Raviranjan Kumar Singh Semminar Reprasention

8/7/2019 Raviranjan Kumar Singh Semminar Reprasention

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WELCOME


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SEMINAR REPORT

ON

LED - WIRELESS

SUBMITTED BY:-

RAVIRANJAN KU. SINGH

07012310978TH SEM

ECE


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INTRODUCTION

IN RECENT WORD THE NEW DEVLOPMENT INCOMMUNICATION WORLD THROUGH LED IS CALLED I-

LIGHT.

THIS LED TECNOLOGY IN COMMUNICATION IS

USED BECAUSE OF HIGH LUMINOUS EFFICANCY OF

LED DEVICE(LIKE AL-IN-GA-P),FAST SWITCHING AND

MODULATION VISIBLE LIGHT WAVE FOR FERR SPACE

COMMUNICATION.


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IN PLACEWEAREALSO USING THEIR(INFRARED RADIATION) BUTLED

COMMUNICATION HASSOMEADVANTANGE:-

LED

---------------------------------------------------------------1)THE I-LIGHT TRANSCEIVERS MAKE USE

OF THE DIRECT LINE OF SIGHT(LOS)

PROPERTY OF VISIBLE LIGHT, WHICH IS

IDEAL IN APPLICATION FOR PROVIDING

DIRECTIONAL GUIDENCE TO VISUAL

IMPAIRMENTS.

2)I-LIGHT IS EASY TO TARGETS FOR LOS

RECEPTION BY THE RECEIVER.

3)A USER SEARCHING FOR INFORMATION

HAS ONLY TO LOOK FOR LIGHT FROM AN I-

LIGHT TRASMITTER.

4)LED DEVICE IS CONCURRENTELY USE

FOR ILLUMINATION,DISPLAY OR VISUAL

SIGNAGE,FOR THIS NO NEED TO

IMPLEMENT TRANSMITTER FOR

INFORMATION BROADCASTING.

IR

----------------------------------------------------------

1)IR HAS THE PROPERTY OF

BOUNCING BACK AND FORTH

IN A CONFINED ENVIOOMENT.

2)THER IS SO MUCH

DIFFICULTIES TARGET BYRECEIVER.

3)DIFFICULTI TO FIND THE

DIRECTION OF SIGNAL BY

THE USER.

4)EXTRA DEVICE IS USINGFOR TRANSMITTER FOR

INFORMATION

BROADCASTING.


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COMPARISON TABLE


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SYSTEM DESCRIPTIONB THROUGH LED

COMMUNICATION

TRANSMITTER

RECIVER

TRANSMITTER :-


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RECIEVER:-


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PHOTODETECTOR

The photo detector circuit consists of a

photo diode and a resistor. One end of the

photo diode is coupled to the current limiting

resistor with the other end coupled to the

ground . The photo-detector is used to detecta light signal from the transmitter and

convert it into an electrical signal. The

limiting pre-amplifier is used to amplify the

electrical signal from the photo-detector for

the next stage. And it produce rectangular

signal pulses .


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DATA REPRODUCING CIRCUIT

The data reproducing circuit, which consists of anoperational amplifier, a resistor, and two NAND Schmitt

triggers is used.

Its function is to produce rectangular pulses from the

amplified signal in the previous stage.

An operational amplifier is used as a comparator,

which uses a virtual ground as a reference.

The NAND Schmitt trigger gates are used to enhance

the noise immunity and to correct the edges from low tohigh voltage levels due to slew rate of the amplifier.

Two NAND Schmitt trigger gates are used instead of

one so that the signal will not be inverted.


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DIFFERENTIATOR

Then, a differentiator circuit consistingof a capacitor and a resistor is used to

detect the leading edges of the pulse

with the trailing edge blocked by the

diode.

A Schmitt trigger gate is used as a

pulse generator, and the output gives the

inverted version of pulses from thedifferentiator.


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INTEGRATORANDENVELOPEDETECTOR

According to inverted pulse of differentiator ,it get

modulated signal would be reconstructed.

BAND PASS FILTER

The band pass filter is use to filter out high frequency

distortion and low frequency noise . And output from the

band pass filter is an audio signal.

POWERAMPLIFIER

It is use for the delivery of the audible messages

through a speaker or headphone.


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DIGITALDATA TRASMITTER THROUGH LED

A receiver, which resembles a portable traveler

location system, has been implemented to obtain the

demodulated signal.


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TRAFFIC INFORMATION SYSTEM

Vehicle Information & Communication System (VICS)is starting to become practicable .The Infrared

System of VICS detects vehicles on the road by using

optical beacons to control traffic and to supply real

time traffic information. But it is an enormous budget

because the optical beacon must be located on every

lane of the road throughout the country.

Under this background, the utilization of LED traffic

light to transmit information has been patented. This

is because LED traffic light use low power, have better

efficiency and have much longer lamp life. The

proposed setup of this system is shown in fig in whichtraffic light is the transmitter and receiver is fixed in

front of the vehicle


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IMPLEMENTATION & EXPERIMENTALRESULTSThe specification of led traffic signal head are given below :-


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BITERROR RATEEXPERIMENT

A bit error rate (BER) experiment for the LED traffic light has been

performed . In the experiment, frames of data were transmitted

continuously from a computer to the serial communication interface

circuit via the printer port of the computer. The modulated signal is

transmitted by the LED traffic light. The visible-light signal wastransmitted to the receiver, and the serial communication interface

performs demodulation of the data. The computer at the receiver

side would compare the received data with transmitted data. The

number of error bits would be recorded. BER is inversely proposal to

brightness


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APPLICATION OFVISIBLELEDSYSTEM

1) High-brightness LEDs are increasingly being used intraffic lights due to their low power consumption and

minimal required maintenance, which can be translated

into considerable cost savings each year. . LED power

consumption is only 8-12W, compared with around 150W

used by its incandescent counter part.

2) an LED traffic light can be used as an audio

broadcasting device, in addition to their normal function

of being an indication and signaling device.

3) museum or exhibit-hall environment. The information onan individual exhibit can be broadcast via a plurality of

LEDs, which is also used for the purpose of illumination.


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ADVANTAGESOFLEDSYSTEM

Like microwaves, visible-LED light beams follow astraight-line path and are well suited for the wireless

delivery of large quantities of voice and data information.

DISADVANTAGESOFLEDSYSTEM

1) They are suitable for short range.

2) the photo-detector current is proportional to the

received power.

3) that the relationship between the radiant intensity and

the distance from the receiver follows the inverse

square law.4) It is not suitable for broadcasting signals over a wide

coverage area or over long ranges. Because noise

arising from sunlight, incandescent lighting, and

fluorescent lighting.


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High brightness LEDs are getting more popular and are

opening up a number of new applications, especially with

the improved efficiency and new colors. In this article, the

novel idea is based on the fast switching of LEDs and the

modulation of visible light is developed into a new kind of

information system.

Any illumination device making using of high brightness

visible LEDs can be used as a kind of short-range

information beacon.. One example is an LED traffic light for

the support of roadside-to-vehicle communications. Thereare many potential novel uses of visible light from LEDs as

a communication medium. This concurrent use of LEDs for

simultaneous signaling and communications will open up

many new applications

CONCLUSION


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THANK-

YOU

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Raviranjan Kumar Singh Semminar Reprasention

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