28-08-2014, 02:20 PM
SMART TRANSMITTERS AND RECEIVERS
FOR UNDERWATER COMMUNICATION
SMART TRANSMITTERS.pdf (Size: 453.8 KB / Downloads: 926)
Introduction
Underwater Freespace optical communication-Promising
alternative for Short range links.
Considered to be point to point.
New optical front-end proposed-the concept of smart
transmitters and receivers .
Smart Receivers-capable of detecting angle of arrival of signals.
Smart tranmitters
Electronically steers output beam towards particular direction.
Estimates water quality from back scattered light
Advantages
Non-mechanical pointing and tracking on a moving underwater
vehicle.
Providing sensory information to underwater vehicles.
Duplex multi-user system
Spatial diversity allows for simultaneous reception from two non
co-located transmitters.
Monitors optical backscattering while transmitter is active.
Smart Transmitters
Characteristics
increased directionality.
electronic switched beamsteering.
Design
Consists of a truncated hexagonal pyramid with seven LEDs.
Each LED is coupled with its own lens that converges the wide FOV
of the LED to a narrower beam in a particular direction.
Summary
Results show that design also capable of acting as smart system.
Backscatter estimation experiment demonstrates linear relationship
between return beam intensity and channel attenuation coefficient.
smart receivers
increased field of view
ability to estimate angle of arrival.
Smart transmitters allows electronic switched beamsteering