What is pseudo noise 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.
What is pseudo noise sequence?
A pseudo-noise (PN) or pseudorandom sequence is a binary sequence with an autocorrelation that resembles, over a period, the autocorrelation of a random binary sequence. Its autocorrelation also roughly resembles the autocorrelation of bandlimited white noise.
How do you generate a pseudo noise sequence?
Description. The PN Sequence Generator block generates a sequence of pseudorandom binary numbers using a linear-feedback shift register (LFSR). Pseudonoise sequences are typically used for pseudorandom scrambling, and in direct-sequence spread-spectrum systems. For more information, see More About.
What is pseudorandom PN sequence and explain its properties?
The pseudorandom number (PN) sequence, which spreads the signal, is the key element to get these good properties of the SS system. This is conventionally generated by a linear feedback shift register (LFSR) which generates known sequences like the Gold and Kasami sequences and the Golden code ones [2,3].
Why PN sequence is called pseudo?
ese types of signals are called “pseudo-random” signals. Because of their noise-like characteristics they are also called pseudo-noise (PN) signals. A pseudo-random bit sequence (PRBS) is a two- valued (0,1) PN signal. PN and PRBS signals have many important applications in communications systems.
What are pseudo noise sequences why they are used in spread spectrum modulation?
The pseudo-random sequence is referred to as the spreading code or a pseudo-noise sequence. The energy of the signal is equally divided among different frequencies. An FHSS system consists of a modulator that uses a standard modulation technique to produce a signal centered around some base frequency.
What is pseudo-random code used for?
Pseudo-random numbers provide necessary values for processes that require randomness, such as creating test signals or for synchronizing sending and receiving devices in a spread spectrum transmission.
What is direct sequence spread spectrum technology?
Direct sequence spread spectrum (DSSS) is a transmission technology used in local area wireless network transmissions. In this technology, a data signal at the sending station is combined with a high data rate bit sequence, which divides user data based on a spreading ratio.
What is pseudo random code used for?
What is spread spectrum in data communication?
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 is a pseudo noise sequence used for?
Pseudo-Noise Sequence. A coded sequence of 1s and 0s with certain auto-correlation properties, called as Pseudo-Noise coding sequence is used in spread spectrum techniques. It is a maximum-length sequence, which is a type of cyclic code.
What is direct sequence spread spectrum (DSSS)?
In direct sequence spread spectrum (DSSS), the transmitter and receiver contain identical psuedo-random sequence generators producing a pseudo-noise (PN) signal. In the transmitter, the input data stream is XORed with the PN signal before transmission.
How to understand spread spectrum modulation?
Spread Spectrum Modulation 1 Narrow-band and Spread-spectrum Signals. Both the Narrow band and Spread spectrum signals can be understood easily by observing their frequency spectrum as shown in the following figures. 2 FHSS and DSSS / CDMA. 3 Comparison between FHSS and DSSS/CDMA.
What are the characteristics of spread spectrum signals?
The spread spectrum signals have the signal strength distributed as shown in the following frequency spectrum figure. Band of signals occupy a wide range of frequencies. Power density is very low. Energy is wide spread. With these features, the spread spectrum signals are highly resistant to interference or jamming.