Digital Comm Basic

אאאא

אא

אאא المؤسسة العامة للتعليم الفني والتدريب المهني

אאאא

٢٣٢٣٧٧

א אא א ٢٣٧

،،אא،אW

אאאאאאאאאאאאאאאאאא،א

א אאאאאאאאאאא

Kאא

אאאאאאאא،אאא

،אאאאאאאאא א ،א אא אאאאאאאאאאאא

אא،אאאא،אK

א א ? אא ? ? א?אאאאאאאK

א א א א א אא،א،אאאא

אאאאאK

אאאאאK

אאאא

א אא א ٢٣٧

אאאאאאאK א،אאא

אאאאאאאאאאאאאאK

אאאאאאKאא

אא،אאK אאאאאאאאK

אאאאW

J אאאאאאא،אאא

J אאאאאאאאא

J אאאאאאאאא J אאאאFאE> J אK

אאאא

אKאאאK

א אא א ٢٣٧

אאאאKW • אא • אאא • א • אאא • אאF٠5VEאא

אF٠١EאאאאאKאאא٠١

אאK • אאאאאאFrepeatersEא

אאאאאK אאW • אאאא • אאאאK

אאאאאא

אאאאאאKאאאאאאא،א

אאאK

אאאאאאKא،אאאKא

אאא،אאאאK

א אא א ٢٣٧

אאאKאאאW

J אאWא J אאWאא J אאWאא

אאאאאא

J א J א J אK

אאא

J א J

אאאאאאאאאאאאאאא

אאא،FאאEאאאKW

J אאא Jאאא

،אאאאW J אאא J אאא J אאא

א אא א ٢٣٧

אאאאאאאאאאאאK

אFאE

אאאKאאW J א،אאאאאאא

אאאא،א J אאאאאא

אאאאאאאאאא

אאאאאK

אאאאאKאאאאאאאאאא

،אאאאאאאKאאאאא،אאאא

אאאאאאאK

אא،אאאאאאאאK

אא

אאאא


אאאא

א

١

א אא אא א ٢٣٧ א

- ١ -

אאWא Sampling

אאWאאאאאא

אאאאאאFאאKEאאאא

אאאאKאאאאאאא

אאאאKאאאK

אאWאאא٩٠K٪

אאW١٢

אאWאאKאאאK

אאWאאאאאK


- ٢ -

Vs(t) = V(t) * P(t)

١ J١אW

FSampling Theorem or Shannon TheoremE אאאא fm fs2fm،

אאאאK ،אאאא

אא(base band signal)אאאWאא

fs ≥ 2fmF١ J١E Wfsאא

fmאא אTs

1/fsZTsF١ J٢E WאאאאW ١E א ٢E אאא1/2fm ٣E אאאאK

א(aliasing error)א،אאא

אfm٢אאFNyquist

frequencyE، fs min= fN = 2fm

) ٣-١( TN = 1 / 2fm

W fN FNyquist frequencyE TNאK אאאV(t)P(t)א

אאVs(t)Fsampled signalKEא١א J١K )٣-١E


- ٣ -

א (אא)

א (א)

V(t)

(a)

V(f)

- fm 0 fm f (a/)

P(t) = a0+ ∑an cos 2π nfs t Ts 2Ts …… t

(b)

P(f) 2fs 3fs

- fs

(b/)

VS(t) = V(t) P(t) = V(t) a0 + ∑an V(t) cos(2π nfst) (c)

VS(f) = a0V(f) + ∑an V(f – nfs) -fm fm fs-fm fs+fm 2fs 3fs (c/)

١-١אWאאאא


- ٤ -

א (gating)Fאא sampleא hold אKEא١ J١K

אWאאאאאK

١E V(f)אאאאV(t)אfm–fm

١א J٢Wאא

٢E P(t) ) ٤-١(

٣E א

) ٥-١(

٤E אV(t)cos(2π nfst)

א١–٥אא

אcos(2π nfst)אא،nfsאnאאW

) ٦-١(

FWאא١–١E אאא١א J١אאFא

אאanalog signal base band signal orEa0a0V(t)אאאא١א J٥K

١E א،אאאאאfs ≥ 2fm

P(t) = a0+ ∑ an cos 2π n fs t

VS(t) = S(t) P(t) = a0V(t) + ∑an V(t) cos(2π nfst)

VS(f) = a0V(f) + ∑an V(f – nfs)


- ٥ -

٢E ،א

אאאאא ٣E אאאα 0 V(t)

א • אTsאfsאFV(f)

אאאE • א،Tsאfsא

FV(f)אאאE،אאאKאfs ═2fmא

אאK

١ J٢אFAliasingE אאאאאאאFEאאא،

אא١א J٣אאא،K

אאאאאאאאאאאאאאא

Kא،FAliasing errorsKE

١א–٣WאFאאאאKE

fs < 2fm


- ٦ -

،אא ١E אאאFlow pass filter LPFE

אאFanti-aliasing filterKE

٢E אFcut off frequency fcut offEאאfmax )٧-١( fcut off ≤ fmax

אאאא Nא،

אtp • fsא،אאאא

F١ J٨E

١ J٣WאFTypes of samplingE אK

١ J٣ J١WאאאFWIdeal samplingE

אאFunit weighted pulsesKEאאאFPAMKEא١א–٤K

N = fs tp = tp / Ts


- ٧ -

אאאא١

אאאאא

V(f) f

-fm fm )(1)( nfsf

TfP −= ∑δ

f -fs 0 fs 2fs 3fs ∑ −= )(1)( nfsfV

TfVs

-fm fm fs-fm fs+fm ………………….

V (t) t

( ) ( )∑+∞

−∞=

−=Ρn

nTstt δδ

Ts t Vs(t) = V(t) Pδ(t) t

١א J٤Wאאא

١ J٣ J٢אאאFNatural samplingE אאאאא

אKא١ J٥אK


- ٨ -

١א J5Wאא

אW ١E WאאFFETEא ٢E א ٣E אא،K

١ J٣ Jא٣אאFflat-top samplingE

אאאאאאאאFא١ J٥KE

אאאאאאFsample

and hold circuitFKEא١ J7KE


- ٩ -

١א J6Wא

אאאא١

אאאאא

V(f) -fm fm P(f) ∑ −= )()( nfsffSa

Tδτπτ

X X ∑+ )()(0 fanVfVa

∑

∑∞+

∞

+∞

−∞=

+=

−⎟⎠⎞

⎜⎝⎛=

-n

n

V(f-nfs)α V(f) α

nfsfVT

nSaT

fVs

0

)()( πττ

+3fs -fs -fm fm fs

V(t) t P(t) τ Vs(t)=P(t) * V(t)


- ١٠ -

١א J7Wאאאא

אW ١E אאFFETEא ٢E א ٣E אא،K ٤E אאאFFETEאFsampleEאCא

FholdKE אאא١ J٧Kא

אאאאאאאאK


- ١١ -

١א J8Wאאא

١ J٤אא

١E אאPAMאאFbase bandEאאאאאאfsFKאא

١ J٤E ٢E אאאאאא

xxxc sin)(sin =א

xKא،אאא ٣E אאאW

F١ J٩E

א אK1אאאאFcut off

frequency fcut offKE

τ1KBT =


- ١٢ -

אאPAMW אאאPCM אאTDM

١ J١ V(t)א fs =

5KHz،τ = 40µsK FאEאאFאאE FEאאK1 = 0.5K1 = 1.0K

FEאא25 KHz אK

١ J٢ V(t)א٠8KHzK

FאEאאאאא FEאאא

١ J٣ V(t)אאא١ J١א

א6אKHzK

FWאאאאאאאK


- ١٣ -

١ J٤

V(t)،אdc4 kHz KאאאאKא

א٥٠אK٪

FאEא

FEאא

١ J٥

א١٠٠٠٠אF10000 HzKEאא،אאFאאא

אאאguard bandE4KHzK

١ J٦

fs=9KHz،fm، fs- fmfm٢٥K٪

١ J٧

א500 Hz0.25ms Kאאאא18KHzאK


- ١٤ -

١ J٨

1 KHz2 KHzK0.1msאKאאאא35KHzK

١ J٥אאאאאאא (TDM of PAM signals)

אאאאWאאאאאאKאאKא

אFsequentiallyKE אאאאאאא Wאא

אאK

١א J٩Wא

אW ١E אFאE>Ts،

אא،אאאK ٢E אאאאאא، ٣E אאאאאא،אאKKKK ٤E אאאאFE، ٥E אא،אאאK


- ١٥ -

١ J٥ J١אאW E אאאאW

F١E אא

אא١ J٩אV1(t)V2(t)K

١א J١٠Wאא

א١٢אא •

،אאאא • אFTsKE

אאאאאK

F٢Eאאא אאאאsignal

#1signal #4FKאE> • אFcommutatorEאא

FdecommutatorEאK אא،אא •

א،אאא١ J11 אאK


- ١٦ -

من إشارتين بطريقة التقسيم الزمني وباستعمال جامع ومفكك أآثر تجميع :١١-١ الشكل

F٣E אאאאאאא

אFsampling theoremEא(fN = 2fm).

F٤E אאאאאאאאא

F٥E א١ J١١٧א٧ אאא

אאאא= Ts/7τאאKאאאK

אאאאאאK F٦E אאKאאא

אאאא١ J١٢K


- ١٧ -

١א J١٢W٧אא

אא

F١Eאאאא،אאאאאא

Tframeτ١K

F١Eאאא • fs = fN= 2fm • אא • א

• אאאτ5.0

=BאN

אאאWτTsk =

١א J١٣Wאk אאאK


- ١٨ -

אW FE kא،fm

אאאאK

FE אאאW

)١٠-١( fs = 2fm, Ts = , Tframe =

FE kאא

א

)١١-١( τ =

FE

)١٢-١( B = = = =

= = 0.5 k (2fm) = k X fm

BT = k fm for the ration B =

)١٣-١( BT = 2k fm.

E= אFאאאא אאאXאאאK

12fm

1 2fm

0.5 τ

0.5Ts/k

0.5 Tframe

k

0.5kTs

Tframek

0.5k 1/2fm

1τ


- ١٩ -

W • אאאא،אאאא، • אא،אאאW

Jfs = 2fm BT = L X fmF١ J١٤E

L = number of spaces + sync + data pulses

fs > 2fm

BT = L xF١ J١٥E

א١ J٩W

٧א PAMאאאאאBW = 1 kHzאא،K

Fs2


- ٢٠ -

١א J١٠W٧א PAMאאאאאאא١ J١٢אא،W

١א J١٤٧אאא

Fs = 1.25 fN

אאאEא

Eאא،אאאאאK

E אאאאאW (Multiplexing of dissimilar channels)

אאאאאאאKאאאאאאאFsub and super commutationKE


- ٢١ -

١E אאא • אאאא

• אאFfixed rateE • אאאא

٢E אאאא

• אאא • אאאאK

8 kHz15.5 kHz،16 kHzK אאאW

אאאאאאW אאאא

Jא80 kHz Jא40 kHz J١٨10 kHz J٨א1250 Hz

J١٦625 Hz אא١٦אא١ J١٤K

١א J١٥Wאאאאא٣٢


- ٢٢ -

؟א אW

E א٦٢٥Kאאאא E אאאא١٠٠٠٠א E ،אאאאאא

J א١٨10 kHzאא،אאא

J א40 kHz٤،אא

J א40 kHz٤،אא

J א80 kHz8،אא

J א40 kHz٤،אא

אאאאאא10 kHz،א

J אאא1250 Hz،א J אאא625 Hz16K

אאאא1250 Hzא١٢٥٠،א אא0.1 msK

אאא625 Hzא625،אאא0.2 msK


- ٢٣ -

١ J١١W

PAM/TDM ٦אא2 ττKאאאτKאאאFאKE>

אאאאא1

kHzK

١א J١٦٦אאK

FEאאfs = 1.5 fNK

،אאאאאאאאא

١ J١٢W

א١ J١١fs = 2fNK


- ٢٤ -

١ J٦אא (Pulse Analog Modulation)

١ J٦ J١W אא:א

אFamplitudeEאאFduration or widthEאFpositionEאK

• א(Pulse Amplitude Modulation: PAM) אאFאאאאאEא

אSTs(t) אאאK Pulse height = V α Vs

אאאt VαאK

• א(Pulse Width Modulation: PWM)

אFאאאאאEאאSTs(t) אאאK

Pulse width = τα Vs

Vsאאאt τα אK

• א(Pulse Position Modulation: PPM) אאFאאאא

אאאאEאאSTs(t) אאאK

Pulse position = td Vs Vsאאאt

td אK

א١ J١٦אאאאK


- ٢٥ -

١א J١٧אאאאK

• אא:

WאאEא o אאאאא o אאאאאא

אאאאא EאW o אאK

١ J٦ J٢א (Pulse Amplitude Modulation: PAM)אEא

אאFאאאאאEאאSTs(t) אאאK

• א،א

E א (Pulse Width Modulation: PWM)

(Pulse Duration Modulation: PDM)


- ٢٦ -

אFEאאSTs(t) אאאK

• ،א،א • ،אא،

אאא • אK

א١ J١٨אאK

١א J١٨אK

אW ١E ،אאאSTs(t)=1א،

٢E STs(t)=2אא،א

STs(t)=1، ٣E אאאK

אאאאא١ J١٩

١א J١٩אאא

Wאא،א

אאאאK


- ٢٧ -

E א (Pulse Position Modulation: PPM)

אFEאאSTs(t) אאאK • אאא،א • אאא

אאא • אא

אאאאאאאאFאEאK

• אאאאW

o אאאאאא o אאאK

אאאW א١ J٢٠אאאאKא١ J٢١אאא

WאאKאא ١K PAMאאS1(t) ٢K אאאFramp generatorEאS2(t) ٣K S1(t) S2(t) S3(t)

S1(t) = S2(t) + S3(t) ٤K אאS3(t) אאא ٥K אאFsaw toothEא(comparator)אא Vcc

> Vref S3(t)٠אאאאאPWM S4(t). ٦K FdifferentiatorEאאאא)S5(t)E

PPMS6(t)K


- ٢٨ -

א١ J٢٠אאאאK


- ٢٩ -

١א J٢١אאאאאK


- ٣٠ -

١ J٧אאאא (Demodulation of PAM and PWM and PPM) ١ J٧ J١אאW

١E אאא،אFLPFE،

١א J٢٢אאאPAMאK

٢E א FinstantaneousEא א ، אFshaped transfer characteristicsEא

FequalizerE،

١א J٢٣אאאPAMאK

٣E אאא E אאPAM PAM K

١ J٧ J٢אא אPWM إلى PAM אאFintegratorE

• א Fintegration Eא Fsample point E אאK،א،אא


- ٣١ -

• אאאאאאא،א

• א ١ J٢٣א Kא אW

E אאאאא

E אPAMאK ١ J٧ J٣אא

• אא • אאא • אPPM אאPWM،

אאאPWM إلى PAMK • אא١ J٢٤

١א J٢٤אPWMPPMPAMK

PPM

PWM

PAM

Ts 2Ts 3Ts 4T

Ts 2Ts 3Ts 4T

t

t

t

אאאא

אאאא


אאאא

א

א

٢

א אא אא א ٢٣٧ אא

- ٣٢ -

אאWאא Digital modulation

אאWאאאאאאאאא

FאאאאKEאאאKאאאאאK

אאKאאאאאאאK

אאWאאא٩٠K٪

אאW١٥

אאWאא

אאWאאאאאאא

אK


- ٣٣ -

٢–١אאא

אאWאאFEאאKאאאאאאא

אאאK

א٢–١אאאאאK

٢ J١ J١א–א؟ אW

١K אאאאEFאאאאאאאאאאא

، ٢K אאאא،אאא

אאאאאא،

٣K אאאאאא،

אאאא

אאאאאאאK אאאאאא

אאאאאK


- ٣٤ -

٢א–١Wאאא

אW

א،K

٢ J١ J٢אאW ١K אאאאאאאFBand

pass filterE אאאאאאFcut frequency fmE ٢K אfs fs≥fN، ٣K אאFPAMEאFPCMEא

FEncoderEFSampleEאFCode WordEF٨KE


- ٣٥ -

٤K –אWאאFquantization levelsE،אא

٥K אאF٠ J١٠EFאEאאאFquantization intervalE،

• א٢2nn،אא • n=8א٢٥٦F28E אאאא٠

٢٥٥K ٦K –אW،אא٠

אF٢٥٥EאאאאאFEאאאFCode WordE،

٢ J١ J٣אא

M،אא،אNאא،

( J١ 2)……….M = 2N

١E אאMאNW

(2-2)…….N = Log2M = 3.32 Log10M

٢–١W אאFnormalized PCME٢٥٦M=

א N = log2256= log228=8 bit

٢–٢W אא،אK

٦٤}٦אאאא،٧KאFN=7E128 = 27 = 2N

١٠٠K


- ٣٦ -

٢–١ אNN=100

٢–٢

٨٣K

٢א J٢Wאא

٢E אאאאאא

אFLow Pass Filter LPFKE

٢ J١ J٤א ١E אFPCMEאא

אFAnalog signalEאאFPAM

signalKE ٢E אאfmK

fN=2fm


- ٣٧ -

א2fmfs=fN= אRb = Nfs = 2Nfm

אWBT = Rb = 2Nfm

٢ J٣W אאאא

fm=4 KHZ, n=8 א

٢ J١ J٥א

٧K אאאאאאאFD/A converterE

אFquantization intervalE،א٢–٢

١E אW • אא-V+V

V V2 א

• NאאאW

(2-5) ……… voltsVN2

2=∆

• אא

volts n

Vnv

22/

22

2==

∆

• אא (2-6)……………NQ= V2/22N watts

• אLא


- ٣٨ -

( ) NNQ

VVNQSQ

NS 2

2

22 2

2=⎟⎟

⎠

⎞⎜⎜⎝

⎛÷==∴

(2-7)…………….. ( ) N

QNS 22=∴

אאאאאאKאא

אא

אאFNon linear amplifierEFcharacteristicEאאאK

WאאאאאK א٢–٣אאK


- ٣٩ -

٢א J٣אא

٢ J١ J٦א

١E אאFאEאאאאא،

٢E אאאאא

٣E א • א • אK

٢ J٤W

Kא FאEא FEא١٠ FEא FEאLא

JPS/QN JSNR= 22NN=10 bit

FEאאא40dB


- ٤٠ -

٢ J١ J٧אאא ١E אאאא

(2-8)……… )1ln(

1lnmax

max00 µ

µ

+

⎟⎟⎠

⎞⎜⎜⎝

⎛+

=Vi

Vi

VV for Vi ≥ 0

Viא V0א

Vimaxאא V0maxאא

µ אFcompression parameterE F٢٥٥E

٢א–٤Wאאא

٢E אאא

א ٣E אאא

אW

(2-9)……….. 0)1( max0max ≥⎥⎥

⎦

⎤

⎢⎢

⎣

⎡+=

⎥⎦

⎤⎢⎣

⎡

rV

V

iie forVVV

r

µµ


- ٤١ -

Vieאאא

٤E אאאאFאL

codec: coder/decoderKE

’א–א’A law (Europe) codecW

signAAxVV ⎟⎟

⎠

⎞⎜⎜⎝

⎛++

=lg1lg1

max00 1/A < X <1…….(2-10)

⎟⎟⎠

⎞⎜⎜⎝

⎛+ AAxVlg1max0 0 < X < 1/A…..(2-11)

A = 87.6

٢א J٥W

אא Vimax =8V, V0max = 5V, µ=255

אא2v4v8v

٢ J١ J٨אאא ١E אאאM ٢E אLאא M ٣E אM

٨٩ J א٥}١٢٪ J א٥٠٪

אאאK


- ٤٢ -

٢–١ J٩אא

אאאאא،אאאFnormalized valuesEאאאא١K

אאאאW

.... 20 10, 5, ,5.2V where, (t) X

converter A/D of voltagescale-full voltageanalog I/P actual voltageanalog I/P normalizes

fs ==

=

fsVVi

אL،א

fsVtX ×=

⎥⎦

⎤⎢⎣

⎡×⎥⎦

⎤⎢⎣

⎡=⎥

⎦

⎤⎢⎣

⎡

)(V converterD/A of voltagescale full

worddigital of valuenormalized

voltageanalogputout actual

o

אLאK

אאאLאW אאFunipolar encodingEאא٠}٠٠}١

אאFbipolar encodingEאא٠}١ J٠}١KH

אאאא٤٠١٦K


- ٤٣ -

א

א

א

7/8=0.875 6/8=0.75 5/8=0.625 4/8=0.5

3/8=0.375 2/8=0.25 1/8=0.125

0 -1/8=-0.125 -2/8=-0.25

-3/8=-0.375 -4/8=-0.5

-5/8=-0.625 -6/8=-0.75

-7/8=-0.875 -8/8=-1

15/16=0.9375 14/16=0.875 13/16=0.8125

12/16=0.75 11/16=0.6875 10/16=0.625 9/16=0.5625

8/16=0.5 7/16=0.4375 6/16=0.375

5/16=0.3125 4/16=0.25

3/16=0.1875 2/16=0.125

1/16=0.0625 0

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

1111 1110 1101 1100 1011 1010 1001 1000 0111 0110 0101 0100 0011 0010 0001 0000

٢א J١Wאאאאאא

א٤K

٢ J١ J٩ Jא ١אא

١E אאFאאE אא1X0 is )( signal normalized theof range the <≤∴ tX

١אא ٢E ٤162N 4 ==∴אאא٢ J

١אאאאאא٠}٠٠}١Fאא٠}١EאאW


- ٤٤ -

אאאאא אא

FXnE 0000 0123 20202020 ×+×+×+×016

0 = 1000

MSBKKKKLSB820202021 0123 =×+×+×+×5.0

168=

א١١١١א٠}١אא

1111 1521212121 0123 =×+×+×+×9375.0

1615

=

٣E אא

FKKKKKKKKKKKKKKKKKK٢ J١٣E NXu

21

=∆

٤E אא

NV

uVu fs

2V fs =×∆=∆FKKKKKKKKKKKKKKKKKK١٤–٢E

VfsאK ٥E ١אW

2N1-1u-1 (max) =×∆=XuFKKKKKKKKKK٢ J١٥E

W J א٠}١ J אאא J אאאאMSB=0אF١٠٠٠

٤E


- ٤٥ -

٦E א E אא٢ J٥

E אאאאאאא

אאאאאאא

E אאאאא

JאEאאאF1.67/16א2/161.47/16א1/16E

JEאאF1.67/16א1/16E

א٢ J٥אא٤

٢א J٥Wאא٤א


- ٤٦ -

٧E א

אEF א–א

error. normalizedunipolar peak theEu :Where

22

122

12

u Eu )1(1

=

==×

=×∆

=∴ +−+

NNNFKKKKKKKKK٢ J١٦E

Jאאאא

fs)1(

1fs V .22

V +−+ === n

nfsV

EuulFKKKKKKKKKKKKKKKKKK٢ J١٧E

٢ J٦W

L٦אאאא٠٢٠א

אK FאEאאu×∆ FEאאVu∆ FE Xu(max) FE Vu(max) FEEu FEul

٢ J١ J٩ Jא ٢אא ١E אאא ٢E א1-א+1 11 <≤− X

٣E ٤،٢٤١٦אא٢ J١K


- ٤٧ -

אאא

EXbF אא

Xb א

.

188

−=− 0000

K K K

K K K

K K K

0

1000

K K K

K K K

K K K

875.087= 1111

٢א J١Wאאאאאא٤

٤E אא)( bX∆Fא1 LSBE

F٢ J١٧E 11 2

21 +−− ==∆ n

nbX

٥E אאbV∆

fsN

Nfs

fsbb VV

VXV 11 2

2 +−

− ==∆=∆F٢ J١٨E

٦E אאאאאאאאאאאא

1211(max) +−−=∆−= Nbb XXF٢ J١٩E


- ٤٨ -

FWא٢ J١E • ٨

F٢ J٢٠E 122

−= NM

• ٨

F٢ J٢١E 1212

1 −=− −NM

א١٠٠٠אאא٠אMSB

אאא٢EFאאMSBא

88

811001

870001

⎪⎭

⎪⎬⎫

→

−→ 8

8

8601008

2010 1

⎭⎬⎫

⎢⎢

⎣

⎡

−→

→

MSB

ariescomplementF٢ J٢٢E

٧E א٢ J٦אאא ٨E א

• אאאאאb∆Ε

٢ J٢٣ Nbb

X −=∆

=∆Ε 22

• אאאאא

fsN

fsbb VVE −== 2 l٢ J٢٤


- ٤٩ -

٢–٢א אWאאאא

K

٢ J٢ J١אאאאאאא ١E אאdcאW

• אאF-V+VE ١0V٠

• א +V١-V

F٠E Wאאאאאdcאא

אאאא،א

٢E אduty cycleWאא


- ٥٠ -

• אNRZאאא • RZאאא

٣E אWא • אא • אאאאא

٤E אאאאWאאאאאאKאא،אא

אאאאאKאאאאFBPRZE

K

٥E אא • אאאאא

א • אUPNRZUPRZBPNRZBPRא،

BPRZ-AMIא،FKEאא BPRZ-AMI

אK


- ٥١ -

٦E אא ،אאא+V/2،

• אאא0V • אאאEFא

אא Kאאאא •

٢ J٢ J٢אא

١E אא(Non Return to Zero Level: NRZ-L) • ١WאFHIGHEאא • ٠WאFLOWEאא

W J J אאאא

א J א

אאאאאK

٢E אא(Non Return to Zero Mark: NRZ-M)Fאאdifferential Coding E

• ١Wאאא J ،אא

J ،אא

• ٠Wאאאאא

K


- ٥٢ -

W J J אאאא

٣E אאא(Non Return to Zero Space: NRZ-S)

• ١Wאאאאא

• 0Wאאא J ،אא

J ،אא

W J J אאאאK

٤E אאאאW(Unipolar Return to Zero: UPRZ)

• ١Wאאא J אאאא

J אאא

J אא

• ٠Wאאא

W J אא J NRZK


- ٥٣ -

٥E אאאאW

(Bipolar Return to Zero: BPRZ) (Polar Return to Zero: BPRZ)

• ١Wאאא J אאאא0V J אאא0V

• ٠Wאאא J אאא0אV J אאא0V

• אאאא،אאאאF+V0V -VE

• אא Wאא

WאאאK ٦E אאאאW (Return to Zero-Alternate Mark Inversion: RZ-AMI)

• ١Wאאא J אאא0אV J אאא0V J אא

• ٠WאFLOWEאא W

אאא٠אאאאא٠אאאאK


- ٥٤ -

W J אאאאK

W J J NRZK

٧E אאאW

Biphase- Level (BI Φ –L) or Manchester II code

• ١Wאאא J אאא J אאא

• ٠Wאא • אא

W J J NRZK

W J אאאK

٨E אאאW

Biphase- Mark (BI Φ –M) or Manchester I code

• ١Wאאא J אאא J אאא

• ٠Wאא


- ٥٥ -

W J J NRZK

W J אאאK

٩E אאאאW

Biphase- Space (BI Φ –S) code • ١Wאא • ٠Wאאא

J אאאא J אאא

• אא W

J א J NRZK

W J אאאK

١٠E אW

Delay modulation (DM) or miller code • ١Wא • ٠Wא٠،א

אאאא W

J אא W

J אאאK J NRZK


- ٥٦ -

אא

אא DC א

+V/2 fb/2 UPNRZ

O fP/2 BPNRZ

+V/4 fb UPPZ

א O V fb BPRZ

O V fb/2 BPRZ-AMI

٢א J٧Wאאא


- ٥٧ -

١E NRZ – L١١ ٠٠

٢E NRZ –M١אא

٠אא

٣E NRZ –S١אא ٠אא

٤E URZ –١١٠

٠٠

٥E PRZBPRZ١١٠ ٠١٠ J

٦E BRZ – AMI١

١٠א א١٠א J

٠٠ ٧E BIΦ-L١١٠

٠٠١

٨E BIΦ – M١١٠٠١ ٠אא

٩E BIΦ – S١אא

٠١٠٠١


- ٥٨ -

١٠E DM١אא ٠אאא

אאאK

٢א J٨א


- ٥٩ -

٢–٣אאאPCM/TDM

אאאW אFאEאKFE

K

٢ J٣ J١אאא ١Eאאא

אאFPAM/TDMKE ٢EאWK

• אfNK • Fs = fn = 2 fm • אאא • אאאאFאאא

אE

٣E٢א J٩א • אFframe timeE

E F٢ J٢١

٢א J٩Wאאא

Tf = TN = 1

2 fm


- ٦٠ -

Tω= Tf = 1

K 2K fm

• אFword timeE

F٢ J٢١E

• אFbit durationE

F٢ J٢٢E ٤E אאW

אאאאعرض نطاق : الحظ

אאK

٢ J٣ J٢אא א،אאאא

٢٤FUS – 24 Channel SystemEאא٣٢K

٢ J٣ J٢ J١٢٤FאWEFUS – 24 Channel SystemE ١Eא٢٤FCode WordsKEאא

אאאאאאא • אא124K • אF٠EאאאאF١٢٤E

אאK

Tω 1τ = =

N 2K N fm


- ٦١ -

א

٢٤٢٣٢٢٢١٢٠KKKKKKKKK١٣١٢١١١٠٩٨٧٦٥٤٣٢١1٠ ٢٤אאאFE٨אF١

E Z١٩٣אW٢٤х٨Z١٩٢H١א

• אאאא24א٠אK

• א8000

1µs١٢٥

٠Kאאאאאאאא •אאאFFrame Alignment Word: FAWKE

• א٢٤אאא،١٢אאאTI FAW

١٠٠٠١١٠١١١٠٠ • ١٢FEאFSuperframeE

א٢٤W

١K אFTI MultiplexerEא٢٤PCMאF٨EאFµs١٢٥E

٢K אאאאאא ٣K אאאKא

،Wא٨אא٨אא٨אאאא،א٢٤K

٤K אאאאאאאאאא KKKKאאאאא

٥K א١٢אאאאTI FAWK


- ٦٢ -

א٢٤W א٢٤אKאא

١٩٢KאאEFאאא١٩٣Kאא٨٠٠٠א،

٨٠٠٠x١٩٣א١٥٤٤٠٠٠אK

٢א J١٠W٢٤

אא٣٢W

FאZאBandwidth = Bit rate E • אfs=8kHz א125µs • אאאא١H٢٤C٨Z١٩٣ • אאא

ssTb µµ 647668.0193

125≈=

• א

sMbitsTb

Rb /544.1125

1931===

µ


- ٦٣ -

• ٥٤٤}١אאאא

MHzTB

BT 544.1

64766.011

===

٢א J١١Wאאאאא٢٤

٢ J٣ J٢ J٢٣٢FאאWEF32 Channel SystemE ١Eא٣٢ FCode WordsEאא

אאK • אא٠31K • אאF٠EאF١٦Eאאא

אאF١١٥١٧٣١EאאK

א ٣١٣٠٢٩KKKKKKKKK ١٧١٦ ١٥١٤١٣KKKKKKKKK٤٣٢١1٠ ١٥אאא

FE٨

א

١٥אאאFE٨

א

אW٢٤х٨Z١٩٢H١אZ١٩٣ • אאאא٣٠א٠١٦אK

• א8000

1µs١٢٥

• אאאאאאאאFSynchronization

and signalingEאא٠א١٦K


- ٦٤ -

א٣٢W ١K אא٣٠PCMאF٨

EאFµs١٢٥E ٢K אאאאאא ٣K אאאKא،

Wאאא٨אא٨אא٨אאאא،א١٥אאKא

אאאאKאאאאא٨א١٦٨א١٧٨א١٨א،

אא٣١א٣٢K ٤K אאאאאאאאאאאא

KKKKאא

אא٢٤W FאZאBandwidth = Bit rate E

• אfs=8kHz א125µs ٣٢C٨Z٢٥٦אאאא •• אאא

ssTb µµ 488.0256

125≈=

• א

sMbitsTb

Rb /2125

2561===

µ

• ٥٤٤}١אאאא

MHzTB

BT 2

488.011

===


- ٦٥ -

א٣٢W

א٢ J١٢Wא٣٢אאא

אאאאאא٣٢

٢א J١٣Wאאאאא٣٢

א٢ J١٣א٣٠L٣٢אאאאK


- ٦٦ -

٢–٤ FDelta Modulation: DME

Wאאא،אאאאאאK

• ١אאא٠אאאK • אLאאLאK

٢ J٤ J١אFLinear Delta Modulation: DME

א אאאא

٢א J١٤Wא

١EאאאFdifferential circuitEאאאאx(t) אא

z(t)א e(t) K

٢EאFsignal quantizerEאQ(t)אאאe(t) אאe(t) K

e(t) = x(t) – z(t)


- ٦٧ -

٣Eאאאe(t)F+1Eא e(t)F+1Eא e(t)K

٤Eאאא ∆Fstep sizeKE

٢אאאאא J١٥

٢א J١٥Wאאא

W

،אא،אאאK W

• W J א∆Fstep sizeE J אfs


- ٦٨ -

• אW J אFslope overloadE J אאFgranular noiseEאאK

אא\אFsignal to noise ratio S/NEא∆K

٢א J١٦WאFslope overloadE

٢א J١٧WאאFgranular noiseE

٢א J١٨WאLאFS/NEא∆


- ٦٩ -

٢ J٤ J٢אFadaptive delta modulationE ١E א،אא،

،אאא ٢E אאאא ٣E אאאא

،אאאאאאFstair case functionE ٤E ،אאאW

J ،אאאאאKאא

J אאאאאאאKאאK

٢ J٤ J٢ J٣

١E אאW • אאאFintegratorE • א،אאא • אאאFvariable gain amplifierKE

אאאאאאK

٢E אאW • אאאאא

J אFSong algorithmE אאאאאא∆אא

אא∆אאKאאאאK


- ٧٠ -

٢א J١٩WאFSong algorithmE

Fdamped oscillationEאא

J אאאFSpace shuttle algorithmE

אאאאאאאKא،אאאאK،א

אKאאאאK

٢א J٢٠WאאFSpace shuttle algorithmE

אאאא

אאאא


אאאא

א

א

٣


- ٧١ -

אאWאא

Band Pass Modulation (BPM)

אאWאאאאאFאאEאאFאאKE

אWאא،א، אאW

Jאא)Amplitude shift keying()ASK( Jאא)Frequency shift keying()FSK( Jאא)Phase Shift keying()PSK(

אאWאאא٩٠K٪

אאW١٥

אאWאא

אאWאאאאאאאאאאK


- ٧٢ -

1-3אא)bit rate(א)Baud rate(

אאאאא)ASK,FSK,PSK(אFKE

١ Jאא)Binary modulation(W

)bit(אאאאא W

Rb = Rs N2M=

(1-3) =122N = logM = log W

RbWאאFאאאאאאאאbit /secE

RsWאאאFאאאאאאאWאאאאKE

MWאאאK NWאאFאאאאאE ٢ Jאא)Quadrature modulation(W

אאאFאאאEW Rs = Rb/2

(2-3) = 4 22= N2M= N= log2 M = log 4 = 2


- ٧٣ -

٣ JאאאFאWE )N(אאאאFאEW

Rs = Rb/N = Rb/log2 M N2M =

N = log 2 M (3-3)

2-3אא)ASK(W

אאא)Ac sin wct(א)Ac cos wst(אאאאF٠EאאאאאF١EאאאW

Wאא

)ASKEאאאFאאאאאאאאא)AM.DSBTC()1-3(

1 1 +V 0 000

t -V

F1-3Eאאאא

١Eאא Vm(t)א)NRZ-L(א אא

Vc (t)= Ac cos 2π fct ٢Eאאאאא)ASK(W

= [A±Vm(t)] cos 2π fct VASK(t) = [Ft±v] Cos 2π fct

= A[1±V/A] Cos 2π fct = A[1±m] cost 2π fct

אא)ASK( VASK(t) = A [1±m] cos 2πfct (4-3 ) .

W)m(א


- ٧٤ -

אא)2-3(

אF2-3EFASKE

אא )ASK( ) Efficiency(

אm = 1 אאאFV٠2AE

)ASK(FASK(

אאאאאאא3-3(א(

F3-3EASK)(


- ٧٥ -

FASKEFASKE א)Envelope detector(

Wאא אאאאא)DSB-SC(אא

אאא)OOK( ) ON-OFF KEYING( אאאאW

١EאאאFunipolarE)modulating signal(

Vm (t) ={ +1 V logic 1

or { 0V logic 0

٢EOOK אאאאא א)5-3(

)(5-3 Vook(t) =Vm (t) *Vc (t) =Vm * Ac cos wct = { Ac*cos wct for logic (1)

for logic (0) ٠{

אאא)4-3(


- ٧٦ -

)(4-3 )OOK(

)OOK(FOOK(

אאאאאאא )Balanced Modulators(FאאE

5-3(א(FOOKEאאא

F5-3FEאOOKE


- ٧٧ -

אא)OOK Detection( אW

١Eאאא)coherent detection( אא)synchronous detection(

אאא)reference carrier(אאאאאKאאאא

אאאאאאאאאאאאא

phase & frequency mismatch distortion)( אF6-3Eאאאאאאא

)AMDSB-SC(ي بواسطة الكشف التزامن)synchronous detection(

)6-3(FאאOOKE

٢Eאאא)Non Coherent Detection( אא)Asynchronous detection(

אאאאאאאאא )Envelope detector()7-3(

F7-3FEאאאאאאE


- ٧٨ -

אW ١EאאאאאFdiodeEא

אאאאFtime constant of chargeEאאFforward resistanceE

אFreverse biasedEאאאאאאאFREא

R*CZTאא א

٢Eאאאאאאאאאא

٣EאאאאאאאFbinary restoration)אאא)comparator(

אFOOKFEOOK BandwidthE

١EאאאVm(t)FpcmE אא)ones followed by zeros(

אTm = 2Tb fm = 1/Tm =1/2Tb = Rb/2

٢E)OOK(אא)Fc(אא)Vm(t)

אE אאאF8c-3EFFcE

אאאFFmEFFcE


- ٧٩ -

F8-3EאאאאFOOKE

אF8c-3EאאFFmEאFdata rateFERbEאW

Rb=1/Tb =1/(Tm/2) =2Fm

٤EאאאאFFcEאאאאא

אאאאאF(Bandwidth אF3-3WE

BT= Rb = 2Fm (6-3) 1-3W FNRZ-PCME200 Kbit/sec)(

אFASKEאא


- ٨٠ -

אאFWאאאאE Performance: ( bit error rate & symbol error rate )

١Eאאאאאאא)BER(אאא)Probability of bit error ()(PB

אאא)Probability of symbol error()PE( ٢EאאאFאא

אאאEאאאאאK

٣Eא)BER()SER(אאW Jאא)BASK,BFSK,BPSK(

)symbol(א)1 bit(אFאEאאK

WBER = SERPB = PE Jאא)QASK,QFSK,QPSK(

)2 bit(BER = 1/2 SERPB = 1/2 PE Jאא)µASK,µFSK,µPSK(

)N(א)N(אאאאאW

PB = PE / N = PE / log2M )M(:אאאFאאאאE

16-PSK) (M = 16 N= log2 16 = 4 WPB = PE/ 4 KKKKKKKא ٤Eאא)BER(אFאאאאא

K ٥EFאFאאאאא

K ٦E)BER(Eb / No) ()SER()Es / No(W

Eb,Es=א No=אאא)W/HZ(


- ٨١ -

אBASK)(א Performance of binary BASK)(

אאאאאאאאאאאאא

אאK אאאאאאא

א ١Eאאא : Coherent detection)(

) NC 4/ =1/2 erfc (NoEb 2/PB=PE= 1/2 erfc (7-3) ) NoTbA 8/2= 1/2 erfc(

)(Non Coherent detection:الكشف الال ترابطي ) ٢

)8/2( NoTbAe−= 1/2 )4/( NC

e−

1/2= )2/( NoEb

e−

PB = PE = 8-3) (

٢ / Eb = (E1+Eo)א)(bitFE

א9-3(א(א

)9-3((BASK)FOOK(

E1=C*Tb = A2 Tb/2

Kאאאא Eo = 0


- ٨٢ -

Kאאא :

Eb = E1+E2/2= C Tb /2 = A2*Tb/4

C1=C= A2/2 אאאאאאא

Co = 0 אאא

אאאFAE)A – Peak amplitude of the received carrier (v)( No = N/BT= N/Rb = KT (W/HZ)

אאא N= KT*BT (W)

אא JK) 1023−K =(1.38*

T= ( TA+TR)

אאא)K(

TA)(WאאFאאE TA: TR=T1+T2/a1 =T3/a1+a2+…………….

אFאאאE T1,T2,T3,……..

אאא G1,G2,G2,….

אאא C/N

אאא

אBASK)EאאFBEREW


- ٨٣ -

F10-3EFBERE

2-3W F10 Kbit/sEא)(OOK א 10MHZ)(

(2-) 10 אV) (אאאא 5*10(-5) W/HZ)(

אאא) BER (

3-3אא Frequency Shift Keying (FSK)

אאאאאאאFFsFEאאEאאFFmFEאEאאאאאFbase bandE

אFpolarKE W

F∆אאאאאאאאא אFFCE

FSKW

١EאאFFSKEאW )9-3( VFSK (t) = (Ac cos { 2 π (fc + VM(t)) ∆f ) t }

אVFSKF(FSK- : حيث - A אא)(Volts

Fc JאאFאאE)HZ( ∆f Jאאאאא)Vm (t)()HZ(


- ٨٤ -

Vm (t) Jאאאאא)١±( Logic (1) = +1 , Logic (0) = -1

٢Eא)9-3(אW (a) VFSK (t) = A cos [ 2 π (fc + ∆f) t ] = A cos 2 π fmt .

for a logic 1 , Vm (t) = +1 (3-10) (b) VFSK (t) = A cos [ 2 π (fc - ∆f) t ]= A cos 2 π fst

for a logic 0 , Vm (t) = -1 W

Eאא)Logic 0()Logic 1(אאאFאEW

אFLogic 1EFm=Fc+∆F

אאFLogic 0EFs = Fc-∆F Eאאאא )Fm &Fs(א)(Fcאאאאא )∆F±Fc(

) FSK: (

١ () FSKEאאאE) VCO (وأ

Voltage Controlled Oscillator) ( אא

) 12-3() VCO(

):VCO(مبدأ عمل جهاز الـ) ٢

אFVoltageEאאK אא،אFSK)(

٣Eא)1±Vm(t) =(،אFVCOEאFF,FsE


- ٨٥ -

) FSK:(

F13-3EFSK)E

W Tm Jאא)sec( Fm Jאאאא)Vm (t)()HZ( Rb JאFbitsEא)bit/sec() Rb= 2Fm(

Fm Jא)Mark Frequency( Fs JאאFSpace Frequency E

אFbitsFERbEאאFBaud rateEFFSKWE ١EFFSKEאאאאאאאK ٢EאאאאK ٣EאאW

א)bit rateE)Rb(Wאאא אאא)Baud rate or symbol rate(Wאאא

٤Eאא)9-3(אאא)Fm(אא)Fs(אאאאאאאK

Bit rate =Symbol rate (Baud rate) Rb (bit/sec) = Rs ( Symbol/sec) = Baud rate ( baud)


- ٨٦ -

אא)FSK(W)FSK Bandwidth(

١Eאאא)BT(FFSKEאא)FM(אא)3-11(

BT = 2 (∆f + fm) (11-3) (∆F =Fm-Fs/2) W

Fm = Rb/2 (Fc) אאאאאאא : WאאאאאאFEא

אאא א)١٢-٣( (11-3) א (Fm ∆F) ٢E

BT = 2 ∆ f + 2 fm = fm – fS + Rb (12-3)

)BT( אאא )FSK(

F14-3EאאFFSKE

אאא)Pulsed sinusoidal waves(אא)sin x/x(

)(FSKאא)12-3( אא)Fm(אא)Rb(W

Rb = 2Fm


- ٨٧ -

אאאאאאאאאא)14-3(

אאאK

3-3:

FPCMEאFNRZ-LEאאF200 K bit / secEFFSK(،אאאאאא)150KHZ(K

א

אW ١ Jאאאאאא )Fm( א)Fs(K ٢ Jאאא)Logic 1(אאאא

אאאאאא)Logic 0(

٣ Jאאאאא)Pulsed RF Signal(אאא)base band(

٤ JאאאאאK ٥ Jאאא

אאאא)Binary restoration(אK


- ٨٨ -

EאאאFSK)(W FSK Coherent detection

F15-3EאאאFFSKE

אW ١K אאאאאאא

אאאאאאא

אאאאאאאK JאאאאFLogic 1EאאאW

13-3)( Vr(t) = Acos wm(t) JאאאאW 14-3)( Vc(t) = 2A cos(2) wmt = A( 1+ cos 2wmt)

٢K אאאא14-3)Eאאאאאאאא)differential amp.(

אאאאאא)15-3: (

15-3)( Vo (t) = Gv Vd(t) = A*Gv = positive constant אאאאאFLogic 1E ٣K אאאאאFLogic 0Eא

אאK


- ٨٩ -

אא)Performance(W WאאאEא

BER = PB = ½ erfc ⎟⎟⎠

⎞⎜⎜⎝

⎛

NoEb

2

= ½ erfc ⎟⎟⎠

⎞⎜⎜⎝

⎛

NoPcTb2

= ½ erfc ⎟⎟⎠

⎞⎜⎜⎝

⎛

NoTbA

4

2

Eb = PC Tb

PC =

No =

W F(Ebא FPcEאא FNoEאאא

Eאאא

BER = PB = ½ exp ( ) (3-17)

= ½ erfc ⎟⎟⎠

⎞⎜⎜⎝

⎛NoTbA

2

2

אאאאאא

אאא)bits(אאא F16-3Eאא)PB(אאא

א

(3-16)

A2 2 PN BT

-Eb 2NO


- ٩٠ -

) =F(C/N) ( F PB =

) 16-3 (אא)FSK(

4-3:

)( BERאWאאאאאאא)FSK( א)bit()2sec(א)0.4 V(אאא):1KHZ,2KHZ(

אאא)10(-12) w/HZ( אא13-3(א(א)BER(

4-3אא

Phase Shift Keying (PSK)

אאאאאFאאאאEאאאW

Jא)ASK( K Jאא)FSK(K

-Eb 2NO


- ٩١ -

אאאאW ١EPSKאאאאאא)Binary PSK(

אאE ٢E PSKאאאאאאאQuadrature PSK)(

אאKE ٣EPSKא) PSKא( )µ-PSK( FאאFMEאאFאאEא

אאאK W

)18-3(

W

Nb JאFE M JאאFאאאE

5-3W FPSKE M= 2KאאאאK אאא) Binary PSK(

)17-3(אאא )BPSK(


- ٩٢ -

١ JאאאU (t))PCM(אF°٩٠א°-90KE

٢ Jאא )(Uiא)i(אאFאאEאW

(19-3 )

W V Jא)volts(

Ui Jאא Ui ={+1 for logic (1)

{-1 for logic (0)

א)19-3 (W Jlogic (1)אF2/ πE-

Jlogic (0)אF2/ πHE ٣ Jאאאא(19-3)אW

F20-3E


- ٩٣ -

אFBPSKWE ١E א)BPSK(א

אאF١٠E

)18-3(א )BPSK(

:الحامل هو ) ٢Vc (t)=Vsin wct

) 19-3 (א) (BPSK


- ٩٤ -

٣( V BPSK(t):

א

VBPSK(t)

BW=2fm=Rb t

f fc+fm fm-fc

F20-3EאאFVBPSKE

٤EאאאאאאFE W

fctπFmt*sin2πV BPSK(t) = sin 2

] (fc+fm)t π (fc-fm)- 1/2 cos2π cos 2[= 1/2

אאW B= (fc+fm) – (fc+fm)=2fm=Rb

אWBT = Rb FאאאאE

אאאW B= 2(∆f+fm)=2fm+2∆f

W 2∆f=0 אאW

B= 2fm = Rb


- ٩٥ -

אא)BPSK(

EBPSK)EW

אאF21-3Eאא)OOK(אא)OOK(אK

Bw=Rs

Ui V sinωct Ui V sin wct Binary ui= VBPSK(t)

data VSinωct

)21-3()BPSK(

E)BPSK(W אאא)Ui(אאא

אאאאאאאאא)balanced modulator( אא

אאאאK

Balanced Modultor BPF

Reference Carrier

oscillator


- ٩٦ -

Vd(t)=2uiVsinwct Logic 1+v{ Vo=VUi=

input signal Vo=V {-v logic 0 VBPSK(t)= VUisinωct 2 sinωct

F22-3E)BPSK( J אאאW J אאאW

אאאאאאא)LPF(אאW

- אאאאאא

אאאאאK

Carrier oscillator

Balanced detector

L P F


- ٩٧ -

אא )Performance(:

PB = PE = 1/2 erfc ( NOEB / )

= 1/2 erfc ( NoTbc /* ) (21-3)

= 1/2 erfc ( NoTbv 2/2 )

• אאאא PB) Eb/No((BER) • )22-3(

F23-3E


- ٩٨ -

אאא)QPSK(: Quadrature phase shift keying

١E)QPSK(אאא

אאK

٢E) QPSK () BPSK (אא:

(٢٢-3)

W Jאאא)BPSK(אא)I( Jאאא)BPSK(א)Q( Jאא)V QPSK(אאאW

UQV 2VQPSK=V

UIV

VQPSK = UiVcosωct + UQVsinωct

│VQPSK │= (UiV)2 + (UQV)2 = 2 v 2 = V 2 (23-3)


- ٩٩ -

٣Eא)46-3(א)47-3(W

= cosΦcoswet + sinΦsinwet = cos(ωct-Φ )

אW

:ن إحيث

אאא - Φ

24-3)(

(π / 4 , 3π / 4 , 5π / 4 , 7π / 4) אא Φ אא)1-3 (אאאאא)UI,UQ(

אאאFΦE)QPSK(אK VQPSK (eq. 72)

VQPSK (eq. 74) Phasor t

s

UI UQ Vcosωct+vsinωct v 2 cos(ωct- π /4)

Φ=45

1 1

-vcosωct+vsinωct v 2 cos(ωct-3 π /4)

Φ=135

-1 1

-vcosωct-vsinωct v 2 cos(ωct-5 π /4) Φ=225

-1 -1

-vcosωct-vsinωct v 2 cos(ωct-7 π /4) Φ=315

1 -1

F1-3E

VQPSK = V 2cos(ωct – Φ)

Φ = tan-1 UQ UI

Transmitted bite


- ١٠٠ -

אאW Eא)Rs()PSK(אאW

symbols/s NRRs b=

W Rb Jאא N Jא Eאאאא

M = 2N symbols

Eאאאא

radM2 π

M360P ==

Eאאא

C = B log2 M W

B Jאא

אאא)S/N(W )א)PCM(( ١EאאאאאאW Eאא)BER(W

אאאאאא)Thermal noise(אאאK

Eאא)S/N(W )PCM(


- ١٠١ -

W JאאאWא)BER( Jא)Quantization noise(W

אW

(S/N)Q = 22N = M2

W M JאK N JאאאK

٢Eאאאאאאא

ASK,FSK,PSK

NoEb

אאא)PCM(אאאW

RF mixer IF detector D/A *(S/N)

V

*PCM

PB * LPF

(S/N)or


- ١٠٢ -

6-3:

אאאאא200fw (200x10-15W). אאא)300K(אא

)425K(K

אאא)PCM(FbitE2Mbit/sec)(אW

Eא)PSK( Eא)ASK( Eאאא)ASK(

E آشف ترابطي )QPSK(

א אא א ٢٣٧ אא

- ١٠٣ -

אא

1. Ashok Ambardar, ‘Analog and Digital Signal Processing’, Thomson Learning Inc, 1999. 2. John B. Anderson, ‘Digital Transmission Engineering’, Prentice Hall, 1999. 3. A.B.Carlson, ‘Communication Systems’ McGraw-Hill, 1992. 4. Simon Haykin: ‘Communication Systems’, 4th Edition, Wiley & Sons, 2001. 5. Simon Haykin and Barry Van Veen: ‘Signals and Systems’, John Willey & Sons, Inc, 1999. 6. Simon Haykins, ‘Digital Communication’, John Wiley, 2001. 7. B.P.Lathi, ‘Analog and Digital Communication Systems’, PHI, 1992. 8. Douglas K. Lindner, ‘Signals and Systems’, McGraw-Hill International, 1999. 9. John Pearson : ‘Basic Communication Theory’, Prentice Hall, 2000 10. J. Proakis: ‘Digital Communications’, McGraw Hill, 1995. 11. J. Proakis and M. Salehi: ‘Contemporary Communication Systems Using

MATLAB’, Bookware Companion Series, PWS Publishing, 1998. 12. Proakis, ‘Digital Communication’, McGraw-Hill, 1992. 13. Martin Roben: ‘Analog and Digital Communication Systems’, 4th Edition, Prentice Hall, 1998 14. K.Sam Shanmugam: ‘Digital and Analog Communication Systems’, John Wiley, 1985. 15. Bernard Sklar: ‘Digital Communications, Fundamentals and Applications’, Second Edition,

Prentice Hall, 2001. 16. Taub & Schilling: ‘Principles of Communication’, McGraw-Hill Publication, 1990. 17. Wayne Tomasi: ‘Advanced Electronic Communication Systems’, Prentice Hall, 2001 18. Rodger E. Ziemer and Roger L. Peterson: ‘Introduction to Digital Communication’,

2nd Edition, Prentice-Hall, 2001. 19. Roger E. Zeimer et al.: ‘Signals and Systems, Continuous and Discrete’, McMillan, 2nd Edition,

1990.

א אא א ٢٣٧ א

- ١٠٤ -

א

............................................................................................................ ............................................................................................................

אאWא....................................................................................١ ١ J١אW..................................................................................٢ ١ J٢אFAliasingE...................................................................................٥

١ J٣WאFTypes of samplingE.............................................................٦

١ J٤אא..............................................................١١

١ J٥אאאאאאא..................................١٤ ١ J٦א٢٤........................................................................א

١ J٧אאאא.....................٣٠

אאWא٣٢.............................................................................א ٢–١אאא.......................................................................٣٣ ٢–٢א.........................................................................................٤٩ ٢–٣אאאPCM/TDM.....................................٥٩ ٢–٤.........................................................................................٦٦

אאWאא.........................................................................٧١ 1-3אא)bit rate(א)Baud rate(.......................................٧٢ 2-3אא)ASK(W.................................................................٧٣

3-3אא...........................................................................٨٣ 4-3אא...........................................................................٩٠

א١٠٣.....................................................................................................א

אאאאאא אאFאEא

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