Understanding Spread Spectrum Techniques

What is Frequency Hopping Spread Spectrum (FHSS)?

• Frequency Hopping Spread Spectrum (FHSS) is a method of transmitting radio signals by rapidly switching frequencies to reduce interference and enhance security.

• A system that relies on fixed frequencies to avoid interference.

• A technique that involves using infrared signals for communication.

• A method of transmitting signals using a single frequency for clarity.

How does Direct Sequence Spread Spectrum (DSSS) work?

• DSSS encrypts data to prevent unauthorized access.

• DSSS compresses data into a single frequency channel.

• DSSS modulates data with a pseudo-random code to spread the signal over a wider bandwidth.

• DSSS uses frequency hopping to transmit data.

What are the main differences between FHSS and DSSS?

• FHSS and DSSS both use frequency hopping techniques.

• FHSS uses frequency hopping, while DSSS uses direct sequence spreading.

• DSSS uses time division multiplexing, while FHSS uses frequency division multiplexing.

• FHSS uses direct sequence spreading, while DSSS uses frequency hopping.

List one application of Frequency Hopping Spread Spectrum.

• Infrared data transfer

• Bluetooth communication

• Satellite communication

• Wi-Fi networking

How does spread spectrum technology enhance security in communications?

• It makes signals harder to intercept and jam by spreading them over a wide frequency range.

• It encrypts the data to prevent unauthorized access.

• It increases the bandwidth of the signal for faster transmission.

• It reduces the power consumption of communication devices.

What are the advantages of using spread spectrum techniques?

• Increased latency in communication

• Higher power consumption

• Limited range of transmission

• Advantages of using spread spectrum techniques include resistance to interference, improved security, better multipath performance, and efficient bandwidth sharing.

Explain how spread spectrum can reduce interference.

• Spread spectrum compresses the signal into a narrow band, reducing its range of transmission.

• Spread spectrum reduces interference by spreading the signal over a wide frequency range, making it less susceptible to narrowband interference.

• Spread spectrum increases the signal strength, making it immune to all types of interference.

• Spread spectrum uses a single frequency to transmit data, which enhances clarity.

What role does a pseudo-random sequence play in DSSS?

• A pseudo-random sequence modulates the data signal in DSSS, spreading it over a wider bandwidth for improved resistance to interference.

• A pseudo-random sequence is used to synchronize the receiver with the transmitter in DSSS.

• A pseudo-random sequence reduces the bandwidth of the data signal in DSSS, allowing for faster transmission.

• A pseudo-random sequence encrypts the data signal in DSSS, making it unreadable to unauthorized users.

How does FHSS improve resistance to jamming?

• FHSS increases power output to overpower jamming signals.

• FHSS improves resistance to jamming by rapidly changing frequencies, making it hard for jammers to disrupt the signal.

• FHSS uses a single frequency to transmit data, making it easier to jam.

• FHSS relies on a constant frequency to maintain a stable connection.

Describe a scenario where spread spectrum is beneficial.

• Spread spectrum is primarily used in wired networks for faster data transfer.

• Spread spectrum is beneficial in military communications to enhance security and reduce interference.

• Spread spectrum is used in traditional radio broadcasting to increase range.

• Spread spectrum is beneficial for reducing costs in telecommunications.