What is spread spectrum and its types?

Spread Spectrum can be categorized into two types: Frequency Hopping Spread Spectrum (FHSS) Direct Sequence Spread Spectrum(DSSS)

Which technique is most popular for spread spectrum?

Frequency-Hopping Spread Spectrum (FHSS) The latter method, the most common, allows several consecutive data bits to modulate the same frequency. FFHSS is characterized by several hops within each data bit. The transmitted spectrum of a frequency-hopping signal is quite different from that of a direct-sequence system.

How many types of spread spectrum techniques are used in CDMA?

The DS-CDMA system uses two types of spreading sequences, i.e., PN sequences and orthogonal codes. As mentioned above, the PN sequenc is generated by the pseudo-random noise generator.

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.

What is the role of spread spectrum?

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.

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. While there is room for 11 overlapping channels in this 83 MHz-wide band, there is only room for three non-overlapping channels.

What are the applications of spread spectrum modulation?

Spread spectrum communication systems are widely used today in a variety of applications for different purposes such as access of same radio spectrum by multiple users (multiple access), anti-jamming capability (so that signal transmission can not be interrupted or blocked by spurious transmission from enemy).

Why CDMA is called spread spectrum?

To permit this without undue interference between the users, CDMA employs spread spectrum technology and a special coding scheme (where each transmitter is assigned a code). CDMA optimizes the use of available bandwidth as it transmits over the entire frequency range and does not limit the user’s frequency range.

Why spread spectrum is used?

How is spread spectrum used in WiFi?

What are the applications and advantages of spread spectrum techniques?

Advantages and applications of spread spectrum

• Spread spectrum signals are highly resistant to the jamming.
• Many users can share a signal band with no interference.
• Unauthorized listening is prevented.
• Unintentional interference occupying the same band is greatly minimized and in most cases virtually eliminated.

What are the advantages of spread spectrum transmissions?

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. An intruder with no official access is never allowed to crack them.

What is spread spectrum used for?

Spread spectrum is a technology originally developed for military applications to provide secure communications by spreading the transmitted signal over a large frequency band. This spread signal is not clearly distinguishable in the spectrum, and consequently more difficult to jam or intercept.

What are the disadvantages of spread spectrum?

The Direct Sequence Spread Spectrum or DSSS system takes large acquisition time; that’s why its performance is slow.

It requires wide-band channels with small phase distortion.

In DSSS,the pseudo-noise generator generates a sequence at high rates.

What is spread spectrum technology?

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.

Who invented spread spectrum technology?

Spread spectrum technology saw further development and deployment during World War II. Probably the most famous developer of spread spectrum technology was the actress Hedy Lamarr, who co-patented a frequency hopping technique in 1942 to prevent radio-controlled torpedoes from being detected and jammed.