EC5.102 - Information and Communication | IC Lecture 1

Signals

Definition

Signals are a medium which carry something interesting to the receiver. Information in ‘transit’ is a signal or in other words signals carry information.

Examples

1. Time-based signals
   • Sound waves
   • EM Waves
   • Digital signals
   • Morse code
   • Electrical signals
   • Optical signals
2. Non-time oriented signals
   • Temperature at various points in a room (at constant time). It maps a point in 3D to a temperature.
   • Images. It maps a point in 2D to a parameter like colour, brightness, contrast.
   • Text or page in a book.
   • Video Signal. Depends on both space and time