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Frequenz-agile, performante Echtzeit-Radiodatenverbindung

zwischen Flugzeug und Bodenstation!

Motivation 2

Real time transmission of airborne sensor data

Geo-referenced information

Wide coverage area

Adaptive mission processing

Cost effective solution

Suitable for small planes

LOS Ground Terminal

ADSB-Decoder

M-PSKModem

ACU

AZ, ELPedestal control

link

BidirectionalLOS data link

ADS-B

AircraftGPS Position

ADS-BTransponder

Onboard GPS

Sensor Platform

LOS Airborne Terminal

LAN

LAN

Ground Operator

Operator

GroundImage

Processing & Visualization

ImageProcessing

Architecture 3

Requirements 4

Optical and thermal images with a ground resolution of 10cm, @500m

compressed by a factor 10 to 30 results in up to 8 Mbit/s; 2 Images per second

Return link for protocol ACK, Monitoring and control of the on-board equipment and communication to the on board operator , < 500KBit/s

Un-compressed vs. Compressed Ortho Image 5

Requirements High frequency agility from 1,9 to 6 GHz because of different national regulations and license costs Range at least 30km with line of sight High spectral efficiency Small antenna and low weight for the airborne unit Bidirectional IP Interface

6

Frequencies High frequency agility from 1,9 to 6 GHz because of different national regulations and license costs 1900-1920 MHz and 2010- 2015MHz (CEPT) Other candidates: 2070-2110 MHz and 4400-4516 MHz 5080MHz 5,8 GHz Japan

7

TDD Front End

Antenna

Solid State RF Switch

SW

15V In

RX

TX

ANT

HPA15V -> 5V

15V -> 12V

0

50 Ohm

1

TX/RX Switch

High PowerSolid State RF Switch

1

0

LNA2 to 12 GHz

+12V+5V +5V

+5V

+12V

To / from RFDaughterboard

HighpassFc = 2GHz

8

FDD: - two frequencies are necessary! + simple front end TDD: + single frequency ! + Up / downlink BW variable – circulator (difficult because of wide band demand); Switch required. ( isolation!)

Access system 9

TDD Framing Structure 10

Link Budget Frequency 1,9 GHz to 6 GHz 3dB-Bandwidth 10,8 MHz Channel filter roll-off 0,35 Duplexing TDD Modulation scheme QPSK FEC Duo-binary Turbo code Coderate 4/5

Margin 5,7dB

Tx Power P1dB 31 dBm Maximum downlink data rate 8 Mbit/s

Maximum uplink data rate 0,5 Mbit/s

Maximum Distance 30 km

11

Hardware solution based on a SDR 12

Down conversion

+ FilterAmplifier

1.9 GHz to 6 GHz 0-32 dB fsample = 4* fsymbol

Up-Conversion

+ Filter

ETH1

Data Encapsulation

Turbo EncoderETH0 ETH1

ETH1

Transmit Chain in PC

Ö&M Timing EstimationCorrelation

NDA FESTRife Boorstin

dfTs

Turbo Decoder InterpolationDelay N

SymbolsPhase Tracker

Data Decapsu

lation

tauPosition Start of Frame

SymbolsETH0

Samples os4

Bit to Symbolmapping

I

Q

I

Q

QPSK bit to Symbol Mapper &

Zero Padding

fsample = 2* fsymbol

Packetizer

FPGA RX DSP Chain

ADC100 MHZ

14 bit

RRCOSro=0.35HBF1 HBF2

DAC100 MHZ

16 bit

RRCOSro=0.35HBF1HBF2

DigitalMixer

(w. NCO)

DigitalMixer

(w. NCO)

CIC1 – 128

CIC1 - 128

CBX Daughterboard

Amplifier

FPGA TX DSP Chain

USRP N210 + CBX Daughterboard

Receive Chain in PC

TDD Switch Control

TX

RX

SW

To / from RFFront End

13

Multi ground station network: Forward- link

Internet

Einsatz zentrale

SNR=4dB SNR=7dB

12

4

12

43

12

4

12

43

Router

12

43

Bodenstationen im Radioschatten

des Flugzeuges

14

Internet

Einsatz zentrale

SNR=4dB SNR=7dB

12

12

Router

12

Bodenstationen im Radioschatten

des Flugzeuges15

Multi ground station network: Return- link

Tracking System Mono-pulse is good but expensive and need first access information (telemetry channel) Step track is cheaper then Mono-pulse, less performance but need telemetry channel for first access Operation with telemetry channel only (broadcast) Using ADS-B information (1090MHz)

16

17

Field trial at Red Cross Exercise Allensteig 18

19

Summary Real time response for disaster management Integrated and tested a LOS link from a DA42 Data-rates verified ASDS-B tracking works well

20

JOANNEUM RESEARCH Forschungsgesellschaft mbH

Institut für Informations- und Kommunikationstechnologien

www.joanneum.at/digital

Michael Schmidt Michael.schmidt@joanneum.at +43 316 876-1311

Vielen Dank für Ihr Interesse!