New　 Generation ITS　 Communications

Katsuyoshi Sato National Institute of Information and Communication

s Technology (NICT), IAI, Japan

AP-NeGeMo

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. . Propagation model between vehicles on the road, Fading

effect, Doppler-shift, Diversity effect, Polarization effect Estimation of inter-vehicle wireless data transmission betw

een running vehicles. 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 diversityBank

Baseball Ground

Building

Test Course (200m)

Parking Lot

Vacant Lot

TxRxVacant

lot

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

Dependence of antenna height and distance between vehicles

Confirmation of two-ray propagation model

Estimation of space diversity

Dependence of polarization

Main points of measurements

Two ray model

direct wave

reflected wave 　（ reflection coeficient = -1 ）

Tx Rxd

ht hr

Received power Pr PtGt Gr

L(d)

2d

2

sin2 2hthr

d

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

Bank

Baseball Ground

Building

Test Course (200m)

Parking Lot

Vacant Lot

TxRxVacant

lot

Prefablication

Building

Resuls 　（ V-pol ）

-100

-90

-80

-70

-60

-50

-40

-30

200150100500

Horizontal Distance [m]

10-10

10-8

10-6

10-4

10-2

100

Txh = 46 cmRxh = 85 cmV-pol

Power(Measured) Power(model) BER

-100

-90

-80

-70

-60

-50

-40

-30

200150100500

Horizontal Distance [m]

10-10

10-8

10-6

10-4

10-2

100

Txh = 46 cmRxh = 38 cmV-pol

Power(Measured) Power(model) BER

Results 　（ Rxh = diversity, V-pol ）

-100

-90

-80

-70

-60

-50

-40

-30

200150100500

Horizontal Distance [m]

10-10

10-8

10-6

10-4

10-2

100

Txh = 46 cmRxh =diversity V-pol

Power(h=85cm) Power(h=38cm) Power(diversity) BER(diversity)

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

0.1

2

4

6

1

2

4

6

10

2

4

6

100

-50 -40 -30 -20 -10 0 10 20

Received Power (reffered to median) [dB]

RxH=83.6 cm RxH=36.1 cm Diversity Rayleigh

0.1

2

4

6

1

2

4

6

10

2

4

6

100

-50 -40 -30 -20 -10 0 10 20

Received Power (reffered to median) [dB]

RxH=83.6 cm RxH=36.1 cm Diversity Rayleigh

Without ShadowingWhole data

Cumulative distribution of BER

100

80

60

40

20

0

-8 -6 -4 -2 0Exponent of BER

FREE

1 Mbps RxH = 83.6 cm RxH = 36.1 cm Diversity

100

80

60

40

20

0

-8 -6 -4 -2 0Exponent of BER

FREE

10 Mbps RxH=83.6 cm RxH=36.1 cm Diversity

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 )

Power : 10 mW, Antenna Gain : 20 - 30 dBi

Low-cost, small-size, high-reliability

(Option) : Fusion between IVC & Radar system (60 GHz)

( image )

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.(Transponde

r)

Rader type: FM-CW

FM sweep range: 100MHz

Transponder

Radar

Integrated Communication unit

Transponder unit

Transmission rate 100kbps

Transmission method half-duplex

BER less than 1.00E-04

Communication range 100m

Operating frequency 60GHz band

Output Power 3.0mW(4.8dBm)

Multiplex method Time division / superimposed

Modulation 2FSK/AM

Demodulation Homodyne detection

/FSK demodulation

Envelope detection

/FSK demodulation

Antenna beam width 3° －Antenna gain 30dB －Rader type FM-CW －FM sweep range 100MHz －dimensions 150×250×120mm 190×165×63mm

specifications

Examples of application

radio wave markers (road signs)radio wave markers (road signs) support for safe driving in converging trafficsupport for safe driving in converging traffic intersection safetyintersection safety rear-end collision alarmrear-end collision alarm

radio wave markers (road signs)

transponder

support for safe driving in converging traffic

トラポン

Transponder

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 statio

n)

modulation: D-BPSK band width: 270MHz data rate: 155.52Mbps

ROF spot communication system

12cmx18cmx6cm

Base stationControl station

Mobile station

Antenna

Packet Error Rate

down link up link

1.00E- 06

1.00E- 05

1.00E- 04

1.00E- 03

1.00E- 02

1.00E- 01

1.00E+00

- 80 - 70 - 60 - 50 - 40 - 30 - 20

ＩＮＰＵＴＬＥＶＥＬ［ｄＢｍ］PＥ

Ｒ

1.00E- 06

1.00E- 05

1.00E- 04

1.00E- 03

1.00E- 02

1.00E- 01

1.00E+00

- 80 - 70 - 60 - 50 - 40 - 30 - 20

ＩＮＰＵＴＬＥＶＥＬ［ｄＢｍ］

ＰＥ

Ｒ

１５ｍ

０．５ｍ

１５ｍ

Experiment configuration

Antenna pattern

Calculated received power (4.5 m height base station)

Experiment

Base station

2.5ｍ18.3°

4.5ｍ

Base station

Received power

- 120

- 110

- 100

- 90

- 80

- 70

- 60

- 50

- 40

- 2 0 2 4 6 8 10 12

Distance [m]

Pow

er

[dB

]

0.00m1.25m2.50m3.75m5.00m

Packet Error Rate

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

0 2 4 6 8 10 12

Distance [m]

FER

PER and received power

Dynamic and Autonomous Multi-Hop Communication System for Advanced Customer-Provided Mobile Communications on VHF Band