Pseudorandom noise
|
|
Pseudorandom noise 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.
This sequence is known as a chip and the inverse of its period as chip rate.
In cryptographic devices, pseudo-random noise is mixed with entropy to increase randomness.
Pseudorandom noise is used in some electronic musical instruments, either by itself or as an input to subtractive synthesis.
In spread-spectrum systems, modulated carrier transmissions appear as noise to any receiver that is:
- not locked on the transmitter frequencies; or
- incapable of correlating a locally generated pseudorandom sequence with the received signal.
A pseudonoise code is one that has a spectrum similar to a random sequence of bits but is deterministically generated.
See also: Pseudorandom number sequence, Pseudorandom number generator, n-sequence, Federal Standard 1037C, MIL-STD-188de:Pseudozufallsrauschen