Current Status of Radio Wireless Communication § Limited bandwidth
§ Interference
q How to use the limited bandwidth more efficiently or find other communication media
q How to prevent radio interference
Limited bandwidth
Share
Base station
Relay station Microwave oven
Pace maker
Future Vision of Optical Wireless Communications (OWC)
§ For long distance communications, an communication link is mostly implemented using infrared
laser light . Developments in outdoor free space optical communication are limited by Point-to-Point wireless link
§ There are many applications witch need Point to Multi-Point communication (e.g. IPTV broadcast system)
The Problems of Outdoor Communication
Point-to-Point Connection
q How to find a solution to make the light go in different directions Chapter 3
The Problems of Indoor Communication
§ For indoor optical wireless communication system, diffused links is mostly implemented to make the system more robust
q How to find a solution to achieve a power efficient communication avoiding interference between different transmitters
q How to compile the optical wireless system and current radio system and how to have flexibility in deploying the system
Proposed System Model Station A
Fixed Reflector Array Optical Wireless Head
Station B Station C
Hub Station
Rotating Reflector Remote Station
Fixed Reflector C
Fixed Reflector A
Fixed Reflector B
Motor
SD/TDMA ;
Space Division/Time Division Multiple Access
Optical Wireless Head
Measurement System
APD LD
E/O LD APD
O/E
AGC E/O
E/O O/E
Received Level Monitor
Error Detector
O/E
Pattern Generator
Wave Length : 780nm, 830nm
Maximum Throughput : 156Mb/s
Transmit Distance : 2000m（max）
AGC : Automatic Gain Control Amplifier
APD : Avalanche Photo Diode
LD : Laser Diode
E/O : Electric-to-Optic Converter
O/E : Optic-to-Electric Converter
Hub station Remote station
Experiment Set-up
Motor Controller
Optical Wireless Transceiver
Stepping Motor
Fixed Reflector Array
Rotating Reflector
Fixed Reflector Array Rotating Reflector
Operation Device
