1
Asier Alonso Muñoz
Intelligent 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
The next “big thing” ?
V2V
SAFETY
R2V
EFFICIENCY
I2V
V2U
COMFORT & INFOTAINMENT
The Fully Networked Car
Geneva, 4-5 March 2009
NAVIGATION & TRACKING
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Probably!, 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
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Our 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
5
… and here it comes SDR !
o One device per
 One single device
waveform
integrating multiple
radios
o Many Hw components  Single programmable
device (FPGA, DSP)
Amplifying +
Filtering +
Downconverting
Traditional SDR platform scheme
The Fully Networked Car
Geneva, 4-5 March 2009
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What 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
The Fully Networked Car
Geneva, 4-5 March 2009
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SDR-based On-Board Hw Architecture
General
purpose
I/O
Memory Elements
Processor
RAM Unit
Signal Processing
Ext. Memory Card
Acquisition Unit
Parts (ADC/DAC)
Digitization parts
RF Front
Front-end
-End
The Fully Networked Car
Geneva, 4-5 March 2009
Clock Mgmt Unit
Oscillator
Processing Unit
Clock
Distributor
Ethernet
External Interfaces
USB
JTAG
PROM
Configuration Unit
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Signal 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
Receiver Front-End
LNA
BPF
ADC
• Choice of an appropriate sampling frequency
• Digital front-end design
The Fully Networked Car
Geneva, 4-5 March 2009
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Sampling Frequency Choice
o Bandpass sampling allows supressing analog
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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
Sampling Frequency Choice (cont’d)
o Example: GNSS signals GPS (L1) & Galileo
(E5a/b)  Full Bw = 400 MHz
The Fully Networked Car
Geneva, 4-5 March 2009
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Sampling Frequency Choice (cont’d)
o Final frequency after aliasing is:
Fal = M*Fs ± Fo
o Our goal was to match Galileo and GPS
central frequencies so we obtain:
-N*Fs+FGPS=M*Fs-FGal
The Fully Networked Car
Geneva, 4-5 March 2009
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Sampling Frequency Choice (cont’d)
7 possible sampling
frequencies :
GPS L1
(MHz)
Galileo
E5a
(MHz)
Final Bw = 60 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
-50
-55
-60
-65
-70
P(dBm)
Fs
(MHz)
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-75
-80
-85
-90
The Fully Networked Car
Geneva, 4-5 March 2009
-95
-100
0
10
20
30
40
f(MHz)
50
60
70
80
Digital Front-End Design
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o Each GNSS signal is processed independently
o Each band is processed with a standard
downsampling scheme
The Fully Networked Car
Geneva, 4-5 March 2009
Results
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)
The Fully Networked Car
Geneva, 4-5 March 2009
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Results (cont’d)
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o Dynamic range tests: If signal power
decreases  undesired spurious signals
Received spectrum for a input CNR= -20 dB
-30
-40
-50
Level(dBm)
-60
-70
-80
-90
-100
-110
-120
-130
0
1
2
3
4
f(Hz)
5
6
7
8
6
x 10
Dynamic range = 40 dB = ADC’s DR
The Fully Networked Car
Geneva, 4-5 March 2009
Conclusions
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
The Fully Networked Car
Geneva, 4-5 March 2009
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Next 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
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Thank you !
Asier Alonso Muñoz
Intelligent Transport Communication Networks Researcher
TECNALIA TELECOM
aalonso@robotiker.es
www.tecnalia.es/telecom
www.robotiker.es
The Fully Networked Car
Geneva, 4-5 March 2009
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Backup
Slides
The Fully Networked Car
Geneva, 4-5 March 2009
TECNALIA Telecom
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Business Unit of TECNALIA for the Telecommunications Sector
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, Publicfunded 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.
The Fully Networked Car
Geneva, 4-5 March 2009
Telecom – Wireless Systems
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Intelligent Transport Communication Networks Group
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)
The Fully Networked Car
Geneva, 4-5 March 2009