SMART TRANSMITTER ANDRECEIVER FOR UNDERWATER

NAME-RITU BHARTIREGD NO-1301216166BRANCH-ETEFINAL YEAR STUDENT GUIDED BY-”DEVASIS

PRADHAN SIR”PADMANAVA COLLEGE OF

ENGINEERING,ROURKELA

RITUBHARTI

CONTENTS INTRODUCTION PROPERTIES EXPERIMENTAL STUDY SMART TRANSMITTER SMART RECEIVER ADVANTAGES STUDY APPLICATION FUTURE SCOPE CONCLUSION REFERENCE

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 Smart Transmitter

PROPERTIES Beam Attenuation Coefficientc(λ)=a(λ)+b(λ)

Single- Scattering Albedoω o ≡ b  ( λ )/ c  ( λ )    Volume Scattering Functionβ  ( ψ , λ ) =  ( Φ s  ( ψ , λ ) /Φ i  ( λ ) )   Ω r

EXPERIMENTAL STUDY A 3.66m long,1.22m wide,1.22m tall

indoor water tank constructed. Maalox – controls attenuation

coefficient of water. Nigrosin dyein-controls albedo.

1000 GALLON WATER TANK

Relation between attenuation coefficient and SNR for experiment in laboratory test tank.

SMART RECEIVER Goal-to develop a quasi

omnidirectional system that reduces pointing and tracking requirements.

Characteristics• Increased FOV• Angle of arrival estimation

DESIGN 3-D spherical array of lenses all

focusing to a 2-D planar array of photodiodes.

A prototype constructed using seven lenses and seven photodiodes.

Lens at the receiver Research in the domain of indoor

Optical wireless in use of sphericalPhotodiode arrays for increasing

FOV. Existing optical front-end arrays use

• Photodiode arrays with no lenses.• Single lens with multiple photodiodes.

• Multiple lenses focusing on separate photodiodes.

Angle Of Arrival Estimation Intensity of light receivedPhotodiode output combining Connect the array of photodiodes in

parallel An ideal combining techniqueLinear diversity combining

technique Equal Gain Combining(EGC)

y=y1+y2+…..+yn Maximum selection combining(SEL)

Y=max(y1,y2……..yn)

SMART TRANSMITTER Characteristics Increased directionality. Electronic switchedBeamsteering Design Consists of a truncated Hexagonal pyramid with sevenLEDs Each LED is coupled with its own lens that

converges the wide FOV of the LED to a narrow beam in a particular direction

STUDY Angle of arrival Estimation-direction

based on relative output power Backscatter estimation-observe

relationship between attenuation coefficient and backscattered light collected

RESULTS OF EXPERIMENTS

(a)Estimates vs true angle(b)Bias of the estimation

Results of backscatter estimation experiment

ADVANTAGES Non-mechanical pointing and

tracking on it allows for moving underwater vehicle.

Providing sensory information to underwater vehicles.

Duplex multi-user system Spatial diversity Monitor optical

backscattering

APPLICATION OF TX AND RX Transmitter Signal transmitter FM transmitter:-1. New 2000 FM radio

tx 2. Smart bluetooth FMTx in car with 2-ways

plug USB car charger.

Pressure transmitter-MPM480 pressure transmitter.

Receiver Use of styled-

media Receiver Develop custom

Receiver Media player

library Default media

Receiver

FUTURE SCOPE OF TX AND RX An Adaptive Network Coded

Retransmission Scheme for Single-Hop Wireless Multicast Broadcast Services.

A survey of multipoint relay based broadcast schemes in wireless ad hoc networks.

On broadcasting with cooperative diversity in multi-hop wireless networks.

Improving cell broadcasting scheme to support multi-lingual service in wireless networks.

CONCLUSION 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 transmitter allows electronic

switched beamsteering.

REFERENCE

[1] Simpson, Jim. A; Hughes,Brian L; Muth,John F “Smart transmitters and receivers for underwater free-space optical communication,”IEEE Journal on selected areas in communications, VOL. 30, NO. 5, JUNE 2012 .

[2] Pontbriand, N. Farr, J. Ware, J. Presig and H. Popenoe, “Diffuse high-bandwidth optical communications,” in Proc. OCEANS Conf, 2008, Quebec, Canada, Sept. 15-18 2008.

[3] B. Cochenour, L. Mullen, and A. Laux, “Phase Coherent Digital Communications for Wireless Optical Links in Turbid Underwater Environments,” in Proc. OCEANS Conf. 2007, Vancouver, BC, Canada, 2007.

[4] M. Doniec, I. Vasilescu, M. Chitre, C. Detweiler, M. HoffmannKuhnt, and D. Rus, “AquaOptical: A lightweight device for high-rate longrange underwater point-to-point communication,” in Proc. OCEANS Conf. 2009, Biloxi, MS, Oct 26-29 2009.

[5] F. Hanson and S. Radic, “High bandwidth underwater optical communication,” Applied Optics, vol. 47, no. 2, p. 277.