Digital Transmission in Digital Communications

‫א‬‫א‬

‫א‬‫א‬‫א‬

‫א‬‫א‬‫א‬

٧

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬


 
 

 K‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬W‫א‬‫א‬
 
 W‫א‬‫א‬‫א‬‫א‬W‫א‬‫א‬
 
 K‫א‬‫א‬‫א‬ J
 

 K‫א‬‫א‬‫א‬ J
 K‫א‬‫א‬  J







 


 

 K٦W‫א‬‫א‬

 
 

W‫א‬‫א‬

  J١

 ‫א‬‫א‬‫א‬‫א‬ J٢
 ‫א‬‫א‬ J٣
 

 W‫א‬‫א‬

 ‫א‬‫א‬

-١٠٨-

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬


 

 



 Digital Transmission ‫א‬‫א‬‫א‬ J٧
 
 ١ J٧
 
F ‫א‬ ‫א‬‫א‬  ،   ‫א‬   ‫א‬ ‫א‬‫א‬ 

،‫א‬،‫א‬ ‫א‬،‫א‬ F ‫א‬   ‫א‬ E‫א‬ ‫א‬ ‫א‬

 W‫א‬‫א‬‫א‬‫א‬KELAN‫א‬‫א‬

 ‫א‬‫א‬‫א‬‫א‬‫א‬،‫א‬ J

 

‫א‬EAM, FM and PM‫א‬F‫א‬‫א‬‫א‬
 K‫א‬

 ‫א‬‫א‬E‫א‬F‫א‬ J
 ،‫א‬‫א‬‫א‬،K‫א‬‫א‬



 KEASK, FSK, PSK,…‫א‬F‫א‬‫א‬‫א‬‫א‬
‫א‬‫א‬‫א‬FE‫א‬‫א‬FESymbolF‫א‬
 K‫א‬‫א‬‫א‬EQAM, QPSK, …F‫א‬

 KEPhaseFEAmplitudeFEM-ary

 EEncodingF‫א‬‫א‬ J

 KEDSL،‫א‬‫א‬‫א‬F‫א‬

 ‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬ J



 K‫א‬‫א‬EPCMF
 

 K‫א‬‫א‬‫א‬‫א‬١ J٧‫א‬
 

-١٠٩-

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬



 
‫א‬‫א‬‫א‬ ١٩٧٠‫א‬‫א‬‫א‬
‫א‬‫א‬‫א‬‫א‬‫א‬

 K‫א‬‫א‬‫א‬E‫א‬‫א‬F‫א‬‫א‬‫א‬
‫ﻧﻈﺎم اﺗﺼﺎﻻت ﺗﻤﺎﺛﻠﻲ‬
Analog
Signal

Modulator
AM, FM, PM

Channel

Receiver
Demodulator

--‫أ‬‫ﻧﻈﺎم اﺗﺼﺎﻻت رﻗﻤﻲ‬
Discrete
Signal

Dig. Mod.
ASK, FSK,
PSK

Channel

Receiver
Demodulator

--‫ب‬‫اﻹرﺳﺎل اﻟﺮﻗﻤﻲ ﻟﻺﺷﺎرات اﻟﺘﻤﺎﺛﻠﻴﺔ‬
Analog
Signal

 

Sampler
Quantizer
Encoder
PCM, DM

Digital
Comm.
System

Decoder
And
D/A
Converter

--‫ج‬ 

 J،‫א‬‫א‬ J،‫א‬‫א‬ J،‫א‬‫א‬١ J٧‫א‬
 ‫א‬‫א‬‫א‬‫א‬‫א‬
 

 W‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬
K‫א‬‫א‬‫א‬‫א‬‫א‬‫ א‬K١

K‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬‫ א‬K٢
-١١٠-

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬



 K‫א‬‫א‬E‫א‬‫א‬‫א‬‫א‬‫א‬F‫א‬‫א‬ K٣

 

 W‫א‬‫א‬‫א‬‫א‬‫א‬

KE‫א‬‫א‬F‫א‬‫א‬‫א‬ 

 

KE01‫א‬  F‫א‬ 
KEBERF‫א‬‫א‬‫א‬‫א‬‫א‬ 

    ‫א‬  E SNR F ‫א‬  ‫א‬  ‫א‬‫א‬  
KEBERF‫א‬

K‫א‬‫א‬‫א‬EBandwidthF‫א‬‫א‬‫א‬‫א‬ 

‫א‬ ‫א‬   E ‫א‬ F ‫א‬   E Encoding F ‫א‬  
KESignal ElementsF

 

Transmission Modes ‫ א‬ ٢ J٧
 

K‫א‬‫א‬‫א‬‫א‬،‫א‬‫א‬‫א‬

 K‫א‬‫א‬‫א‬‫א‬‫؛‬‫א‬، ‫א‬‫א‬‫א‬
 

  Serial Transmission ‫א‬‫א‬

١ J٢ J٧
 

،E TbF ‫א‬   ‫א‬  ‫א‬‫א‬
‫א‬  ‫א‬   E Least Significant Bit, LSB F  ‫א‬ ‫א‬  ‫א‬   

‫א‬ ‫א‬    KE٢ J٧ ‫א‬F ،‫א‬ E Most Significant Bit, MSBF  ‫א‬
‫א‬‫א‬K‫א‬‫א‬‫א‬‫א‬‫א‬

‫א‬،‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬

 K‫א‬‫א‬‫א‬‫א‬‫א‬

-١١١-

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬


 

 ‫א‬‫א‬E٢ J٧F‫א‬
 

Parallel Transmission ‫א‬‫א‬‫א‬٢ J٢ J٧
 

‫א‬K‫א‬‫א‬‫א‬،‫א‬‫א‬‫א‬

 W‫א‬‫א‬E٣ J٧‫א‬F‫א‬‫א‬
 ‫א‬‫א‬ J

‫א‬‫א‬EAttenuationF‫א‬ J
 

 

 

 ‫א‬‫א‬‫א‬E٣ J٧F‫א‬
-١١٢-

 



‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬


 
 

،‫א‬ ‫א‬ ‫א‬ ‫א‬  ‫א‬‫א‬ ‫א‬ ،‫א‬  ‫א‬ ‫א‬  

‫א‬‫א‬   E ٤ J٧ ‫א‬ F   ‫א‬    ‫א‬   
 KEShift RegistersF‫א‬‫א‬‫א‬‫א‬
 

 

 

   ‫א‬‫א‬E٤ J٧F‫א‬
 

 Asynchronous Transmission‫א‬‫א‬‫א‬٣ J٢ J٧
 

E StartF‫א‬‫א‬،E ٥ J٧‫א‬F‫א‬‫א‬‫א‬
‫א‬‫א‬KE BytesF‫א‬E Gap F‫א‬‫א‬،E StopF‫א‬

‫א‬‫א‬‫א‬،E‫א‬‫א‬F‫א‬
 

-١١٣-

 KEClock SignalF‫א‬
 

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬


 

 

 

 ‫א‬‫א‬‫א‬E٥ J٧F‫א‬
 

Synchronous Transmission ‫א‬‫א‬‫א‬٤ J٢ J٧
 

‫א‬‫א‬‫א‬‫א‬‫א‬،E٦ J٧‫א‬F‫א‬‫א‬‫א‬
‫א‬   ‫א‬  KE Gaps F ‫א‬   E Stop F ‫א‬  E Start F ‫א‬‫א‬
‫א‬E Clock SignalF‫א‬‫א‬‫א‬‫א‬،‫א‬

 K‫א‬‫א‬‫א‬
 

 

 

 ‫א‬‫א‬‫א‬E٦ J٧F‫א‬
 

 Line Coding ‫א‬٣ J٧
 

 ‫א‬‫א‬EDigital DataF‫א‬‫א‬‫א‬‫א‬
-١١٤-

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬



 
F‫א‬E Digital WaveformsF‫א‬E BasebandF

 KE‫א‬
 

 Line Coding Parameters ‫א‬١ J٣ J٧

 

 W‫א‬‫א‬‫א‬‫א‬‫א‬
WESignal SpectrumF‫א‬‫ א‬
 K‫א‬‫א‬‫א‬‫א‬ J

 ‫א‬‫א‬‫א‬EdcF‫א‬ J

 K‫א‬‫א‬‫א‬‫א‬‫א‬EAc couplingF
 K‫א‬‫א‬‫א‬ J
 

   ‫א‬ ‫א‬     WE Synchronization F ‫א‬‫ א‬
 ‫א‬ ‫א‬     ،E Clock Frequency F ‫א‬‫א‬  

 ‫א‬‫א‬    ‫א‬‫א‬       ‫א‬
‫א‬‫א‬‫א‬،‫א‬EClock ExtractionF‫א‬‫א‬
K

‫א‬‫א‬‫א‬WE Error CorrectionF‫א‬ 
 K 

ESignal Interference and Noise ImmunityF‫א‬‫א‬‫א‬‫א‬‫א‬‫ א‬

  ‫א‬   ‫א‬‫א‬ ‫א‬   ‫א‬     
 K‫א‬‫א‬
 

-١١٥-

 

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬



‫א‬‫א‬‫א‬‫א‬‫א‬WETransparencyF‫ א‬

 

KE?0??1? ‫א‬F

‫א‬‫א‬WECost and ComplexityF‫א‬‫ א‬
K‫א‬

 

W‫א‬‫א‬‫א‬
 

K
 ‫א‬EClock RecoveryF‫א‬‫א‬ 

KEdcF‫א‬ 

K‫א‬‫א‬ 
K‫א‬‫א‬‫א‬‫ א‬

 Line Code Types‫א‬‫א‬٢ J٣ J٧
 

 W‫א‬‫א‬‫א‬

 W،EPulse DurationF‫א‬‫א‬W 
 ،NRZ‫א‬‫א‬ENon return-to-zeroF‫א‬‫א‬ J

 


 ETbF‫א‬‫א‬‫א‬EτF‫א‬‫א‬

 ‫א‬،RZ‫א‬‫א‬E Return-to-zeroF‫א‬‫א‬ J







Kτ = 0.5 Tb KETbF‫א‬‫א‬‫א‬EτF‫א‬
 W،EPulse Voltage LevelF‫א‬W 

 ?0?‫א‬ E+ A VoltsF?1?‫א‬،EUnipolarF‫א‬ J

 

KRZNRZK‫א‬

 ?0?‫א‬ E+ A VoltsF?1?‫א‬،EpolarF‫א‬ J
-١١٦-

 

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬

 



KRZNRZKE- A VoltsF

 

 ?1?‫א‬،EDipolarF‫א‬ J

 dc‫א‬‫א‬‫א‬K?0?‫א‬

 KEManchester CodeF‫א‬‫א‬K‫א‬

 E+ A VoltsF?1?‫א‬،EBipolarF‫א‬ J

E Alternate Mark InversionF‫א‬‫א‬K?0?‫א‬ 
 KEAMIF‫א‬‫א‬
 

 Unipolar Coding‫א‬١ J٢ J٣ J٧
 

 K‫א‬‫א‬‫א‬‫א‬‫؛‬‫א‬‫א‬
 WENRZF‫א‬‫א‬‫א‬

 W‫א‬

 K‫א‬‫א‬ J

 K‫א‬ J




 W‫א‬

  Kdc J



 K‫א‬ J



 KEAc couplingF‫א‬‫א‬ J

 K‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬ J





 

 K‫א‬‫א‬‫א‬‫א‬E٧ J٧F‫א‬
 

-١١٧-

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬


 

1

0

1

0

1

1

1

1

1

0

A
Tb = τ

 

0

 ENRZF‫א‬‫א‬،‫א‬‫א‬E٧ J٧F‫א‬

 WERZF‫א‬‫א‬‫א‬
 

 W‫א‬

 K‫א‬‫א‬ J

 K‫א‬‫א‬‫א‬  J




 

 W‫א‬

 Kdc J



 K‫א‬ J



 KEAc couplingF‫א‬‫א‬ J
 K‫א‬‫א‬‫א‬EBandwidthF‫א‬‫א‬‫א‬ J




 K‫א‬‫א‬،‫א‬‫א‬E٨ J٧F‫א‬
 

0

1

0

1

1

1

0

0

0

Tb

 

+
3
A
0

τ

 

 ERZF‫א‬‫א‬،‫א‬‫א‬E٨ J٧F‫א‬
 
 
-١١٨-

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬


 
 ١ J٧

 

 KRZNRZ‫א‬‫א‬‫א‬‫א‬
 

 1 1 0 1 1 1 0 0 0 1

 
 
 W‫א‬
 

1

1

0

1

1

1

0

0

0

1

Unipolar
NRZ

Unipolar
RZ

 

 ١ J٧E٩ J٧F‫א‬
 

 Polar Coding‫א‬‫א‬٢ J٢ J٣ J٧
 
 WENRZF‫א‬‫א‬‫א‬
 

 W‫א‬

 K‫א‬‫א‬ J
-١١٩-



‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬



 Kdc J

 


 KEAc couplingF‫א‬‫א‬ J



 K‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬ J



 



W‫א‬

 K‫א‬ J



 KEBandwidthF‫א‬‫א‬‫א‬ J



 

 ‫א‬‫א‬،‫א‬‫א‬E١٠ J٧F‫א‬
1

0

1

0

1

1

1

1

1

0

+A
Time

0

  -A

 

 ‫א‬‫א‬،‫א‬‫א‬E١٠ J٧F‫א‬

 

 WERZF‫א‬‫א‬‫א‬

 W‫א‬

 K‫א‬‫א‬ J
 Kdc J




 W‫א‬

 K‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬ J



 K‫א‬ J



 KEAc couplingF‫א‬‫א‬ J
 K‫א‬‫א‬‫א‬EBandwidthF‫א‬‫א‬‫א‬ J
-١٢٠-




 

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬



 
 K‫א‬‫א‬،‫א‬‫א‬E١١ J٧F‫א‬
 

1
1

0
0

1
1

0
0

1
1

1
1

0
1

0
0

1
0

0
0

+A
0

  -A

 ‫א‬‫א‬،‫א‬‫א‬E١١ J٧F‫א‬
 ٢ J٧

 

 K±3V‫א‬RZNRZ‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬
 

1 0 1 0 1 1 0 0 1 0

 
 W‫א‬
 

+3
Time

0
-3
NRZ

‫ﻏﻴﺮ اﻟﺮاﺟﻊ ﻟﻠﺼﻔﺮ‬

-١٢١-

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬


 

1

0

1

0

1

1

0

0

1

0

0
-3
RZ

‫اﻟﺮاﺟﻊ ﻟﻠﺼﻔﺮ‬
 

 ٢ J٧E١٢ J٧F‫א‬
 
 
 
 Bipolar‫א‬٣ J٢ J٣ J٧
 

 ? 1 ? ‫א‬   ‫א‬  ، ‫א‬‫א‬  ‫א‬‫א‬ ،‫א‬ ‫א‬   
 

 K‫א‬?0?‫א‬،


 WENRZF‫א‬‫א‬‫א‬
 

 W‫א‬

 K‫א‬‫א‬‫א‬ J



 Kdc J



 KEAc CouplingF‫א‬‫א‬‫א‬ J



 KE‫א‬F‫א‬‫א‬ J



 
 

-١٢٢-

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬

 




 
W‫א‬

 K‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬ J



 KE‫א‬?0?‫א‬F‫א‬ J



 

 K‫א‬‫א‬،‫א‬‫א‬E١٣ J٧F‫א‬
 

1

0

1

0

1

1

1

1

1

0

+V
0

  -V

 

 ‫א‬‫א‬،‫א‬‫א‬E١٣ J٧F‫א‬

  ERZF‫א‬‫א‬‫א‬
 

 W‫א‬

 K‫א‬‫א‬‫א‬ J



 Kdc J



 KEAc CouplingF‫א‬‫א‬‫א‬ J



 KE‫א‬F‫א‬‫א‬ J

 ‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬ J
 KERectifierF
 






W‫א‬

 KE‫א‬?0?‫א‬F‫א‬

 





K‫א‬‫א‬،‫א‬‫א‬E١٤ J٧F‫א‬
 

-١٢٣-



‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬


 

1

0

1

0

1

1

1

1

1

0

+A
0
-A

 

 ‫א‬‫א‬،‫א‬‫א‬ E١٤ J٧F‫א‬
 
 
 Manchester Coding٤ J٢ J٣ J٧
 

?0?‫א‬?1?‫א‬، 

 KE١٥ J٧‫א‬F
 

 W‫א‬

 Kdc J



 K‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬ J



 KEAc CouplingF‫א‬‫א‬‫א‬ J
 K‫א‬ J





 

 W‫א‬

 K‫א‬‫א‬ J
 K‫א‬ J





 

 KE١٥ J٧F‫א‬
-١٢٤-

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬


 

1

0

1

0

1

1

1

1

1

0

+A
0
-A

 

Tb ‫داﺋﻤ ًﺎ هﻨﺎﻟﻚ اﻧﺘﻘﺎل ﻣﻦ اﻟﻤﻮﺟﺐ ﻟﻠﺴﺎﻟﺐ وﺑﺎﻟﻌﻜﺲ ﻋﻨﺪ ﻣﻨﺘﺼﻒ اﻟﻔﺘﺮة اﻟﺒﺖ‬

 E١٥ J٧F‫א‬
 
 ٣ J٧

 K±3V‫א‬RZNRZ‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬
 1 1 0 1 1 1 0 0 0 1

-١٢٥-

 



‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬


 
W‫א‬

1

1

0

1

1

1

Unipolar
RZ

Bipolar
RZ

RZ-AMI

 

 

 ٣ J٧E١٦ J٧F‫א‬

-١٢٦-

0

0

0

1

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬


 

 
 
K‫א‬ K١

K‫א‬ K٢

‫؟‬‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬ K٣

‫؟‬‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬ K٤

‫؟‬‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬ K٥
‫؟‬‫א‬‫א‬‫א‬‫א‬‫א‬ K٦

K‫א‬‫א‬،‫א‬‫א‬‫א‬‫א‬‫א‬ K٧
K‫א‬‫א‬‫א‬‫א‬ K٨

K‫א‬‫א‬ K٩

‫א‬   ‫א‬  ‫א‬ ‫א‬‫א‬   ‫א‬  ‫א‬ ‫א‬   K١٠
K‫א‬

‫؟‬‫א‬‫א‬‫א‬ K١١

‫؟‬‫א‬‫א‬ K١٢

KRZNRZ‫א‬‫א‬‫א‬‫א‬ K١٣
 

1

0

0

0

1

Unipolar
NRZ

Unipolar
RZ

 

-١٢٧-

1

0

1

0

0

‫א‬‫א‬
 ‫א‬‫א‬‫א‬

 ٢٣١

 ‫א‬

 ‫א‬‫א‬

 ‫א‬



‫א‬     RZ  NRZ ‫א‬ ‫א‬ ‫א‬ ‫א‬ ‫א‬ ‫א‬   K١٤

K±5V

1

1

1

0

0

1

0

0

1

NRZ

0

RZ

0

 

 

 

KRZNRZ‫א‬‫א‬‫א‬‫א‬‫א‬‫א‬ K١٥


1

0

0

1

1

Unipolar
RZ

Bipolar
RZ

-١٢٨-

1

0

1

0

1

 