- Increased CapacityIncreased Capacity-- Reduced interference levelReduced interference level-- Reduced TransmitReduced Transmit--PowerPower-- Reduction of average EMReduction of average EM

fieldsfieldsbutbut

--Expensive BTSExpensive BTS--n x Feeder Cablesn x Feeder Cables--Higher SizeHigher Size-- Reduced Site Sharing CapabilitiesReduced Site Sharing Capabilities

Adaptive Antennas - Control principles

Adaptive AntennaControl Options

Standard BTS

Control via:-Handover (Switched) -Soft Handover (Makro-

Diversity)

Special BTS for n Sensors

Beam-Forming Algorithm-Switched fixed beam-MRC principle

2X...4X array antennasoption: flat frequency phase-dependency for FDD

-2X...4X dual beam antennas-common 6-sector arrangements

-Backbone network takes over high traffic -or increased handovers required

Pilot carrier (BCCH) has to been distributed within the whole cell

BER MRC-Receiver, noncorrelated signals

1,E-07

1,E-06

1,E-05

1,E-04

1,E-03

1,E-02

1,E-01

1,E+00

31282624211916141297520-3-5-7-10-12-14-17-19

SNR [dB]

BER

Single Sensor2 sensors3 sensors

4 sensors

Diversity-gain

Adaptive Antennas

M=4 M=8

2

21

0, 4

1222

1

nt

t

rM

rMRCb

PP

rr

P

σµ

µµ

+=

−

−= ∑

−

=

noise

Tx-Power

For QPSK-Modulation, uncorrelated carriers:

MISO- Multiple Input- Single Output MRC

1 2 3 4 5 6 7 8

0

2

4

6

8

10

12

14

Gai

n [d

B]

Number of sensors

Array Gain

Array Gain (correlation=1)typical gainmax gain(correl=0)

Antenna/SensorTyp

Array gain(totalcorrelated)

Maxim umGain (noncorrelated)

Typicalgain

SinglePath

0 dB 0 dB 0 dB

Two Path 3 dB 8 dB 4..5 dBFour Path 6 dB 10.5 dB 6..10 dB8-Path 9 dB 13 dB 8..11 dB

- 2..4 sensors offer attractiveratio of gain/costs

Adaptive Antennas

Adaptive Antennas: 4x-solution

Improved Rx-signal, reduced Tx power

Digital data processingBeam steering algorithm

Dual-polarizedArray-Antenna 4x

(1x phase calibration)M=8

4 x Tx+4 x Rx Diversity

6-Sector-Arrangement: „Switched Beam“ Adaption

66--Sektor Sektor --Arrangements:Arrangements:--Increased CoverageIncreased Coverage--Equivalent TrafficEquivalent Traffic//CellCell--Reduced InterferenceReduced Interference

d6sect=1.41d3sect

Required additional gain for increasedradius(Okumarata-

Hata-Model)4,5..6 dB

tt rr

constor

subscribertor

area

sec3sec6 2secsec

=⇒

=≈

path loss

80

90

100

110

120

130

140

0,1 0,3 0,5 0,7 0,9 1,1 1,3 1,5 1,7 1,9

Distance [km]

Path

loss

[dB] h= 10 m

h=20mh=40mh=100m

Increased coverage

f=2GHz, gTx=18 dBi, Okumurata-Hata

Increased Coverage due to increased height of the Tx Antenna

„Ultra High sites“

∆h

6-Sector Ultra High sites

Dual-Beam-Antenna ( 2 Columns)

Adaptive Antenna: Dual Beam (2X)

3dB-Hybrid

Frequenz HPBW Azimuth

Frequenz HPBW Azimuth

Beam 1 Beam 2

Adaptive Antenna: Dual Beam (4X)

4x2 Butler-Matrix

Dual-Beam-Antenna ( 4 Columns)

Smart Antenna ( 2 Columns, 65° HPBW)

Horizontal Scan-Width0 degree5 degree

10 degree15 degree20 degree

Phase Shift (Columns)

0 degree30 degree60 degree90 degree

120 degree

Adaptive Antennas: Tracking 2X

MIMO-System:Combination of Pattern and Polarization-Diversity

Adaptive Antennas: MIMO-Systems

Tower Top electronics

TMA

Noise Figure

MCPA

BTSBTS

Multi-RRH

CPRICPRI--InterfaceInterface

PTx= 50 W

dissipation1= 25 W

dissipation2= 5 W

transmission= 20 W

Pin= 500 W

η= 1

0%

Tx-Linearizationcontrol

Rx2Tx Rx1

Re IMUp-Conv

Re ImDown-Conv

Re ImDown-Conv.

Rx2-Control ofAmplitude/Phase

PowerSupply

PowerRET

DigitalPredist.CPRI

CPRI CPRI

Adaptive AntennaArray with Multi-RRH4 x Tx, 8 x Rx

RET control

4x Antenna Array

Tower- Top Electronics: Multi-RRH