Fano noise
Fano noise is a fluctuation of an electric charge obtained in a detector (in spite of constant value of the measured quantity, which is usually an energy), arising from processes in the detector. It w
D/U ratio
In the design of radio broadcast systems, especially television systems, the desired-to-undesired channel ratio (D/U ratio) is a measure of the strength of the broadcast signal for a particular channe
Excess noise ratio
In electronics, excess noise ratio is a characteristic of a noise generator such as a "noise diode", that is used to measure the noise performance of amplifiers. The Y-factor method is a common measur
Noise shaping
Noise shaping is a technique typically used in digital audio, image, and video processing, usually in combination with dithering, as part of the process of quantization or bit-depth reduction of a dig
Atmospheric noise
Atmospheric noise is radio noise caused by natural atmospheric processes, primarily lightning discharges in thunderstorms. On a worldwide scale, there are about 40 lightning flashes per second – ≈3.5
Internet background noise
Internet background noise (IBN, also known as Internet background radiation) consists of data packets on the Internet which are addressed to IP addresses or ports where there is no network device set
Johnson–Nyquist noise
Johnson–Nyquist noise (thermal noise, Johnson noise, or Nyquist noise) is the electronic noise generated by the thermal agitation of the charge carriers (usually the electrons) inside an electrical co
Mode partition noise
Mode partition noise: In an optical communication link, is phase jitter of the signal caused by the combined effects of mode hopping in the and in the fiber. Mode hopping causes random wavelength chan
Phonon noise
Phonon noise, also known as thermal fluctuation noise, arises from the random exchange of energy between a thermal mass and its surrounding environment. This energy is quantized in the form of phonons
Circuit noise level
At any point in a transmission system, the ratio of the circuit noise at that point to an arbitrary level chosen as a reference. The circuit noise level is usually expressed in dBrn0, signifying the r
Psophometric voltage
Psophometric voltage is a circuit noise voltage measured with a psophometer that includes a CCIF-1951 weighting network. "Psophometric voltage" should not be confused with "psophometric emf," i.e., th
Shot noise
Shot noise or Poisson noise is a type of noise which can be modeled by a Poisson process. In electronics shot noise originates from the discrete nature of electric charge. Shot noise also occurs in ph
Colors of noise
In audio engineering, electronics, physics, and many other fields, the color of noise or noise spectrum refers to the power spectrum of a noise signal (a signal produced by a stochastic process). Diff
Channel noise level
In telecommunications, the term channel noise level has the following meanings: 1.
* The ratio of the noise in the communication channel at any point in a transmission system to an arbitrary level ch
Noise-equivalent power
Noise-equivalent power (NEP) is a measure of the sensitivity of a photodetector or detector system. It is defined as the signal power that gives a signal-to-noise ratio of one in a one hertz output ba
Neuronal noise
Neuronal noise or neural noise refers to the random intrinsic electrical fluctuations within neuronal networks. These fluctuations are not associated with encoding a response to internal or external s
Quantization (signal processing)
Quantization, in mathematics and digital signal processing, is the process of mapping input values from a large set (often a continuous set) to output values in a (countable) smaller set, often with a
Noise floor
In signal theory, the noise floor is the measure of the signal created from the sum of all the noise sources and unwanted signals within a measurement system, where noise is defined as any signal othe
Phase noise
In signal processing, phase noise is the frequency-domain representation of random fluctuations in the phase of a waveform, corresponding to time-domain deviations from perfect periodicity (jitter). G
Pink noise
Pink noise or 1⁄f noise is a signal or process with a frequency spectrum such that the power spectral density (power per frequency interval) is inversely proportional to the frequency of the signal. I
Noise power
In telecommunication, the term noise power has the following meanings: 1.
* The measured total noise in a given bandwidth at the input or output of a device when the signal is not present; the integr
Reference noise
In telecommunication, reference noise is the magnitude of circuit noise chosen as a reference for measurement. Many different levels with a number of different weightings are in current use, and care
Effective number of bits
Effective number of bits (ENOB) is a measure of the dynamic range of an analog-to-digital converter (ADC), digital-to-analog converter, or their associated circuitry. The resolution of an ADC is speci
Burst noise
Burst noise is a type of electronic noise that occurs in semiconductors and ultra-thin gate oxide films. It is also called random telegraph noise (RTN), popcorn noise, impulse noise, bi-stable noise,
Transient noise
Transient noise pulses consist of a relatively short pulse followed by decaying low frequency oscillations. The initial peak is often due to an impulse interference, and the following oscillations are
Pseudorandom 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, pse
Degradation (telecommunications)
In telecommunication, degradation is the loss of quality of an electronic signal, which may be categorized as either "graceful" or "catastrophic", and has the following meanings: 1.
* The deteriorati
Radio noise
In radio reception, radio noise is unwanted random radio frequency electrical signals, fluctuating voltages, always present in a radio receiver in addition to the desired radio signal. Radio noise nea
Noise (electronics)
In electronics, noise is an unwanted disturbance in an electrical signal. Noise generated by electronic devices varies greatly as it is produced by several different effects. In particular, noise is i
Psophometer
In telecommunications, a psophometer is an instrument that measures the perceptible noise of a telephone circuit. The core of the meter is based on a true RMS voltmeter, which measures the level of th
Brownian noise
In science, Brownian noise, also known as Brown noise or red noise, is the type of signal noise produced by Brownian motion, hence its alternative name of random walk noise. The term "Brown noise" doe
Psophometric weighting
Psophometric weighting refers to any weighting curve used in the measurement of noise. In the field of audio engineering it has a more specific meaning, referring to noise weightings used especially i
Spurious tone
In electronics (radio in particular), a spurious tone (also known as an interfering tone, a continuous tone or a spur) denotes a tone in an electronic circuit which interferes with a signal and is oft
Modulated Noise Reference Unit
Modulated Noise Reference Unit (MNRU) is an ITU standard (ITU P.810). The MNRU is, as the name implies, a noise model that utilizes speech as well as noise as input. The modulated output noise is a re
Noise figure
Noise figure (NF) and noise factor (F) are figures of merit that indicate degradation of the signal-to-noise ratio (SNR) that is caused by components in a signal chain. These figures of merit are used
Eb/N0
In digital communication or data transmission, (energy per bit to noise power spectral density ratio) is a normalized signal-to-noise ratio (SNR) measure, also known as the "SNR per bit". It is especi
Noise spectral density
In communications, noise spectral density (NSD), noise power density, noise power spectral density, or simply noise density (N0) is the power spectral density of noise or the noise power per unit of b
Equivalent pulse code modulation noise
In telecommunication, equivalent pulse code modulation (PCM) noise is the amount of noise power on a frequency-division multiplexing (FDM) or wire communication channel necessary to approximate the sa
Rustle noise
Rustle noise is noise consisting of aperiodic pulses characterized by the average time between those pulses (such as the mean time interval between clicks of a Geiger counter), known as rustle time (S
Interference (communication)
In telecommunications, an interference is that which modifies a signal in a disruptive manner, as it travels along a communication channel between its source and receiver. The term is often used to re
Equivalent input
Equivalent input (also input-referred, referred-to-input (RTI), or input-related), is a method of referring to the signal or noise level at the output of a system as if it were due to an input to the
Impulse noise (acoustics)
Impulse noise is a category of (acoustic) noise that includes unwanted, almost instantaneous (thus impulse-like) sharp sounds (like clicks and pops)—typically caused by electromagnetic interference, s
Simulation noise
Simulation noise is a function that creates a divergence-free vector field. This signal can be used in artistic simulations for the purposes of increasing the perception of extra detail. The function
White noise machine
A white noise machine is a device that produces a noise that calms the listener, which in many cases sounds like a rushing waterfall or wind blowing through trees, and other serene or nature-like soun
Relative intensity noise
Relative intensity noise (RIN), describes the instability in the power level of a laser. The noise term is important to describe lasers used in fiber-optic communication and LIDAR remote sensing. Rela
Additive white Gaussian noise
Additive white Gaussian noise (AWGN) is a basic noise model used in information theory to mimic the effect of many random processes that occur in nature. The modifiers denote specific characteristics:
Quantum 1/f noise
Quantum 1/f noise is an intrinsic and fundamental part of quantum mechanics. Fighter pilots, photographers, and scientists all appreciate the higher quality of images and signals resulting from the co
Signal-to-interference-plus-noise ratio
In information theory and telecommunication engineering, the signal-to-interference-plus-noise ratio (SINR) (also known as the signal-to-noise-plus-interference ratio (SNIR)) is a quantity used to giv
Clock feedthrough
In analog electronics, Clock feedthrough is the result of the coupling between control signals on the analog switch and analog signal passing through the switch. In digital electronics, clock feedthro
Flicker noise
Flicker noise is a type of electronic noise with a 1/f power spectral density. It is therefore often referred to as 1/f noise or pink noise, though these terms have wider definitions. It occurs in alm
Noise temperature (antenna)
In radio frequency (RF) applications such as radio, radar and telecommunications, noise temperature of an antenna is a measure of the noise power density contributed by the antenna to the overall RF r
Grey noise
Grey noise is random noise whose frequency spectrum follows an equal-loudness contour (such as an inverted A-weighting curve). The result is that grey noise contains all frequencies with equal loudnes
Oscillator phase noise
Oscillators produce various levels of phase noise, or variations from perfect periodicity. Viewed as an additive noise, phase noise increases at frequencies close to the oscillation frequency or its h
SINADR
Signal-to-noise and distortion ratio (SINADR) is a measurement of the purity of a signal. SINADR is typically used in data converter specifications. SINADR is defined as: where is the average power of
Received noise power
In telecommunications, received noise power is a measure of noise in a receiver. For example, the received noise power might be: 1.
* The calculated or measured noise power, within the bandwidth bein
Friis formulas for noise
Friis formula or Friis's formula (sometimes Friis' formula), named after Danish-American electrical engineer Harald T. Friis, is either of two formulas used in telecommunications engineering to calcul
Disturbance voltage
In telecommunication, a disturbance voltage is an unwanted voltage induced in a system by natural or man-made sources. In telecommunications systems, the disturbance voltage creates currents that limi
Signal-to-quantization-noise ratio
Signal-to-quantization-noise ratio (SQNR or SNqR) is widely used quality measure in analysing digitizing schemes such as pulse-code modulation (PCM). The SQNR reflects the relationship between the max
Generation–recombination noise
Generation–recombination noise, or g–r noise, is a type of electrical signal noise caused statistically by the fluctuation of the generation and recombination of electrons in semiconductor-based photo
Desensitization (telecommunications)
In telecommunications, desensitization (also known as receiver blocking) is a form of electromagnetic interference where a radio receiver is unable to receive a weak radio signal that it might otherwi
Noise (spectral phenomenon)
Noise refers to many types of random, troublesome, problematic, or unwanted signals. Acoustic noise may mar aesthetic experience, such as attending a concert hall. It may also be a medical issue inher
Switching noise jitter
Switching Noise Jitter (SNJ) is the aggregation of variability of noise events in the time-domain on the supply bias of an electronic system, in particular with a voltage regulated supply bias incorpo
Signal-to-noise ratio
Signal-to-noise ratio (SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal powe
White noise
In signal processing, white noise is a random signal having equal intensity at different frequencies, giving it a constant power spectral density. The term is used, with this or similar meanings, in m
Effective input noise temperature
In telecommunications, effective input noise temperature is the source noise temperature in a two-port network or amplifier that will result in the same output noise power, when connected to a noise-f
SINAD
Signal-to-noise and distortion ratio (SINAD) is a measure of the quality of a signal from a communications device, often defined as where is the average power of the signal, noise and distortion compo
Carrier-to-noise ratio
In telecommunications, the carrier-to-noise ratio, often written CNR or C/N, is the signal-to-noise ratio (SNR) of a modulated signal. The term is used to distinguish the CNR of the radio frequency pa
Noise generator
A noise generator is a circuit that produces electrical noise (i.e., a random signal). Noise generators are used to test signals for measuring noise figure, frequency response, and other parameters. N
Noise temperature
In electronics, noise temperature is one way of expressing the level of available noise power introduced by a component or source. (This is to be distinguished from Temperature Noise in Thermodynamics
Equivalent noise resistance
In telecommunication, an equivalent noise resistance is a quantitative representation in resistance units of the spectral density of a noise-voltage generator, given bywhere is the spectral density, i