Communications Research Laboratory

1

Frequency Spectrum of Pulse

Frequencies which give zero spectrum are

Spectrum of Pulse　with time adulation τ　 is

（ n: Integer）

パルス信号の波形

パルス信号のスペクトル

F ( ) f ( t )

e j t d t

A / 2

/ 2

e j t d t

=A

- j e

j t

2 ej

t

2

A s i n

2

2

= A s i n f f

f n

f n

1

1

2

2

3

3

A

0

f (t)

2 20

時間

周波数

time

Frequency

Pulse waveform

Frequency spectrum of Pulse

Communications Research Laboratory

2Where do mobile communications go?ー Broadband, Different Systems and Internetー

Towards Broadband communications– High data rate>>>Wide frequency band>>>MM-

wave– Personal>>>Compact size terminals>>>small

devices Integrated Systems

– Mobile, Wireless LAN, Wireless Access, Home link Connection to Broadband Backbone Networks

– Access to the broadband Internet

Communications Research Laboratory

3

Trends of Wireless Access Systems in the World

5 GHz-band （ 5.15- 5.25 GHz ： 100 MHz)– USA (IEEE 802.11) ： 20 Mbps, OFDM– Europe (HIPERLAN-2, ETSI BRAN) ： 20 Mbps, ATM– Japan (MPT) ： 20 Mbps, 20 MHz/ch, OFDM

Millimeter-wave （ 40 ／ 60 GHz bands ）– SAMBA ： For vehicular in 40GHz band– MEDIAN ： High speed wireless LAN in 60GHz band– MMAC : High speed wireless LAN in 60GHz band

Satellite system （ Ka-band 、 Millimeter-wave ）– Teledesic ： Inter-satellite communication in MM-wave– M-Star: 52Mbps in 50/40 GHz

Communications Research Laboratory

4Multimedia Mobile Access Communication Systems (MMAC)

Main mission– MMAC are Mobile Communication Systems which can transmit ultra high

speed, high quality Multimedia Information "anytime and anywhere" with seamless connections to optical fiber networks.

High speed Wireless Access– Frequency: 5/25/40/60 GHz– Data rate（ Quasi-fixed）

» 2000 : 25Mbps» 2010 : 156Mbps 　　

Ultra high speed LAN– Frequency : 60 GHz– Data rate

» 2000 : 156Mbps» 2010 : 622Mbps

printed from MMAC

f=5 GHz or 60 GHzData=100 Mbps

f=60 GHzData=156 Mbps

f=5 GHzData=25 Mbps

f=25GHz Data=25 Mbps

Communications Research Laboratory

5

Millimeter-Wave Video Home Link Systems

Broadcast

Video Distribution in a House

Home Theater

TV on a Wall

PC

IF

Glass Vision

Computer

Portable TV

CS

BS

Signal Processing UnitPlanar Antenna

MMICPower Supply

Home Base Station

Communications Research Laboratory

6Millimeter-Wave Video Home Link Systems-Demonstration experiments inside a real house-

Received TV program of BS satellite.Transmitter is fixed on a top of a wall.

Receiver

Received TV program through a wall.(Transmitter is located in a next room.)

Transmitter

Communications Research Laboratory

7

Optical CableRadio on Fiber

RF/Opt. Conv.Antenna

60GHz Intervehicle

36~37GHz Road-to-Vehicle

Experimental Course at YRP

ITS NW

IMT-2000NW

1.5GHzPDCNW

1.9GHzPHSNW

BS

BS BS

Frequency integratingConverter

CentralControl Station

RF/Opt. Conv.

Receiving Station

12GHz Satellite TV

YRPBldg.

Intelligent Transport Systems