Intro to COMMS1_ppt1.1

Introduction to Electronic Communication Systems

  • Overview of course module highlighting key aspects of electronic communication.

  • Technological University of the Philippines - Manila as the educational context.

History of Electronic Communication

19th Century Innovations

  • 1837: Invention of Telegraph by Samuel Finley Breese Morse.

  • 1843: Invention of Facsimile by Alexander Bain.

  • 1864: Discovery of Electromagnetism by James Clerk Maxwell.

Later Developments

  • 1866: Installation of the first transatlantic cable.

  • 1876: Invention of Telephone by Alexander Graham Bell.

  • 1877: Invention of Phonograph by Thomas Alva Edison.

  • 1880: Discovery of Electromagnetic Waves by Heinrich Hertz.

  • 1887: Discovery of Radio Waves by Heinrich Hertz and demonstration of wireless radio propagation by Marconi.

20th Century Advances

  • 1906: Invention of Amplitude Modulation (AM) by Reginald Fessenden.

  • 1918: Invention of Superheterodyne Receiver by Edwin Armstrong.

  • 1934: Creation of the Federal Communications Commission (FCC).

  • 1937: Invention of Pulse Code Modulation (PCM) by Alec Reeves.

Components of Electronic Communication System

  • Transmitter: Device to send information.

  • Transmission Medium/Channel: Path for the signal, can introduce noise and impairment.

  • Receiver: Device to receive and interpret the signal.

  • System Noise and Interference: Factors affecting communication quality.

Transmission Modes

  • Simplex Mode: Unidirectional transmission; signal only sent in one direction.

  • Duplex Mode: Bidirectional transmission but not simultaneous; can send and receive, but not at the same time.

  • Full Duplex: Bidirectional transmission; can send and receive simultaneously.

  • Half Duplex: Bidirectional, but only one direction at a time; can switch directions.

Transmission Impairments

  • Signals may suffer from impairment during transmission; the original signal differs from the received signal.

  • Causes of impairment include insufficient media quality and environmental factors.

Electrical Noise

  • Defined as random, undesirable electrical energy unnecessarily injected into the communication system, impacting signal integrity.

General Classification of Noise

Correlated Noise

  • Present within the signal itself; relevant when there is an active signal.

  • Distinguished by presence alongside the signal.

Uncorrelated Noise

  • Exists independent of any signal; similarly observed during no signal conditions.

Types of Correlated Noise

Harmonic Distortion

  • Occurs when integer multiples of the original signal are generated, commonly referred to as Amplitude Distortion.

Intermodulation Distortion

  • Arises from the generation of unwanted frequency products when multiple signals mix in nonlinear devices.