1. Digital vs Analog Signals

Signals are:
- Stream of quantities in time or spatial sequence- Contain and transport information in coded form and are decoded in a detector or demodulator
Digital vs Analog
(a) Analog Signal
  • Wave is recorded or used in its original form
  • For example:
    > Signal is taken straight from the microphone and laid onto tape.
    >Wave on the tape can be read, amplified and sent to a speaker to produce the sound.

(b) Digital Signal
  • Analog wave is turned into numbers (electrical signals with amplitudes of 0 or 1) stored in the digital device
  • For example:
    > On a CD, the sampling rate is 44,000 samples per second, meaning 44,000 numbers are stored per second of music
    > To hear the music, the numbers are turned into a voltage wave that approximates the original wave.

external image Analog%20Digital.jpg

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