A communication system is a structured setup used to transfer information from one point to another. The basic structure involves nine components organised into a sequence that allows effective transmission and reception of signals. Here is an overview of each component, along with their roles in the communication process:

• Examples:
• Microphones for sound input.
• Cameras for visual input.
• Computers for digital data input.

• Examples:
• Aerials convert electrical signals to radio waves.
• Infrared LEDs or Laser diodes convert signals into light waves.

• Examples:
• Free Space for radio waves.
• Optical Fibres for light or infrared waves.
• Copper Wires for electrical signals.

• Examples:
• Aerials for radio waves.
• Photodiodes for light or infrared waves.

• Examples:
• Speakers convert electrical signals to sound.
• Printers convert electrical signals to mechanical outputs.
• Projectors convert electrical signals to light outputs.

Example Walk-through

Consider a communication system designed to transmit voice signals over long distances:

1. Input Transducer: A microphone captures the voice and converts it into an electrical signal.
2. Modulator: This signal is superimposed onto a carrier wave to prepare it for radio transmission.
3. Amplifier (Transmission): The signal's amplitude is increased to ensure it travels far enough without significant loss.
4. Transmitter: The modulated signal is sent out through an aerial as radio waves.
5. Transmission Path: The signal travels as radio waves through free space.
6. Receiver: An aerial at the receiving end detects the radio waves and converts them back to an electrical signal.
7. Amplifier (Receiver): This amplifier boosts the received signal, compensating for any attenuation that occurred during transmission.
8. Demodulator: The original voice signal is separated from the carrier wave, isolating it for final output.
9. Output Transducer: A speaker then converts the electrical signal back into sound, allowing the received voice to be heard.

Key Points for Communication Systems

• Attenuation: Loss of signal strength during transmission. Amplifiers are used to mitigate this.
• Modulation and Demodulation: Modulation allows efficient transmission over long distances, while demodulation recovers the original signal.
• Carrier Waves: Used in modulation to carry information. Examples include radio and light waves.
• Input and Output Transducers: Essential for converting information between physical signals (like sound or light) and electrical signals usable by the communication system.