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Intro to Spread Spectrum Communication

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• "Normal" radio communication
  • Normal way to use radio waves (wireless) to communicate:

    The sender transmits messages on One frequency          The receiver listens on one (same) frequency

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  • Consequence:

    When another node transmits the same frequency: Transmissions on the shared frequence will be lost

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• Military grade communication
  • Battlefield scenario: (jamming)

    Soldiers at the front line use radio communication to report the current situation back to the head quarters (tug away safely behind many line of defenses) The enemy will always try prevent the soldiers from reporting: The enemy will jam the transmission (= transmit garbage on the same frequency)

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  • Anti-Jamming communication:

    Anti-jamming technique: Transmit the signal using multiple frequencies This technique is called: spread-spectrum communication       (Spread the signal over a spectrum of frequencies) Wikipedia page: click here

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• Spread spectrum communication
  • Spread spectrum transmission:

    Spread-spectrum transmission: transmits a signal using multiple frequencies I.e.: the data is spread across different frequencies

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  • Techniques used to achieve "spread spectrum" transmission:

    Frequency hopping            Direct sequence