report on digital signal(bpsk,qpsk) generation,transmission & reception (200)

8/13/2019 Report on Digital Signal(Bpsk,Qpsk) Generation,Transmission & Reception (200)

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SUBMITTED BY:RAMRATAN MAHATOPAPIYA DASSUBHAMAY DASSUPRATIM SADHUKHANUDAY BHANU SEN

PPT ON DIGITALSIGNAL(BPSK,QPSK)

GENERATION,TRANSMISSION& RECEPTION


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INTRODUCTION

In satellite or telecommunication system, modulation is the process of conveying a

message signal over a medium. To extend the range of the analog signal or digital data,

we need to transmit it through a medium other than air. The process of converting

information so that it can be successfully transmitted through a medium is called

modulation. We are working with BPSK & QPSK modulation which is kind of a digital

modulation. Before going into the main focus we shall have a brief discussion on

modulation, different types of modulation and the analysis of it. This chapter gives a

brief and basic idea on modulation and different types of modulation techniques.


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PURPOSE OF MODULATION

Ease of radiation

Simultaneous transmission of severalsignals.

Reduction of Antenna Size.


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Modulation

Modulation is defined as the process by which some charactristics ofthe carrier is varied in accordance with the modulating signal.

Modulation Can be of two types..

1.Analog

2.Digital.

Digital Modulation means the amplitude, frequency or phase of thecarrier is switched depending on the input digitalsignal.(ASK,FSK,PSK).

In BPSK according to the label change of the symbol(1-0 or 0-1) the

phase of carrier is changed by 180 degree. In QPSK, the successive bits are coupled generating four symbols.(10

00 01 11).the phase shift in carrier become 45, 135, 225, 315 degreerespectively.


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BPSK

In a BPSK the binary symbols 1 & 0 modulate the phase of the carrier.

Carrier

s(t)=Acos(2*pi*f*t)

The power dissipated can be expressed as,

P=1/2(A*A)

so,

s1(t)=2P cos(2*pi*f*t) (for symbol 1)

s2(t)=2P cos(2*pi*f*t+pi) (for symbol 0)

s2(t)= -2P cos(2*pi*f*t)

In generalize,

s(t)=b(t) 2P cos(2*pi*f*t)

b(t)=+1 (when symbol 1 transmitted)

b(t)= -1 (when symbol 0 transmitted)


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BPSK GENERATION


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WORKING PRINCIPLE


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BPSK PRACTICAL CIRCUIT


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RANDOM SEQUENCE GENERATOR

Its a digital pulse train generator

It simulates the data to be transmitted

The more number of D latches usedhere,the longer the random sequence willbe.


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RANDOM SEQUENCE GENERATOR CIRCUIT


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BPSK WAVEFORM

Diagram of

Binary Sequence& Thecorresponding

Bipolar Signal.


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IC-741 OP AMP SPECIFICATION

PIN CONFIGURATION 1,5=offset null

2=inverting input

3=non-inverting input

4=v-

6=output

7=v+

8=nc

Performance range=(0-70 degree)

Overload protection on input andoutput

Supply voltage is 22v Differential input voltage 30v.


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CD4016 IC specification

Wide range of supply voltage(3-15V)

Wide range of digital & analogswitching.

ON resistance is 400 ohm.

High degree of linearity.Extremelylow off switch voltage.


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D FLIP FLOP IC SPECIFICATION

Its a dual positive edge triggerd Dtype flip flop.

Here SET & RESET areasynchronous active low inputs &operate independently of the clockinput.

Clock triggering occurs at voltagelevel & is not directly related totransition time of positive edgepulse.


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D FLIP FLOP IC SPECIFICATION

Its a 14 pin ic.

Range of Vcc=5v(+10 -10%)

1D & 2D=Data inputs

1Ck &2ck=clock input.

1Q,2Q,1Q &2Q=Data outputs

CLR1 &CLR2=Reset inputs

1PR & 2PR=Preset inputs


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SUBSEQUENT PART & QPSK


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QPSK

In QPSK two successive bits are combined together This produce four different symbols.(10 00 01 11).

When the symbol is changed to next symbol,the

phase of carrier is changed by 45 deg


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CONCLUSION

We would like to express our gratitude to ourrespected mam Dr. Kabita Purkait for guidance and

valuable suggestions and inspirations through outthe process.

We give our admiration to our lab assistant Nimaich. Pal.we are also thankful to HOD sir Dr.Achintyakr. Das along with all the faculty members of ECE

department.


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B O O K S :

[ 1 ] T H E O D O R E S . R A P P A P O R T , W I R E L E S SC O M M U N I C A T I O N S , P R I N C I P L E S A N D P R A C T I C E .

P R E N T I C E H A L L I N D I A , 2 0 0 2

[ 2 ] J . W . M A R K A N D W . Z H U A N G , W I R E L E S SC O M M U N I C A T I O N A N D N E T W O R K , P R E N T I C E

H A L L , 2 0 0 2

[ 3 ] S C H W A R T Z , M . I N F O R M A T I O NT R A N S M I S S I O N , M O D U L A T I O N A N D N O I S E ,

M C G R A W H I L L , N E W Y O R K , 1 9 9 0

LIST OF REFERENCE


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report on digital signal(bpsk,qpsk) generation,transmission & reception (200)

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