What is PN code in CDMA?

CDMA code types There are several types of codes that can be used within a CDMA system for providing the spreading function: PN codes: Pseudo-random number codes (pseudo-noise or PN code) can be generated very easily. These codes will sum to zero over a period of time.

What is pseudo-noise code sequence?

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 CDMA uses orthogonal codes?

Each user in synchronous CDMA uses a code orthogonal to the others’ codes to modulate their signal. An example of 4 mutually orthogonal digital signals is shown in the figure below.

What is Walsh code in CDMA?

Walsh Code is a group of spreading codes having good autocorrelation properties and poor cross correlation properties. Walsh codes are the backbone of CDMA systems and are used to develop the individual channels in CDMA. For IS-95, there are 64 codes available.

How is pseudo noise sequence generated?

The pseudo-noise sequence is generated at the output of last flip-flop in the shift register. At each pulse of the clock, the state of the flip-flop is shifted to the next flip-flop and logic circuit output is shifted in the first flip-flop.

What does pseudo-noise code do?

This code allows any receiver to identify exactly which satellite(s) it is receiving. The PRN codes act as spreading codes in the spread-spectrum communications system, and must be carefully chosen to minimise interference between each satellite signal.

How is pseudo-noise sequence generated?

What does pseudo noise code do?

How is pseudo random noise code usable?

To be usable for direct-sequence spreading, a PN code must meet the following constraints: The sequences must be building from 2-leveled numbers. The codes must have a sharp (1-chip wide) autocorrelation peak to enable code synchronization.

What is Walsh code for CDMA?

What is meant by pseudo-noise?

In cryptography, pseudorandom noise (PRN ) is a signal similar to noise which satisfies one or more of the standard tests for statistical randomness. Although it seems to lack any definite pattern, pseudorandom noise consists of a deterministic sequence of pulses that will repeat itself after its period.

What is CDMA noise and how is it treated?

Signals that do not contain the code matches are treated as noise and ignored. CDMA starts with an encoded narrowband signal; this spreads with the use of the PN codes to a bandwidth of 1.23 MHz. When the signal is received, it is filtered and processed to recover the desired signal.

What is pseudo-random noise (PN)?

A Pseudo-random Noise (PN) sequence is a sequence of binary numbers, e.g. ±1, which appears to be random; but it is in fact, perfectly deterministic. Frequency Hop spread Spectrum (FH-SS). If ‘u’ uses PSK for modulating the PN sequence, it results in DS-SS. If ‘u’ uses FSK for modulating the PN sequence, it results in FH-SS.

What is a pseudo-noise code?

By correlating a (delayed version of) the transmitted signal with the received signal, a precise round trip time to the remote location can be determined and thus the distance. 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.

What is a CDMA modulate code?

In CDMA technology, each user is assigned with a different code, the code which is being assigned or chosen by the user is very important to modulate the signal because it is related to the performance of the CDMA system.