The Fully Networked Car Geneva, 4-5 March 2009 1 Asier Alonso Muñoz Intelligent Transport...
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The Fully Networked Car Geneva, 4-5 March 2009 1 Asier Alonso Muñoz Intelligent Transport Communication Networks Researcher TECNALIA-TELECOM
Transcript of The Fully Networked Car Geneva, 4-5 March 2009 1 Asier Alonso Muñoz Intelligent Transport...
The Fully Networked Car Geneva, 4-5 March 2009
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Asier Alonso MuñozIntelligent Transport Communication Networks Researcher
TECNALIA-TELECOM
The Fully Networked Car Geneva, 4-5 March 2009
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SDR Based Methodology for On-Board Communications
Systems Design
The Fully Networked Car Geneva, 4-5 March 2009
3The next “big thing” ?
EFFICIENCYEFFICIENCY
COMFORT & INFOTAINMENTCOMFORT & INFOTAINMENT
V2V
R2V
I2V
V2U
V2V
R2V
I2V
V2U
SAFETY
NAVIGATION & TRACKINGNAVIGATION & TRACKING
The Fully Networked Car Geneva, 4-5 March 2009
4Probably!, but some challenges still unsolved
1. Many radio standards forced to coexist on board, integrated in a single device !?
2. Time mismatch between cars and communication equipment lifecycles
3. Radio standards not fully harmonized worldwide
The Fully Networked Car Geneva, 4-5 March 2009
5Our motivation
To find an innovative design methodology for on-board (and infrastructure) devices which enables multiple radio integration
To define a reconfigurable system architecture which enables seamless evolution towards new communication standards
To design a new signal processing algorithm which, making use of new acquisition techniques, allows reducing the number of Hw components
The Fully Networked Car Geneva, 4-5 March 2009
6… and here it comes SDR !
o One device per One single device waveform integrating multiple
radioso Many Hw components Single programmable
device (FPGA, DSP)
Traditional SDR platform scheme
Amplifying +Filtering +Downconverting
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7What SDR provides…
1. Different waveforms in a single device• Multiple standards integrated• Costs dramatically reduced
— Manufacturing, logistical support and operating expenditures
2. Reconfigurability and upgradability• New standards, features or capabilities added
— Over-The-Air (OTA) reprogramming
• Lifecycle mismatch reduced customer satisfaction improved
3. Specific location-based Sw loads• Addressing regional/national requirements
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8SDR-based On-Board Hw Architecture
Acquisition Unit
Digitization parts (ADC/DAC)
RF Front-end
External Interfaces
US
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pu
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Configuration Unit
PR
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JTA
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Digitization parts (ADC/DAC)
RF Front-end-
US
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Eth
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PR
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JTA
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Digitization Parts (ADC/DAC)
RF Front End
US
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Signal Processing
ProcessorMemory Elements
RAM Unit
Ext. Memory Card
Processing Unit ClockMgmt Unit
Clo
ckD
istr
ibut
or
Osc
illat
or
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9Signal Processing
o Digitization in SDR systems is made:• In theory, just after the antenna• In practice, after the RF front end
—This adds limitations regarding flexibility
o A possible solution direct digitization
• Choice of an appropriate sampling frequency• Digital front-end design
BPF ADC
LNA
Receiver Front-End
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10Sampling Frequency Choice
o Bandpass sampling allows supressing analog downconversion from the RF front-end, but it requires:• Careful study of the appropriate sampling
frequency• Analysis of the generated spurious signals
o Two main benefits:• Bandwidth reduction for acquiring multiple
signals• More flexibility
The Fully Networked Car Geneva, 4-5 March 2009
11Sampling Frequency Choice (cont’d)
o Example: GNSS signals GPS (L1) & Galileo (E5a/b) Full Bw = 400 MHz
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12Sampling Frequency Choice (cont’d)
o Final frequency after aliasing is:
o Our goal was to match Galileo and GPS central frequencies so we obtain:
Fal = M*Fs ± Fo
-N*Fs+FGPS=M*Fs-FGal
The Fully Networked Car Geneva, 4-5 March 2009
13Sampling Frequency Choice (cont’d)
7 possible sampling frequencies :
Fs (MHz)
GPS L1 (MHz)
Galileo E5a
(MHz)
Galileo E5b
(MHz)
1383.3 191.75 207.25 176.25
691.6 191.75 207.25 176.25
461.1 191.75 207.25 176.25
307.4 38.06 53.56 22.56
251.5 66.00 81.50 50.50
153.7 38.056 53.56 22.56
110.7 25.76 41.26 10.26
0 10 20 30 40 50 60 70 80-100
-95
-90
-85
-80
-75
-70
-65
-60
-55
-50
f(MHz)
P(d
Bm
)
Final Bw = 60 MHz
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14Digital Front-End Design
o Each GNSS signal is processed independently
o Each band is processed with a standard downsampling scheme
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15Results
o Two ways of studying the behaviour of the system:
1. Preliminary Simulink/Modelsim analysis chosen sampling frequency = 153.7MHz
2. Laboratory tests measuring of dynamic range (main drawback of direct digitization)
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o Dynamic range tests: If signal power decreases undesired spurious signals
Dynamic range = 40 dB = ADC’s DR
Results (cont’d)
0 1 2 3 4 5 6 7 8
x 106
-130
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
f(Hz)
Leve
l(dB
m)
Received spectrum for a input CNR= -20 dB
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17Conclusions
o The three proposed objectives have been met:
1. Choosing a new paradigm of design for reconfigurable systems SDR
2. Designing an architecture for on-board devices Generic open platform
3. Finding new signal processing algorithms which can reduce the number of Hw elements Digital Front-End for Direct Digitization
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18Next Steps
o Designing a flexible analog front-end which allows working with different real signals
o Research on algorithms which allow dynamic reconfiguration of the system
The Fully Networked Car Geneva, 4-5 March 2009
19Thank you !
Asier Alonso MuñozIntelligent Transport Communication Networks Researcher
TECNALIA [email protected]
www.tecnalia.es/telecom www.robotiker.es
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Backup Slides
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o TECNALIA Telecom develops its activity in the following Research Fields:• Broadband Networks• Wireless Systems• Mobile Service Platforms
o TECNALIA Telecom provides:• Joint collaboration in Pre-competitive, Public-
funded projects• Contract based Research and Development
Projects• IPR and Research assets (Products &
Technology)• New exploitation routes for innovation: spin-
ins, spin-offs, joint-ventures, etc.
TECNALIA TelecomBusiness Unit of TECNALIA for the Telecommunications
Sector
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o Within the Wireless Systems Research Area, the Intelligent Transport Communication Networks Group specializes in communication technologies for transport/vehicular environments, focusing its activity in applied research for V2X in:• On-board system optimisation (OBUs, in-vehicle comms – CAN, BT,
UWB, NFC, RFID)• VANET networks and devices (WAVE, 802.11p, IR, ZigBee)• Cooperative systems for road transport• Broadcasting (DAB, DVB-H, SDR)• Network architectures (3G, WiMAX, Ad-Hoc, routing)• GNSS technologies (GPS, GALILEO, EGNOS) and indoor guidance
o Facts & Figures:• Research Team: 1 Group Leader, 6 Researchers, 1 PhD Researcher• R&D Assets: OpenGNSS, OpenGNSS Lite, OpenSDR, eOBU• Public Funded Research Projects: CYBERCARS2 (FP6), MOBILIZING
INTERNET (ITEA), MARTA, mVIA, NCV2015 (Spanish Programmes), INCAVE, i:MUGI (Basque Programmes)
Telecom – Wireless SystemsIntelligent Transport Communication Networks Group
