30820-Communication Systems
Week 1 – Lecture 1-3
(Ref: Chapter 1 of text book)
INTRODUCTION
Course Information
•
Instructor: Dr. Adnan Zafar (Assistant Professor)
•
Text Book: “Modern Digital and Analog Communication Systems”, 4th Edition,
By B. P. Lathi, Zhi Ding
Program Learning Outcome: The course is designed so that students will
achieve
•
•
– Office: Room 15, EE Department, Block VI
– Email: adnan.zafar@ist.edu.pk
– Problem Analysis: PLO-02
– Design/Development of Solution: PLO-03
Course Learning Outcome: Upon successful completion of the course, the
students will be able to
– Apply the concepts of signals and systems to different communication systems
– Analyze different analog and digital transmission schemes
– Design amplitude modulation (AM) and frequency modulation (FM) transmitter
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Assessment
Quizzes (surprise, announced)
Assignments (week 5-7 & week 8-10)
OHT Exams (7 week & 13 Week)
Final Exam (Scheduled Week)
20%
10%
25%
45%
Total
100%
th
th
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Contents
• Communication Systems
• Analog and Digital Messages
• Channel Effect, Signal to Noise Ratio and Capacity
• Modulation and Detection
• Digital Source Coding and Error Correction Coding
• A Brief Historical Review of Modern Telecommunication
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What’s Communication?
• Communication involves the transfer of information from one point to
another.
• Three basic elements
– Transmitter: converts message into a form suitable for transmission
– Channel: the physical medium, introduces distortion, noise, interference
– Receiver: reconstruct a recognizable form of the message
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Analog Messages
• Early analog communication
– telephone (1876)
– phonograph (1877)
– film soundtrack (1923, Lee De Forest, Joseph Tykocinski-Tykociner)
• Key to analog communication is the amplifier (1908, Lee De Forest, triode
vacuum tube)
• Broadcast radio (AM, FM) is still analog
• Broadcast television was analog until 2009
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Digital Messages
• Early long-distance communication was digital
– semaphores, signal flags, smoke signals, bugle calls, telegraph
• Teletypewriters
– Baudot (1874) created 5-unit code for alphabet
– Today baud is a unit meaning one symbol per second
– Working teleprinters were in service by 1924 at 65 words per minute
• Fax machines: Group 3 (voice lines) and Group 4 (ISDN)
– First fax machine was invented by Alexander Bains in 1843
– Pantelegraph (Caselli, 1865) set up telefax between Paris and Lyon
• Ethernet, Internet
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