technology and performance analysis for sotm · positioning, acquisition, and tracking (pat)...

© Fraunhofer IIS 1 15.10.2013 © Fraunhofer

SATCOM ON THE MOVE TESTING TECHNOLOGY AND PERFORMANCE ANALYSIS FOR SOTM SYSTEMS

Markus Landmann, Wolfgang Felber, Florian Raschke, Gregor Siegert, Mostafa Alazab, Giovanni Del Galdo

Fraunhofer Institute for Integrated Circuits IIS

© Fraunhofer © Fraunhofer IIS 2 15.10.2013

SATCOM ON THE MOVE TESTING Overview

SOTM test approach @FORTE

Demonstration of capabilities based on some results

SOTM-Testing for German armed forces


Test of

Antenna pattern

Positioning, Acquisition, and Tracking (PAT) performance

Residual off-axis emissions (interference to adjacent satellites)

Forward/Return link performance

End-to-end link performance (e.g. mobile to mobile)

including

Fading of the LMS channel including satellite signal impairments

Mechanical movement of the terminal platform

Interference from satellites in adjacent positions

for

Ku-Band (12/14 GHz) or Ka-Band (20/30 GHz)

Dual-linear or dual-circular polarization

FORTE Overview »Satcom« research platform


SOTM test approach @FORTE Facility Structure


SOTM test approach @FORTE Channel emulator


Realistic emulation of uplink and downlink channel:

Delay between satellite and earth station

Independent fading for up- and downlink

Replay of measured profiles

Replay from channel models

From customer provided data

SOTM test approach @FORTE Channel emulator / Test modes

Satellite Channel emulator








Emulation of satellite impairments :

Non-linearities

Carrier to Noise ratio C/N0 adjustable










Emulation of satellite impairments :

Non-linearities

Carrier to Noise ratio C/N0 adjustable

Test modes:

Transparent satellite

Communication to a fixed ground/mobile terminal

With assumed onboard processing (channel between the other communication partner and satellite can be neglected)




SOTM test approach @FORTE Anechoic chamber


Transparent window towards tower

Transparent window towards operational satellite (45° W to 45° E)

Completely closed for other applications

SOTM test approach @FORTE Anechoic chamber – Modes of operation


User terminal dynamics emulation (3-axis rotation)

Replay of measured or synthetic motion profiles

Data base for user terminal dynamics is currently under construction Land mobile and maritime (ESA AO 6669 – Mobile Tracking needs)

Parameters:

Payload dimensions:

Size Weight with reduced rate/acc.

90 cm diameter 30 kg 75 kg / 140 cm

Position: Rate / Acceleration: Roll Pitch Yaw

up to ±45° up to ±45° continuously

300 deg/s / 1000 deg/s2

300 deg/s / 1000 deg/s2

300 deg/s / 1000 deg/s2

Limitation: static accuracy bandwidth of pos. signal for amplitudes up to ±0.1°

< 0.0083° 5 Hz 20 Hz

SOTM test approach @FORTE Anechoic chamber – Motion emulator


User terminal dynamics emulation (3-axis rotation)

Replay of measured or synthetic motion profiles

Data base for user terminal dynamics is currently under construction Land mobile and maritime (ESA AO 6669 – Mobile Tracking needs)

SOTM test approach @FORTE Anechoic chamber – Motion emulator

kubandantenna.wmv


Recording of profiles using GENESYS ADMA inertial measurement unit

ADMA-G: Automotive Dynamic Motion Analyzer with differential GPS

SOTM test approach @FORTE Motion Profile Measurement System


Maritime @Sea-State 8 with dutch rescue boat

SOTM test approach @FORTE Motion Profiles Measurement


SOTM test approach @FORTE Motion Profiles Comparison


SOTM test approach @FORTE Antenna tower


Up- and Down converter:

For Ka and Ku band

80 MHz bandwidth

SOTM test approach @FORTE Antenna Tower – Main Payload



For Ka and Ku band

80 MHz bandwidth

Polarization:

Linear polarized

Circular polarized




For Ka and Ku band

80 MHz bandwidth

Polarization:

Linear polarized

Circular polarized

~20GHz, Zirkular, LHCP

~20GHz, Zirkular, RHCP

~30GHz, Linear, H

~11 GHz, Linear, H

~11 GHz, Linear, V

~13 GHz, Zirkular, LH

Ka-Band Ku-Band

Do

wn

lin

kU

p/D

ow

n

lin

k




For Ka and Ku band

80 MHz bandwidth

Polarization:

Linear polarized

Circular polarized

Clock:

Clock is synchronized over the entire facility




For Ka and Ku band

80 MHz bandwidth

Polarization:

Linear polarized

Circular polarized

Clock:

Clock is synchronized over the entire facility

Remote Control:

All devices controllable from laboratory building



Transparent satellite in Ku- and Ka band

Interfering satellite (planned, between 1°-3° separation)

Satellite elevation of 16°- 24°available

Power sensors in Ka/Ku band for De-pointing measurement

SOTM test approach @FORTE Antenna Tower – Satellite Emulation






SOTM test approach @FORTE Antenna Tower – Interfering Satellite






SOTM test approach @FORTE Antenna Tower – Satellite elevations






SOTM test approach @FORTE Antenna Tower – De-pointing Measurement System


objective: verification of the antenna tracking performance of SOTMs under realistic:

Motion

Channel conditions

Method:

1. measurement of reference data (pattern) with a sensor array of five sensors

2. correlation-based antenna de-pointing estimation on the Move

SOTM test approach @FORTE De-pointing estimation method


Excitation of with Tracking Mode Switched off

Estimation accuracy of FORTE in the order of 0.005 on average for a dish based system (Ka-Band, HPBW 1°) in a 1D-movement (azimuth or elevation)

-0.2 -0.1 0 0.1 0.20

0.01

0.02

0.03

0.04

0.05

Á [deg]

Con

¯d

ence

inte

rval

[deg

]

RMSE

Con¯dence interval bounds

0 5 10 15 20 -1.2

-0.8

-0.4

0

0.4

0.8

1.2

t [ s ]

[ d e ]

- E x c i t a t i n

Á - E s t i m a t e

Á - E s t . E r r o r

Excitation Estimation Est. Error

Am

pli

tud

e [

de

g]

time [s] De-pointing [deg]

Est

. D

evia

tio

n [

de

g] RMSE

Confidence Interval

SOTM test approach @FORTE De-pointing – Estimation Accuracy 1D


de-pointing estimation example

Ka-band High Gain antenna (1° antenna beam width)

circular movement of the antenna using 3-axis motion emulator (tracking mode switched off)

estimation accuracy better than

0.02° on average

-5 -4 -3 -2 -1 0 1 2 3 4 5-5

-4

-3

-2

-1

0

1

2

3

4

5

Á [deg]

µ[d

eg]

Reci

eve

d p

ow

er

[dB

m]

-60

-55

-50

-45

-40

-35

-30

-0.4 -0.2 0 0.2 0.4 0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

Á [deg]

µ[d

eg]

Excitation

Estimation

Rx

po

we

r [d

Bm

]

azimuth [deg]

azimuth de-pointing [deg]

ele

vati

on

[d

eg

]

ele

vati

on

de

-po

inti

ng

[d

eg

] movement estimation

SOTM test approach @FORTE De-pointing – Accuracy 2D


SATCOM ON THE MOVE TESTING Overview

SOTM test approach @FORTE

Demonstration of capabilities based on some results

Discussion


Demonstration of capabilities based on some results: Test Setup


Demonstration of capabilities based on some results: Test parameters

Antenna / Terminal Performance

max. EIRP (@P1dB) measurement

EIRP mask conformity

Pointing accuracy

Network performance (in presence of channel impairments):

Rx & Tx throughput for each link (e.g. SOTM <-> HUB) [MBit/s]

Latency [µs]

Packet Loss


Demonstration of capabilities based on some results: Antenna/Terminal performance – Max. EIRP

Max. EIRP Measurement procedure:

Detection of 1 dB compression point of BUC/SSPA

Power measurement of SOTM terminal @P1dB

Power measurement with reference (horn) antenna

Offset between both measurements determines EIRP of SOTM terminal


Demonstration of capabilities based on some results: Results – Network performance

Test results LMS channel effects (Fading only):


Demonstration of capabilities based on some results: Network performance - LMS channel effects (Fading only)


Demonstration of capabilities based on some results: Network performance - LMS channel effects (Doppler)

Test results LMS channel effects (Doppler, System 1):


Demonstration of capabilities based on some results Results – Network performance

Test results LMS channel effects (Doppler, System 2):


Demonstration of capabilities based on some results Results – Antenna/Terminal performance

EIRP mask conformity:

Detect maximum allowable EIRP@40kHz based on standardized mask (ETSI, Eutelsat, FCC, …) assuming no pointing inaccuracy

2D reference measurements



Depointing estimation for real world test track

Estimation for azimuth and elevation over time



Correlation between motion track and antenna depointing is hard to see (due to tracking algorithm)



Performance for two different antenna systems in comparison


Demonstration of capabilities based on some results Conclusion

Several benefits can be identified for SOTM tests at FORTE:

Complete system test under real-world conditions

No operational satellites have to be involved

Fully controllable and reproducible test environment

Individual effects can be tested separately or combined

Various test scenarios are available

Conclusion from precious SOTM terminal tests:

Identical test conditions do not guarantee identical system behavior

Separation of LMS channel effects and vehicle motion is beneficial to system performance evaluation

Various test scenarios and vehicles can be efficiently tested


SatCom On-The-Move at FORTE Contact

Dr.-Ing. Markus Landmann

mailto: [email protected] / [email protected]

phone: +49 3677 69-4297

fax: +49 3677 69-4282

Wireless Distribution Systems / Digital Broadcasting Research Group,

Fraunhofer Institute for Integrated Circuits IIS

Helmholtzplatz 2, 98693 Ilmenau, Germany

http://www.iis.fraunhofer.de

mailto:[email protected]

mailto:[email protected]

http://www.iis.fraunhofer.de/

technology and performance analysis for sotm · positioning, acquisition, and tracking (pat)...

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