 Noise spectral density

In communications, noise spectral density N_{o} is the noise power per unit of bandwidth; that is, it is the power spectral density of the noise. It has dimension of power/frequency (see dimensional analysis), whose SI coherent unit is watts per hertz, which is equivalent to wattseconds or joules. If the noise is white noise, i.e., constant with frequency, then the total noise power N in a bandwidth B is BN_{o}. This is utilized in signaltonoise ratio calculations.
The thermal noise density is given by N_{o} = kT, where k is Boltzmann's constant in joules per kelvin, and T is the receiver system noise temperature in kelvins.
N_{o} is commonly used in link budgets as the denominator of the important figureofmerit ratios E_{b}/N_{0} and E_{s}/N_{0}.
Noise (in physics and telecommunications) General Noise in... Class of noise Additive white Gaussian noise (AWGN) · Atmospheric noise · Background noise · Brownian noise · Burst noise · Cosmic noise · Flicker noise · Gaussian noise · Grey noise · Jitter · Johnson–Nyquist noise · Pink noise · Quantization error (or q. noise) · Shot noise · White noiseEngineering terms Ratios Carriertonoise ratio (C/N) · Carriertoreceiver noise density (C/kT) · dBrnC · Eb/N0 (energy per bit to noise density) · Es/N0 (energy per symbol to noise density) · Modulation error ratio (MER) · Signal, noise and distortion (SINAD) · Signaltointerference ratio (S/I) · Signaltonoise ratio (S/N, SNR) · Signal to noise ratio (imaging) · Signaltonoise plus interference (SNIR) · Signaltoquantizationnoise ratio (SQNR)Related topics Categories:
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