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HUMAN-COMPUTER INTERACTION AND COMMUNICATION SYSTEMS

5. Components:

Components:

  1. Encoder: Converts the message into a coded format.
  2. Modulator: Converts the baseband signal to a passband signal suitable for transmission.
  • Examples: Radio towers, mobile phones, routers, modems.

Functions:

  • Signal processing (e.g., amplification, filtering).
  • Modulation (e.g., AM, FM, PM for analog; ASK, FSK, PSK for digital).

Examples: Radio transmitter, optical transmitter.

4. Transmission Medium (Channel)

  • The medium through which the signal travels from the sender to the receiver.
  • It can be wired (cables, fiber optics) or wireless (radio waves, satellite links).
  • Examples:
    • Wired: Ethernet cables, fiber optic cables.
    • Wireless: Wi-Fi, Bluetooth, satellite communication.

5. Noise (Interference)

Noise refers to unwanted disturbances that affect the signal during transmission. Unwanted signals that distort or interfere with the transmitted signal.

Types:

  • Internal Noise: Generated within the communication system (e.g., thermal noise).
  • External Noise: Comes from outside the system (e.g., atmospheric noise, industrial noise).
  • It can degrade the quality of the communication.

 Impact: Reduces the quality and reliability of the communication.

Mitigation Techniques:

  • Shielding: Protecting the system from external noise.
  • Filtering: Removing unwanted frequencies.

Examples: Electrical interference, atmospheric disturbances, cross-talk in wired communication.