assignment communication-2014.docx

8/18/2019 Assignment Communication-2014.docx

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CE00038-2-Communications Individual Assignment Page 1of 27

TABLE OF CONTENTS

S.NO CONTENTS Page no.

1. Acknowledgement…………………………………………………………………….3

2. Abstract………………………………………………………………………………..

3. Introduction of communication............................................................................................ !-"

. #ection 1…………………………………………………………………………… $"-

1%

a% &'at do (ou understand b( modulation and demodulation in communication s(stem)

*+,lain 'ow modulation makes ,ossible to transmit several modulating signals over a

common c'annel.

b% Classif( analog ,ulse modulation s(stems) Com,are t'em

c% ow digital modulation tec'niues are useful in communication s(stem) *+,lain t'e

different digital modulation tec'niues wit' block diagram.

d% /escribe t'e PC0 tec'niue along wit' e+,ression of signal to noise ratio wit' e+am,les.

e% /etermine t'e a,,lications w'ere t'ese tec'niues are used wit' t'e 'el, of diagram.

!. #ection 2. ………………………………………….……………………………..$1!-

2%

a. /o simulation for t'e /#-A0 modulator using simulink software 'avingsingle tone message signal of 1 and a sinusoidal carrier signal of

freuenc( 7 k modulated at modulation de,t's of .2!4 .!414 1.!4 2 and 1

b( var(ing t'e value of 5dc.

i. 6or eac' value of t'e modulation de,t's ,resent and anal(e t'e

modulated signal bot' in t'e time and in freuenc( domains.

ii. /erive suitable conclusions.

b. 0ake a s(nc'ronous demodulator model for t'e /#-A0 modulator of ,art

$a% at t'e same values of t'e modulation de,t's

1. Anal(ses and ,resent t'e demodulated signal bot' in freuenc(

and time domains.

2. /erive suitable conclusions.

c. iven a two P'ase modulator s'own in figure 2$a%. 8'e in,ut signal consists of

voice signal occu,(ing t'e freuenc( band .3 to 3. k. 8'e two oscillator

freuencies$9#C% 'ave t'e values f1:1k and f2:1 0. #,ecif( t'e

following;

i. #idebands of /##C modulated wave a,,earing at t'e two ,roduct

modulator out,ut.

ii. #idebands of ## modulated wave a,,earing at t'e two $band ,ass

filters% P6 out,uts.


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iii. 8'e ,ass band and guard bands of t'e two P6.

iv. Present and anal(ses all t'e results and derive suitable conclusions.

v. #'ow t'e waveforms.

6igure 2$a%

". >eferences………………………………………………………………………………2!


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ACKNOWLEDGEMENT

&e would like to take t'is o,,ortunit( to t'ank to t'ose su,,ortive and caring 'ands t'at were

t'ere wit' us during t'e com,letion of t'e w'ole Assignment. 6irst and foremost we would

like to begin wit' our =ecturer 0onika amb'ir for 'er ,recious su,,ort t'roug'out t'e w'oleAssignment ,re,aration. #'e was alwa(s t'ere to 'el, us in an( difficulties b( taking t'e ,ain

of c'ecking t'e ,ro?ect and correcting t'e mistakes. #'e ,rovided us wit' t'e most useful and

valuable guidelines about t'e Assignment matters wit'out w'ic' we couldn@t 'ave come u,

wit' successful ,a,er on time. #'e gave us t'e knowledge of eac' ever(t'ing related and

be(ond t'e module in order to en'ance our skills and t'is assignment 'as been made ,ossible

due to 'er e+,ertise and knowledge.

Also we would like to take t'is o,,ortunit( to t'anks t'e =ibrarian

and m( friends w'o 'ave been a source of motivation and ideas for t'eir 'el,.

/I=IP B0A>

$P812D2%


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CE00038-2-Communications Individual Assignment Page of 27

ABSTRACT

A communications s(stem is a collection of communications networks wit' t'e ca,abilit( of

interconnection and intero,eration to form an integrated w'ole.

Modua!"on "n #o$$un"#a!"on %&%!e$' - 0odulation is an im,ortant ste, of communication

s(stem. 0odulation is defined as t'e ,rocess w'ereb( some c'aracteristic line am,litude.

De$odua!"on "n #o$$un"#a!"on %&%!e$'-8'e 8ransferred of /emodulation is removed

from t'e carrier wave modulated wit' t'e information signal.

Anaog (u%e $odua!"on %&%!e$; - Pulse modulation s(stems4 instead of a continuous wave4

a train of ,ulse is em,lo(ed and some ,arameter of t'e ,ulse is varied in accordance wit' t'e

instantaneous value of t'e modulating signal.

PAM'- 8'e PA0 $Pulse am,litude modulation% is a modulation mode4 in w'ic' am,litude of

t'e carrier ,ulse train is varied according to t'e modulating signal.

D"g"!a $odua!"on'- /igital modulation tec'niues are useful in communication s(stem. 8'e

move to digital modulation ,rovides more information ca,acit(4 com,atibilit( wit' digital data

services4 'ig'er data securit(.

A$("!ude %)"*! +e&"ng ,ASK'- Am,litude-s'ift ke(ing $A#B% is a form of modulation t'at

re,resents digital data as variations in t'e am,litude of a carrier wave.

Fe/uen#& %)"*! +e&"ng $odua!"on ,FSK'- 6reuenc(-s'ift ke(ing $6#B% is a freuenc(

modulation sc'eme in w'ic' digital information is transmitted t'roug' discrete freuenc(

c'anges of a wave.

P)a%e %)"*! +e&"ng $odua!"on ,PSK %;- P'ase modulation P'ase-s'ift ke(ing $P#B% is a

digital modulation sc'eme based on c'anging4 or modulating4 t'e initial ,'ase of a carrier

signal.

Sa$("ng'-8'e ,rocess of generating ,ulses of ero widt' and of am,litude eual to t'e

instantaneous am,litude of t'e analog signal.

uan!"1a!"on'- >e,resentation of a continuousl( var(ing uantit( as one of a number of

discrete values.


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CE00038-2-Communications Individual Assignment Page !of 27

NTRODCTON OF COMMNCATON

A communications s(stem is a collection of communications networks wit' t'e ca,abilit( of

interconnection and intero,eration to form an integrated w'ole. 8'e ,ur,ose of a

communications s(stem is to serve a common ,ur,ose of effective communication and o,eratein unison. Introduction4 9rientation Introduction to communication s(stem4 Eeed for

modulation4 Am,litude modulation4 8ime domain and 6reuenc( domain descri,tion4 Power

relations in A0 wave4 #uare law modulator4 #witc'ing modulator4 /etection of A0 waves4

#uare law detector4 *nvelo,e detector .Eow a da(@s communication and modulation is one of

t'e basic reuirements of 'ig'er communication tec'niue. In t'is assignment we 'ave to

solve different ,roblems related to t'e communication met'ods and also we 'ave to s'ow

some modulation tec'niue b( simulation4 in t'e #I0=IEB of 0A8=A #oftware.

Eeed for modulation

/efinition of modulation

8(,es of modulation tec'niues F A04 604 P0

A0 definition - 8(,es of A0 F#tandard A04 /#4 ##4 and 5#

0odulation inde+ or de,t' of modulation and G modulation

#,ectra and andwidt' of all t(,es of A0

eneration of A0 wave using #uare law modulator #witc'ing modulator

eneration of /# wave using alanced modulator >ing modulator

/etection of A0 wave using #uare law detector *nvelo,e detector

Re%ea#) "dea *o #o$$un"#a!"on %&%!e$ *o a ne4 genea!"on'-

8'e transmission of information-bearing signal over a band ,ass communication c'annel4 suc'

as tele,'one line or a satellite c'annel usuall( reuires a s'ift of t'e range of freuencies

contained in t'e signal to anot'er freuenc( range suitable for transmission. A s'ift in t'e

signal freuenc( range is accom,lis'ed b( modulation. 8'is c'a,ter introduces t'e definitionof modulation4 need of modulation4 t(,es of modulation- A04 P0 and 604 5arious t(,es of

A04 s,ectra of A04 bandwidt' reuirements4 eneration of A0 /#-#C4 detection of A0

/#-#C4 and ,ower relations.

Co$$un"#a!"on Ne!4o+% need *o a ne4 genea!"on'-

Interfaces between wireless and guided media networks. Investigation of routing4 congestion4

and transmission control mec'anisms for networks ranging from wireless networks $suc' as

multic'i, ,acket radio networks4 wireless local area networks4 ,ersonal communications

networks and cellular tele,'on( networks% to 'ig'-s,eed guided media networks $suc' as


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CE00038-2-Communications Individual Assignment Page "of 27

fiber-o,tic A80 networks and multi- ,rocessor com,uter networks.%Performance of wireless

networks under c'anges in traffic4 interference and connectivit(. Interaction between c'annel

measurements and network ,rotocolsH su,,ort for multimedia traffic. 0et'ods to ,rovide

service guarantees for multi,le classes of traffic in guided media networks. 8ools used include

stoc'astic modeling and anal(sis4 o,timiation4 com,uter simulations4 estimation t'eor(4

combination4 and information t'eor(.

SECTON 5

5 a W)a! do &ou unde%!and 6& $odua!"on and de$odua!"on "n #o$$un"#a!"on

%&%!e$7 E(a"n )o4 $odua!"on $a+e% (o%%"6e !o !an%$"! %e9ea $odua!"ng %"gna%

o9e a #o$$on #)anne.

ANSWER' 5,a

Modua!"on "n #o$$un"#a!"on %&%!e$' - 0odulation is an im,ortant ste, of communication

s(stem. 0odulation is defined as t'e ,rocess w'ereb( some c'aracteristic line am,litude4

freuenc(4 ,'ase of a 'ig' freuenc( signal wave $carrier wave% is varied in accordance wit'

instantaneous value intensit( of low freuenc( signal wave $modulating wave.%

De$odua!"on "n #o$$un"#a!"on %&%!e$'-8'e 8ransferred of /emodulation is removed

from t'e carrier wave modulated wit' t'e information signal. 8'ere are different wa(s of

demodulation de,ending on 'ow t'e ,arameters of t'e base-band signal are transferred to t'e

carrier signal4 suc' as am,litude4 freuenc( or ,'ase. 6or e+am,le4 a signal modulated wit' a

linear configuration and A0 $Am,litude 0odulation%4 we can make a s(nc'ronous detector.

9n t'e ot'er 'and4 a modulated signal 'aving a modulation angle4 we need a 60 $6reuenc(

0odulation% demodulator or a clock $,'ase modulation% demodulator.

An A0 signal encodes t'e information onto t'e carrier wave b( var(ing its am,litude in direct

s(m,at'( wit' t'e analogue signal to be sent. 8'ere are two met'ods used to demodulate A0

signals. 8'e cr(stal set e+,loits t'e sim,licit( of A0 modulation to ,roduce a receiver wit'

ver( few ,arts4 using t'e cr(stal as t'e rectifier4 and t'e limited freuenc( res,onse of t'e

'ead,'ones as t'e filter.

8'e first met'od of demodulation is ver( sim,le met'od t'at is envelo,e detector. It 'as a

rectifier t'at ,asses current in one direction onl(4 and also a low ,ass filter. 8'e rectifier ma(

be in t'e form of a single diode4 or ma( be more com,le+. 0an( natural substances e+'ibit


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t'is rectification be'avior4 w'ic' is w'( it was t'e earliest modulation and demodulation

tec'niue used in radio. 8'e filter is usuall( a >C low - ,ass t(,e4 but t'e filter function can

sometimes be ac'ieved b( rel(ing on t'e limited freuenc( res,onse of t'e circuitr( following

t'e rectifier

Mu!"(e"ng Te#)n"/ue%'

• #'aring of a c'annel b( several user.

• C'annel wit' 'ig'er bandwidt'.

• Cost ,er bite is reduce.

• Cost of transmission reduce.

:o4 Modua!"on $a+e "! (o%%"6e !o !an%$"! %e9ea %"gna %"$u!aneou%&

1. 6reuenc( division multi,le+ing.

2. 8ime division multi,le+ing.

3. Code division multi,le+ing.$PE Code% or ,seudo code.

5 6 Ca%%"*& anaog (u%e $odua!"on %&%!e$%7 Co$(ae !)e$

ANSWER 5,6

Anaog (u%e $odua!"on %&%!e$; - Pulse modulation s(stems4 instead of a continuous wave4

a train of ,ulse is em,lo(ed and some ,arameter of t'e ,ulse is varied in accordance wit' t'e

instantaneous value of t'e modulating signal.


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CE00038-2-Communications Individual Assignment Page Dof 27

F"g.'-5 ,Ca%%"*"#a!"on o* PCM

Ca%%"*"#a!"on o* Anaog Pu%e Modua!"on

T)ee ae !4o (u%e $odua!"on

$1% Pulse am,litude modulation $PA0%

$2% Pulse duration modulation $P80%

5PAM'- 8'e PA0 $Pulse am,litude modulation% is a modulation mode4 in w'ic' am,litude

of t'e carrier ,ulse train is varied according to t'e modulating signal.

8P*# 96 PA0;-

a Na!ua PAM; Eatural PA0 sam,ling occurs w'en finite widt' ,ulses are used in t'e

modulation and to,s of ,ulses follow t'e modulating signal.

6 Fa! !o( PAM; In t'is4 met'od4 t'e ,ulses obtained are flat. 8'e ,ulses 'ave a constant

am,litude wit'in t'e ,ulse interval. It can easil( be ac'ieved b( a sam,le and 'old circuit

8'e flat to, PA0 is most ,o,ular and widel( used4 because during transmission t'e noise

interferes wit' t'e to, of t'e ,ulses. 8'is noise can be removed easil( if ,ulses 'ave a flat to,.

Ca%%"*"#a!"on o* PAM

$i% /ual ,olarit( PA0

$ii% #ingle ,olarit( PA04


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CE00038-2-Communications Individual Assignment Page Jof 27

2 PTM'- In Pulse time modulation $P80 % am,litude of t'e ,ulse is ke,t constant4 w'ereas

widt' or ,osition of t'e ,ulse is made ,ro,ortional to t'e am,litude of t'e message signal

T)e PTM )a% !4o !&(e%;

a% Pulse widt' modulation$P&0%

b% Pulse ,osition modulation$PP0%

a Pu%e 4"d!) $odua!"on;- In ,ulse widt' modulation $P&0%4t'e widt' of t'e carrier ,ulse is

varied according to t'e instantaneous value of t'e modulating signal4 w'ile t'e am,litude

remains constant. 8'is s(stem is also called KPulse duration modulationL $P/0% or

KPulse lengt' modulationL $P=0%.

6 Pu%e (o%"!"on $odua!"on ,PPM ' In t'is s(stem4 am,litude and widt' of t'e carrier ,ulses

are ke,t constant w'ile ,osition of eac' ,ulse wit' res,ect to t'e Position of a reference ,ulse

is varied in accordance to t'e message signal

COMPARE T:E PAM; PWM < PPM

S.no PAM PWM,PDM;PLM PPM

5. Am,litude of t'e carrier

,ulse is ,ro,ortional to t'e

am,litude of modulating

signal.

8'e widt' of t'e carrier ,ulse

is ,ro,ortional to t'e

am,litude of t'e modulating

signal.

8'e relative ,osition of

carrier ,ulse is

,ro,ortional to t'e

modulating signal.

2. 8'e bandwidt' of

t'e transmitting

c'annel de,ends

u,on t'e widt' of ,ulse.

8'e .w of t'e c'annel

de,ends u,on t'e ,ulse

.&:

&'ere t is t'e rise time.

8'e .w of t'e c'annel

de,ends u,on t'e rise of

t'e ,ulse. .&:

3. 8'e instantaneous ,ower of

t'e transmitter.

8'e instantaneous ,ower of

t'e transmitter.

8'e instantaneous

,ower of t'e transmitter

remains constant


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=. Eoise interface is 'ig' Eoise interface is =aw. Eoise interface is =aw.

> #imilar to

am,litude

modulation.

#imilar to

freuenc(

modulation.

#imilar to

P'ase

modulation.


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5.C :o4 d"g"!a $odua!"on !e#)n"/ue% ae u%e*u "n #o$$un"#a!"on %&%!e$7 E(a"n !)e

d"**een! d"g"!a $odua!"on !e#)n"/ue% 4"!) 6o#+ d"aga$.

ANSWER 5,C

DGTAL MODLATON TEC:NES SEFL N COMMNCATON

/igital modulation tec'niues are useful in communication s(stem. 8'e move to digital

modulation ,rovides more information ca,acit(4 com,atibilit( wit' digital data services4

'ig'er data securit(4 better ualit( communications4 and uicker s(stem availabilit(.

/evelo,ers of communications s(stems face t'ese constraints;

M Available bandwidt'

M Permissible ,ower

M In'erent noise level of t'e s(stem

8'e >6 s,ectrum must be s'ared4 (et ever( da( t'ere are more users for t'at s,ectrum as

demand for communications services increases. /igital modulation sc'emes 'ave greater

ca,acit( to conve( large amount of information t'an analog modulation sc'eme.

T)e d"g"!a $odua!"on !e#)n"/ue% ae'

1% Am,litude s'ift ke( modulation $A#B%

2% 6reuenc( s'ift ke( modulation $6#B%

3% P'ase s'ift ke(ing modulation $P#B%

5. A$("!ude %)"*! +e&"ng ,ASK'- Am,litude-s'ift ke(ing $A#B% is a form of modulation t'at

re,resents digital data as variations in t'e am,litude of a carrier wave.

An( digital modulation sc'eme uses a finite number of distinct signals to re,resent digital

data. A#B uses a finite number of am,litudes4 eac' assigned a uniue ,attern of binar( digits.

suall(4 eac' am,litude encodes an eual number of bits. *ac' ,attern of bits forms t'e

s(mbol t'at is re,resented b( t'e ,articular am,litude. 8'e demodulator4 w'ic' is designed

s,ecificall( for t'e s(mbol-set used b( t'e modulator4 determines t'e am,litude of t'e

received signal and ma,s it back to t'e s(mbol it re,resents4 t'us recovering t'e original data.

6reuenc( and ,'ase of t'e carrier are ke,t constant.


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F"g.2-Bo#+ d"aga$ o* ASK

2. Fe/uen#& %)"*! +e&"ng $odua!"on ,FSK'- 6reuenc(-s'ift ke(ing $6#B% is a freuenc(

modulation sc'eme in w'ic' digital information is transmitted t'roug' discrete freuenc(

c'anges of a wave. 8'e sim,lest 6#B is binar( 6#B $6#B%. 6#B uses a ,air of discrete

freuencies to transmit binar( $s and 1s% information. &it' t'is sc'eme4 t'e N1N is called t'e

mark freuenc( and t'e NN is called t'e s,ace freuenc(. 8'e time domain of an 6#B

modulated carrier is illustrated in t'e figures to t'e rig't.

F"g.3-Bo#+ d"aga$ o* FSK

3. P)a%e %)"*! +e&"ng $odua!"on ,PSK %;- P'ase modulation P'ase-s'ift ke(ing $P#B% is a

digital modulation sc'eme based on c'anging4 or modulating4 t'e initial ,'ase of a carrier

signal. P#B is used to re,resent digital information4 suc' as binar( digits ero $% and one $1%.

P#B uses a finite number of ,'asesH eac' assigned a uniue ,attern of binar( digit. suall(4

eac' ,'ase encodes an eual number of bits. *ac' ,attern of bits forms t'e re,resented b( t'e

,articular ,'ase. 8'e demodulation 4 w'ic' is designed s,ecificall( for t'e s(mbol-set used b(

t'e modulator4 determines t'e ,'ase of t'e received signal and ma,s it back to t'e s(mbol it

re,resents4 t'us recovering t'e original data.

F"g.=-Bo#+ d"aga$ o* PSK


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5 d De%#"6e !)e PCM !e#)n"/ue aong 4"!) e(e%%"on o* %"gna !o no"%e a!"o 4"!)

ea$(e%.

ANSWER 5,d

PLSE CODE MODLATON '-Pulse coded modulation is known as t'e digital Pulsecoded modulation s(stem. Pulse-Code 0odulation $PC0% is t'e most commonl( used digital

modulation sc'eme. In PC04 t'e available range of signal voltages is divided into levels and

eac' is assigned a binar( number. *ac' sam,le is re,resented b( a binar( number and

transmitted seriall(. 8'e number of levels available de,ends u,on t'e number of bits used to

e+,ress t'e sam,le value. 8'e number of levels is given b(; E : 2m. It consists of t'ree main

,arts i.e.4 transmitter4 transmission ,at' and receiver. 8'e essential o,erations in t'e

transmitter of a PC0 s(stem are sam,ling4 uantiing and encoding as discussed earlier4

sam,ling is t'e o,erating in w'ic' an analog signal is according to t'e sam,ling t'eorem

resulting in a discrete -time signal..

PCM #on%"%!% o* !)ee %!e(% !o d"g"!"1e an anaog %"gna'

1. #am,ling

2. Ouantiation3. inar( encoding

efore we sam,le4 we 'ave to filter t'e signal to limit t'e ma+imum freuenc( of t'e signal

.6iltering s'ould ensure t'at we do not distort t'e signal4 ie remove 'ig' freuenc(

com,onents t'at affect t'e signal s'a,e.

F"g.'- >


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Sa$("ng;-8'e ,rocess of generating ,ulses of ero widt' and of am,litude eual to t'e

instantaneous am,litude of t'e analog signal. 8'e no. of ,ulses ,er second is called Ksam,ling

rateL. A scientist b( t'e name of arr( E(uist discovered t'at t'e original analog signal can

be reconstructed if enoug' sam,les are taken. e determined t'at if t'e sam,ling freuenc( is

at least twice t'e 'ig'est freuenc( of t'e original in,ut analog voice signal4 t'is signal can be

reconstructed b( a low-,ass filter at t'e destination..

F"g. '-?,Ga() o* %a$("ng

uan!"1a!"on'- >e,resentation of a continuousl( var(ing uantit( as one of a number of

discrete values. 8'e ,rocess of dividing t'e ma+imum value of t'e analog signal into a fi+ed

no. of levels in order to convert t'e PA0 into a inar( Code. 8'e levels obtained are called

Kuantiation levelsL.

F"g.'-@,Ga() o* /uan!"1a!"on

( uantiing t'e PA0 ,ulse4 original signal is onl( a,,ro+imated.

8'e ,rocess of converting analog signals to PC0 is called uantiing.

#ince t'e original signal can 'ave an infinite number of signal levels4 t'e uantiing ,rocess will

,roduce errors called uantiing errors or uantiing noise.

B"na& en#od"ng'-


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CE00038-2-Communications Individual Assignment Page 1!of 27

F"g.'-8,Ga() o* 6"na& en#od"ng

5.e De!e$"ne !)e a(("#a!"on% 4)ee !)e%e !e#)n"/ue% ae u%ed 4"!) !)e )e( o* d"aga$.

ANSWER 5,e

/igital devices translate and reassemble data and in t'e ,rocess are more ,rone to loss of

ualit( as com,ared to analog devices. Com,uter advancement 'as enabled use of error

detection and error correction tec'niues to remove disturbances artificiall( from digital

signals and im,rove ualit(.

A(("#a!"on o* Anaog < D"g"!a Te#)n"/ue%

Anaog D"g"!a

#ignal Analog signal is a continuous

signal w'ic' re,resents

,'(sical measurements.

/igital signals are discrete

time signals generated b(

digital modulation.

&aves It is /enoted b( sine waves It is /enoted b( suare waves

>e,resentation ses continuous range of

values to re,resent

information

ses discrete or discontinuous

values to

re,resent information

*+am,le uman voice in air4 analog

electronic devices

Com,uters4 C/s4 /5/s4 and

ot'er digital electronic

devices.

8ec'nolog( Analog tec'nolog( records

waveforms as t'e( are.

#am,les analog waveforms

into a limited set of numbers

and records t'em.

/ata transmissions #ub?ected to deterioration b(

noise during transmission and

writeread c(cle

Can be noise-immune wit'out

deterioration during

transmission and writeread

c(cle.


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CE00038-2-Communications Individual Assignment Page 1"of 27

>es,onse to Eoise; 0ore likel( to get affected

reducing accurac(

=ess affected since noise

res,onse are analog in nature

SECTON'-2

2,a

ANSWER 2a,"

DSB AM MODLATOR

G"9en !)a!

0essage signal: 1 $=et .1 in t'e model%

Carrier signal : 7k $=et 7 in t'e model%

0odulation de,t' : .2!4 .!4 14 2 Mode'- modulating freuenc( :

1$.1 % Carrier freuenc( : 7k $7%


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F"g. '- MODEL OF DSB AM Modua!o

M0.2>

0odulation inde+ : .2! modulating freuenc( : 1 Carrier freuenc( : 7k

F"g.-50 Modua!ed 4a9e *o $0.2>

M0.>

0odulation inde+ : .! modulating freuenc( : 1 Carrier freuenc( : 7k


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CE00038-2-Communications Individual Assignment Page 1Dof 27

F"g.-55 Modua!ed 4a9e *o $ 0.>

M5

0odulation inde+ : 1 modulating freuenc( : 1 Carrier freuenc( : 7k

F"g.no-52 Modua!ed 4a9e *o $5

M5.>

0odulation inde+ : 1.! modulating freuenc( : 1 Carrier freuenc( : 7k


19/27

CE00038-2-Communications Individual Assignment Page 1Jof 27

F"g.-53 Modua!ed 4a9e *o $5.>

M2


F"g.'-5= Modua!ed 4a9e *o $2

2a,"" De"9e %u"!a6e #on#u%"on%.


20/27


ANSWER 2a,""

CONCLSON'-

In t'is above /#-A0 modulator I know t'at /# A0 modulator w'en I c'ange t'e

modulation de,t' t'e am,litude of t'e wave is also c'anged. I 'ave designed a /# A0

modulator on #imulink and give t'e ,arameters w'ic' are reuired for desired waves in

#imulink. I 'ave got man( waves on different modulation de,t's as .2!4.!4142 and

freuenc(.

26,"

ANSWER 2 6,"

DSB AM DEMODLATOR

G"9en !)a!

0essage signal: 1

Carrier signal : 7 k

0odulation de,t' : .2!4 .!4 14 2

Mode'- modulating freuenc( : 1$.1% Carrier freuenc( :

7k$7%


21/27


F"g.-5> MODEL DSB AM DEMODLATOR

M0.2>

0odulation inde+ : .2! modulating freuenc( : 1 Carrier freuenc( : 7k


22/27


F"g.'-5? De$odua!ed 4a9e *o $ 0.2>

M0.>

0odulation inde+ : .! modulating freuenc( : 1 Carrier freuenc( : 7k

F"g.'-5@ De$odua!ed 4a9e *o $ 0.>

M5



23/27


F"g.no-58 De$odua!ed 4a9e *o $ 5

M5.>

0odulation inde+ : 1.! modulating freuenc( : 1 Carrier freuenc( : 7k

F"g.no-5 De$odua!ed 4a9e *o $ 5.>

M2


24/27



F"g.'-20 De$odua!ed 4a9e *o $ 2

26,""

ANSWER 2 6,""

CONCLSON'-

In t'is above /#-A0 /emodulator. I know t'at /# A0 /emodulator w'en I c'ange t'e

modulation de,t' t'e am,litude of t'e wave is also c'anged. I 'ave designed a /# A0

/emodulator on #imulink and give t'e ,arameters w'ic' are reuired for desired waves in

#imulink. I 'ave got man( waves on different modulation de,t's as .2!4.!4142 and

freuenc(.

.


25/27

CE00038-2-Communications Individual Assignment Page 2!of 27

2C DSBSC MODLATON ANSWER

ANSWERE 2 C ,"

$i% #ideband of /##C modulated wave a,,earing at t'e two ,roduct modulator out,ut are;

9ut,ut at P01;

=ower sideband 1 B F 3 to 1 B F 3 B

JJ.7 B to J7 B

,,er sideband ; 1 B Q 3 to 1 B Q 3 B

1.3 B to 13 B 9ut,ut

at P02;

=ower sideband ; 1 0 F 1.3 B to 1 0 F 13 BJ.DJJ7 B to J.DJ7 B

,,er sideband ; 1 0 Q 1.3 B to 1 0 Q 13 B

1.13 0 to 1.13 0

ANSWER 2 C ,""

$ii%#idebands of ## modulated wave a,,earing at t'e two P6 out,uts are

9ut,ut at P61

,,er sideband ; 1.3 B to 13 B

9ut,ut at P62

,,er sideband ; 1.13 0 to 1.13 0

AE#&*> 2 C $iii%

$iii%Pass band for P61

1.3 B to 13 B

Pass band for P62

1.13 0 to 1.13 0

$iv% uard band for P61;

ig'est freuenc( com,onent of t'e lower sideband - =owest freuenc( com,onent of t'e u,,er

sideband : JJ.7 B to 1.3 B


26/27

CE00038-2-Communications Individual Assignment Page 2"of 27

uard band for P62;

ig'est freuenc( com,onent of t'e lower sideband - =owest freuenc( com,onent of t'e u,,er

sideband : J.DJJ7 0 to 1.13 0

ANSWER 2 C ,"9

Con#u%"on'-

In t'is above /##C modulator. I know t'at /##C modulator w'en I c'ange t'e modulation

de,t' t'e am,litude of t'e wave is also c'anged. I 'ave designed a /##C modulator on

#imulink and give t'e ,arameters w'ic' are reuired for desired waves in #imulink. I 'ave got

man( waves on different modulation de,t's and freuenc(.

ANSWER 2 C ,9

F"g.25 Mode o* DSBSC Modua!"on

WAEFOFM'-

F"g.

'-22 Wa9e*o$ o* DSBSC Modua!"on


27/27


REFERENCES

• #a'e. $23%4 Principles of Communication Systems43rd ed4 Eew /el'i4 80.

• a(kin .# &ile( R4$21%4 Principles of Communication Systems4 2nd *d4=ondon;

80.

• ari 'arti.B.E >ao .. $2J%. Analog communications4 2nd *d4 /el'i; Pearson

Publication.

• #ing >.P. #a,er #P4$27% Communication System4 #econd *dition4C'annai;80.

• =at'i..P4Communication Systems4!8 *d4$2J%4 /el'i;# Publication.

• #'arma.#.4 $2J%4Communication System Analog and Digital 4 4 !t' *d. Eew /el'i; #.B.

Bataria #ons4 Eew /el'i.

• &aggener. $2D%. Pulse Code Modulation Techniques. "t' ed. =ondan; #,ringer

#cience usiness 0edi. ,3!-137.

• #ing'.>.P4 #a,re.#./ $2D%. Communication Systems. 7t' ed. Eew /el'i; 8ata 0craw-

ill *ducation. ,!-7D

• #c'wart.04ennett.&.>4 #tein.# $2J%. Communication Systems and Techniques. 2nd

ed. Eew ork; Ro'n &ile( #ons. ,1"7-"J.

• BA=.# $2J%. BASIC ELECT!"ICS# DE$ICES% CIC&ITS A"D IT

'&"DAME"TALS . 3rd ed. Eew /el'i; PI =earning Pvt. =td.. ,!-"!.

• 0odulation 8ec'niues - P&0 and Pulse Code 0odulation. 21. 0odulation

8ec'niues - P&0 and Pulse Code 0odulation. S9E=IE*T Available at;

'tt,;www.electronics'ub.orgmodulation-and-different-t(,es-ofmodulation.

SAccessed 1 Eovember 21T.

• &'at is 0odulation 8ec'niues and 8(,es wit' A,,lications. 21. &'at is 0odulation

8ec'niues and 8(,es wit' A,,lications. S9E=IE*T Available at;

'tt,;www.edgef+.int(,es-of-modulation-tec'niues-wit'-a,,lications.

SAccessed 1" october21T.

assignment communication-2014.docx

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