- What is PN sequence?
- What is FHSS and DSSS?
- What is a jamming attack?
- What is processing gain in spread spectrum?
- What are the different spread spectrum techniques?
- What is meant by spread spectrum?
- What are the two types of spread spectrum?
- Why bit error rate of DSSS is poor?
- Why spread spectrum is used?
- Should I disable Spread Spectrum?
- What are the types of FHSS?
- What is jamming in communication?
- Does WIFI use spread spectrum?
- What is meant by jamming margin?
- What is jamming in spread spectrum?
- How is DSSS signal generated?
- Which is better for avoiding jamming?
What is PN sequence?
Theory: Pseudo-Noise (PN) sequences are commonly used to generate noise that is approximately “white”.
It has applications in scrambling, cryptography, and spread-spectrum communications.
It is also commonly.
referred to as the Pseudo-Random Binary Sequence (PRBS).
These are very widely used in communication..
What is FHSS and DSSS?
Two popular methods for using the spread spectrum are frequency-hopping spread spectrum (FHSS) and direct-sequence spread spectrum (DSSS). … DSSS, in contrast, spreads the signal across a wider bandwidth than FHSS, creating a lower power density across the spectrum.
What is a jamming attack?
A jamming attack is the transmission of radio signals that disrupt communications by decreasing the Signal-to-Inference-plus-Noise ratio (SINR) (Berg, 2008). SINR is the ratio of the signal power to the sum of the interference power from other interfering signals and noise power.
What is processing gain in spread spectrum?
Abstract: The processing gain of a spread-spectrum (SS) system is generally defined as the ratio between the transmission bandwidth and data bandwidth, and is a measure of its interference rejection capability.
What are the different spread spectrum techniques?
There are four techniques of spread spectrum namely direct sequence spread spectrum (DSSS), frequency hopping spread spectrum (FHSS), chirp spread spectrum (CSSS) and time hopping spread spectrum (THSS). … Chapter four discusses different multiple accesses of spread spectrum.
What is meant by spread spectrum?
Spread Spectrum refers to a system originally developed for military applications, to provide secure communications by spreading the signal over a large frequency band. … These narrowband signals are easily jammed by any other signal in the same band.
What are the two types of spread spectrum?
Out of many Spread Spectrums, this report analyses the two main spread spectrum systems which are the ‘Frequency Hopping and Direct Sequence’ and in addition an overview of the ‘Chirp Spread’ Spectrum.
Why bit error rate of DSSS is poor?
DS is self synchronizing but receiver synchronization in frequency hopping is more difficult. In DSSS, higher the chip rate of PN code, the smaller will be the degradation due to multipath and in FHSS if the carrier frequency of the transmitted signal hops fast enough then only multipath effect will be diminished.
Why spread spectrum is used?
The main advantage of spread spectrum communication technique is to prevent “interference” whether it is intentional or unintentional. The signals modulated with these techniques are hard to interfere and cannot be jammed. … These spread spectrum signals transmit at low power density and has a wide spread of signals.
Should I disable Spread Spectrum?
Generally, frequency modulation through spread spectrum clocking should not cause any problems. … Therefore, it is recommended that you disable the MCLK Spread Spectrum feature if you are overclocking the memory bus. You will be able to achieve better overclockability, at the expense of higher EMI.
What are the types of FHSS?
Explain FHSS different types of frequency hoping, advantages, disadvantages, Applications of FHSS system. Different bytes of frequency hopping:- Slow and fast frequency hopping. FHSS: It combines spread spectrum modulation with MFSK.
What is jamming in communication?
Radio jamming is the deliberate jamming, blocking or interference with authorized wireless communications. In some cases jammers work by the transmission of radio signals that disrupt communications by decreasing the signal-to-noise ratio. The concept can be used in wireless data networks to disrupt information flow.
Does WIFI use spread spectrum?
Bluetooth uses Frequency Hopping Spread Spectrum (FHSS) and is allowed to hop between 79 different 1 MHz-wide channels in this band. Wi-Fi uses Direct Sequence Spread Spectrum (DSSS) instead of FHSS. Its carrier does not hop or change frequency and remains centered on one channel that is 22 MHz-wide.
What is meant by jamming margin?
Jamming Margin (1/2) ◆ The level of interference (jamming) that a system is able to. accept and still maintain a specified level of performance, such as maintain specified bit-error ratio even though the signal-to-noise ratio is decreasing.
What is jamming in spread spectrum?
Jamming is a deliberate attempt to disrupt communication between the transmitter and the receiver. … Since spread spectrum signals are wide, they transmit at a much lower spectral power density, making it less likely to interfere with narrowband communications.
How is DSSS signal generated?
DSSS uses a signal structure in which the spreading sequence produced by the transmitter is already known by the receiver. The receiver can then use the same spreading sequence to counteract its effect on the received signal in order to reconstruct the information signal.
Which is better for avoiding jamming?
Explanation: Frequency hopping spread spectrum is better for avoiding jamming. … Explanation: Time hopping spread spectrum is more bandwidth efficient.