Transcript New Generation ITS Communications Katsuyoshi Sato

AP-NeGeMo
New
Generation ITS
Communications
Katsuyoshi Sato
National Institute of Information and
Communications Technology (NICT), IAI, Japan
Study on ITS telecommunication system
Millimeter wave ROF road-vehicle
communication system
・Multi-service
・high speed data transmission
Millimeter wave inter vehicle
communication system
・integrated radar communication system
・safe operational support
What is Inter-Vehicle Communication (IVC)?

Running vehicles on traffic road communicate each other
directly for driving support.

The applications using IVC are Automatic Cruse Control
(ACC), Collision Avoidance, Multimedia (Inter-vehicle
Karaoke ), e.t.c. .

Short range communication ( ~ 100 m )
Keywords

Inter-vehicle communication

Millimeter wave (60 GHz)

Propagation characteristics (fading, two ray model )

Data transmission experiments ( 1 - 10 Mbps )
Driving Support using Inter-Vehicle Communication
Why millimeter wave ( MM wave) ?

High-efficiency of frequency reuse due to high
attenuation compared with microwave (DSRC)

Low attenuation caused by rain, fog, and snow
compared with optical communications

Potential of wide-band transmission

Sharing of RF section between IVC system and
radar system for collision avoidance

Minaiturization of RF section
Problems on design of IVC system using MM wave

Rapid changes in signal strength (Fading)

Large Doppler-shift

Strong shadowing effect

Interference between cells

Large frequency drift of RF sections

Cost reduction
Research on IVC in NICT

Measurement of propagation characteristics of 60 GHz
millimeter wave on the road, expressway, e.t.c. .


Estimation of inter-vehicle wireless data transmission
between running vehicles.


Propagation model between vehicles on the road, Fading
effect, Doppler-shift, Diversity effect, Polarization effect
Characteristics of received power vs. bit error rate, Effect of
space diversity Mod./Demod., Error correction
System design for IVC system using millimeter wave

Feasibility study of IVC using millimeter wave,
Standardization, Reflection into laws and regulations
Measurement of propagation characteristics

Static condition (without fading )

Receieved power, bit error rate (BER) vs. distance

Comparison between result & propagation model

Effect of space diversity
Building
Bank
Vacant
lot
Test Course
(200m)
Rx
Parking
Lot
Vacant
Lot
Tx
Baseball
Ground
Experimental facility
Experimental condition
Center freqency
59.1 GHz
Transmitted power
-4 dBm or +9 dBm
Data rate
1 Mbps or 10 Mbps
Modulation
DFSK (manchester code)
Detection
Differential
Antenna
Standard Horn
Antenna gain
24 dBi
Polarization
Vertical or Horizontal
Diversity thrshold (Level)
-70 dBm
Diversity thrshold (Def.)
10 dB
Diversity timing delay
10 micro seconds
Main points of measurements

Dependence of antenna height and distance between
vehicles

Confirmation of two-ray propagation model

Estimation of space diversity

Dependence of polarization
Two ray model
Pt Gt Gr   2 2 2 ht hr 
Pr 
sin 


L(d) 2 d
d 
Received power
d
Tx
Rx
direct wave
ht
hr
reflected wave
（ reflection coeficient = -1 ）
Two ray model （assumption )

Reflection coefficient of pavement = -1

Roughness of pavement was ignored

Directivity of antennas was ignored

Absorption of Oxygen @60 GHz = 16 dB/km
Test course
Building
Bank
Vacant
lot
Building
Test Course
(200m)
Rx
Prefablication
Parking
Lot
Vacant
Lot
Tx
Baseball
Ground
Resuls （V-pol）
Results （Rxh = diversity, V-pol ）
Shadowing effect ( Sedan )
Inter-vehicle data transmission on expressway

Experiments of data
transmission on the expressway.

Two vehicle run on the same
lane in Yokohama-Yokosuka
expressway at 80 km/h with the
distance of about 100 m.

Received power and BER were
measured.

Effect of space diversity also
confirmed.
Measurement in expressway
Measurement results in expressway
Cumulative distribution of received power
Whole data
Without Shadowing
Cumulative distribution of BER
Regulation of 60 GHz band in Japan ( Aug. 9, 2000 )

59 GHz - 66 GHz ( Unlicensed band )
( ref. 60GHz - 61 GHz for Radar )

Picture transmission or data transmission

Band width < 2.5 GHz / 1 channel

Frequency variation < 500 ppm

Transmission power < 10 mW

Antenna gain < 47 dBi
Target system of IVC (provisional)

Frrequency : 60 GHz band

Cell size : 100 m - 150 m ( Line Of Sight)

Data rate : 1 Mbps - 10 Mbps (air rate )
( image )

Power : 10 mW, Antenna Gain : 20 - 30 dBi

Low-cost, small-size, high-reliability

(Option) : Fusion between IVC & Radar system (60 GHz)
Experiment
Shadowing effect
Radar and Transponder system (Vehicle Safety System)
Integrated communication unit
with radar (Scanning Antenna)
Transponder unit
Radar and Transponder system

Transmission rate: 100kbps

BER (typ.) less than 10-4

Comm. range: 100m

Frequency: 60GHz

Antenna beam width
3deg.(Radar)
30deg.(Transponder)

Rader type: FM-CW

FM sweep range: 100MHz
Radar
Transponder
specifications
Integrated Communication
unit
Transmission rate
100kbps
Transmission method
half-duplex
less than 1.00E-04
BER
Communication range
100m
Operating frequency
60GHz band
Output Power
Multiplex method
Modulation
Demodulation
Transponder unit
3.0mW(4.8dBm)
Time division / superimposed
2FSK/AM
Homodyne detection
/FSK demodulation
Envelope detection
/FSK demodulation
3°
－
30dB
－
Rader type
FM-CW
－
FM sweep range
100MHz
－
150×250×120mm
190×165×63mm
Antenna beam width
Antenna gain
dimensions
Examples of application




radio wave markers (road signs)
support for safe driving in converging traffic
intersection safety
rear-end collision alarm
radio wave markers (road signs)
transponder
support for safe driving in converging traffic
Transponder
トラポン
intersection safety
Transponder
rear-end collision alarm
Transponder
Future work for realization of IVC system

Detail investigation of propagation (fading)

Measure against frequency drift of RF sections
( Mod. / Demod., EC, Sync., e.t.c. )

Access method ( multiple access )

Cost reduction

Popularization strategy

Fusion between IVC system & radar system
Road-Vehicle communication



Millimeter-wave spot communication system
high speed data transmission
multi-service
Specification








down link: 59.0-60.0 GHz
up link: 61.0-62.0 GHz
RF power: 10 dBm
FDD
antenna gain: 14dBm(base station), 11dBm(mobile
station)
modulation: D-BPSK
band width: 270MHz
data rate: 155.52Mbps
ROF spot communication system
Control station
Base station
Mobile station
Antenna
12cmx18cmx6cm
Packet Error Rate
０．５ｍ
１５ｍ
1.00E+00
1.00E+00
1.00E-01
1.00E-01
1.00E-02
1.00E-02
PＥＲ
ＰＥＲ
１５ｍ
1.00E-03
1.00E-03
1.00E-04
1.00E-04
1.00E-05
1.00E-05
1.00E-06
1.00E-06
-80
-70
-60
-50
-40
ＩＮＰＵＴ ＬＥＶＥＬ［ｄＢｍ］
down link
-30
-20
-80
-70
-60
-50
-40
ＩＮＰＵＴ ＬＥＶＥＬ［ｄＢｍ］
up link
-30
-20
Experiment configuration
Antenna pattern
Calculated received power (4.5 m height base station)
Experiment
Base station
Base station
2.5ｍ
4.5ｍ
18.3°
Received power
-40
-50
Power [dB]
-60
-70
-80
-90
0.00m
1.25m
2.50m
3.75m
5.00m
-100
-110
-120
-2
0
2
4
6
D istance [m ]
8
10
12
Packet Error Rate
1.00E+00
1.00E-01
FER
1.00E-02
1.00E-03
1.00E-04
1.00E-05
1.00E-06
0
2
4
6
Distance [m]
8
10
12
PER and received power
Dynamic and Autonomous Multi-Hop Communication System for Advanced Customer-Provided Mobile
Communications on VHF Band