What is direct sequence spread spectrum technique?

What is direct sequence spread spectrum technique?

In telecommunications, direct-sequence spread spectrum (DSSS) is a spread-spectrum modulation technique primarily used to reduce overall signal interference. Each spreading-sequence bit, which is known as a chip, has a much shorter duration (larger bandwidth) than the original message bits.

How the direct sequence spread spectrum is implemented?

Direct sequence spread spectrum (DSSS) transmission employs a chipping code to “spread” the transmission over a wider frequency band than it would normally occupy. DSSS is a form of CDMA (see Chapter 4). But instead of a pseudorandom binary sequence (PRBS), an 11-bit Barker code is used as the spreading sequence.

What are the two types of spread spectrum techniques?

2.2 SPREAD SPECTRUM TECHNOLOGIES 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).

Which of the following is advantage of direct sequence spread spectrum?

Following are the benefits or advantages of DSSS: ➨It uses both time and frequency planes for transmission of information bits, effect of interference and fading can be minimized to great extent. ➨It can be employed in point to point applications at the rate of 11 Mbps.

What is a role of PN sequence in Dsss?

Pseudorandom noise (PN) sequences are used to spread and recover data in direct-sequence spread spectrum (DSSS) transceivers. We consider the problem of designing multiple PN sequences that are to be used as pilot signals and spreading sequences for transceivers whose clocks are not synchronized.

What is PN sequence in spread spectrum?

A pseudo-noise code (PN code) or pseudo-random-noise code (PRN code) is one that has a spectrum similar to a random sequence of bits but is deterministically generated. The most commonly used sequences in direct-sequence spread spectrum systems are maximal length sequences, Gold codes, Kasami codes, and Barker codes.

Which spread spectrum broadcasting method is the latest method?

OFDM is the latest method and combines the multiple frequencies of DSSS with FHSS’s hopping capability.

How is the direct sequence spread spectrum used?

In telecommunications, direct-sequence spread spectrum ( DSSS) is a spread-spectrum modulation technique primarily used to reduce overall signal interference. The direct-sequence modulation makes the transmitted signal wider in bandwidth than the information bandwidth. After the despreading or removal of the direct-sequence modulation in

How does direct sequence modulation affect the bandwidth?

The direct-sequence modulation makes the transmitted signal wider in bandwidth than the information bandwidth. After the despreading or removal of the direct-sequence modulation in the receiver, the information bandwidth is restored, while the unintentional and intentional interference is substantially reduced.

Who was the first person to use direct sequence modulation?

After the despreading or removal of the direct-sequence modulation in the receiver, the information bandwidth is restored, while the unintentional and intentional interference is substantially reduced. The first known scheme for this technique was introduced by a Swiss inventor, Gustav Guanella.

Can a spread spectrum signal occupy the same band?

Spread-spectrum and narrowband signals can occupy the same band, with little or no interference. This capability is the main attraction for all the interest in spread spectrum today. The transmitted signal bandwidth is greater than the minimal information bandwidth, which is needed to transmit the signal successfully.