What is spread spectrum and its type?

What is spread spectrum and its type?

There are four generic types of spread spectrum signals: Direct Sequence (DS) – The carrier of a DS source stays at a fixed frequency. Narrowband information is spread out into a much larger bandwidth using a pseudo-random chip sequence. Pseudo noise (PN)

What are the 3 varieties of spread spectrum?

1- Frequency-hopping spread spectrum (FHSS) . 3- Time-hopping spread spectrum (THSS) . 4- Chirp spread spectrum (CSS) .

What are the spread spectrum techniques?

There are two main types of spread spectrum techniques that are employed. These are Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS).

What is a spread spectrum system?

Introduction. 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.

Where is spread spectrum used?

Spread-spectrum clock generation (SSCG) is used in some synchronous digital systems, especially those containing microprocessors, to reduce the spectral density of the electromagnetic interference (EMI) that these systems generate.

Why spread spectrum is used?

Spread Spectrum refers to a system originally developed for military applications, to provide secure communications by spreading the signal over a large frequency band. Figure 1 represents a narrow band signal in the frequency domain. These narrowband signals are easily jammed by any other signal in the same band.

Which technique is most popular for spread spectrum?

Direct sequence and frequency hopping are the most commonly used methods for the spread spectrum technology.

Which is better FHSS or DSSS?

DSSS, in contrast, spreads the signal across a wider bandwidth than FHSS, creating a lower power density across the spectrum. Because FHSS allows more channels in the same frequency band, FHSS systems can support a greater aggregate bandwidth for coverage.

What are the two types of spread spectrum techniques?

Spread Spectrum can be categorized into two types:

• Frequency Hopping Spread Spectrum (FHSS)
• Direct Sequence Spread Spectrum(DSSS)

Is LTE a spread spectrum?

LTE is a broadband wireless technology that uses wide channels to achieve high data rates and accommodate lots of users. The standard is set up to permit bandwidths of 1.4, 3, 5, 10, 15, and 20 MHz. The carrier selects the bandwidth depending on spectrum holdings as well as the type of service to be offered.

Is WIFI spread spectrum?

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.

Is WiFi spread spectrum?

What are the disadvantages of spread spectrum?

Disadvantages: It is need complex frequency synthesizers. Not useful for range and range rate measurements. It requires error correction.

Who invented the spread spectrum?

Hedy Lamarr Invention of Spread Spectrum Technology Although better known for her Silver Screen exploits, Austrian actress Hedy Lamarr (born Hedwig Eva Maria Kiesler) also became a pioneer in the field of wireless communications following her emigration to the United States.

What does spread spectrum communication mean?

Spread spectrum is a form of wireless communications in which the frequency of the transmitted signal is deliberately varied . This results in a much greater bandwidth than the signal would have if its frequency were not varied.

What is FHSS modulation?

FHSS is a Spread Spectrum modulation technique in which the data signal is hopped from one frequency to the other frequency after a specific interval of time, by making the signal resistant to noise, diffusion, multipath distortion, jamming and interception and makes an efficient use of frequency channels.