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单词 signal-to-noise ratio
释义

signal-to-noise ratio


sig·nal-to-noise ratio

(sĭg′nəl-tə-noiz′)n.1. The ratio of the power of an electrical, electromagnetic, or optical signal to the power of background noise accompanying the signal.2. The ease with which useful information can be discerned in the context of much noise, talk, or undesired information.

signal-to-noise ratio

n (Electronics) the ratio of one parameter, such as power of a wanted signal to the same parameter of the noise at a specified point in an electronic circuit, etc

signal-to-noise ratio

The ratio of the amplitude of the desired signal to the amplitude of noise signals at a given point in time.
Thesaurus
Noun1.signal-to-noise ratio - the ratio of signal intensity to noise intensitysignal-to-noise ratio - the ratio of signal intensity to noise intensityS/N, signal/noise, signal/noise ratio, signal-to-noiseratio - the relative magnitudes of two quantities (usually expressed as a quotient)

signal-to-noise ratio


signal-to-noise ratio

[′sig·nəl tə ′nȯiz ‚rā·shō] (electronics) The ratio of the amplitude of a desired signal at any point to the amplitude of noise signals at that same point; often expressed in decibels; the peak value is usually used for pulse noise, while the root-mean-square (rms) value is used for random noise. Abbreviated S/N; SNR.

Signal-to-noise ratio

The quantity that measures the relationship between the strength of an information-carrying signal in an electrical communications system and the random fluctuations in amplitude, phase, and frequency superimposed on that signal and collectively referred to as noise. For analog signals, the ratio, denoted S/N, is usually stated in terms of the relative amounts of electrical power contained in the signal and noise. For digital signals the ratio is defined as the amount of energy in the signal per bit of information carried by the signal, relative to the amount of noise power per hertz of signal bandwidth (the noise power spectral density), and is denoted Eb/N0. Since both signal and noise fluctuate randomly with time, S/N and Eb/N0 are specified in terms of statistical or time averages of these quantities.

The magnitude of the signal-to-noise ratio in a communications systems is an important factor in how well a receiver can recover the information-carrying signal from its corrupted version and hence how reliably information can be communicated. Generally speaking, for a given value of S/N the performance depends on how the information quantities are encoded into the signal parameters and on the method of recovering them from the received signal. The more complex encoding methods such as phase-shift keying or quadrature amplitude-shift keying usually result in better performance than simpler schemes such as amplitude- or frequency-shift keying. As an example, a digital communication system operating at a bit error rate of 10-5 requires as much as 7 dB less for Eb/N0 when employing binary phase-shift keying as when using binary amplitude-shift keying. See Electrical communications, Information theory

signal-to-noise ratio (S/N ratio)

The ratio, at a selected point in the circuit, of signal power to noise power. It measures the comprehensibility of a data source or transmission link, usually expressed as the root-mean-square signal amplitude divided by the root-mean-square noise amplitude. The higher the S/N ratio, the less the interference with reception.

signal-to-noise ratio

(communications)(SNR, "s/n ratio", "s:n ratio") "Signal"refers to useful information conveyed by some communicationsmedium, and "noise" to anything else on that medium. Theratio of these is usually expressed logarithmically, indecibels.

signal-to-noise ratio

(networking)The term is often applied to Usenetnewsgroups though figures are never given. Here it is quitecommon to have more noise (inappropriate postings whichcontribute nothing) than signal (relevant, useful orinteresting postings). The signal gets lost in the noisewhen it becomes too much effort to try to find interestingarticles among all the crud. Posting "noise" is probably theworst breach of netiquette and is a waste of bandwidth.

signal-to-noise ratio

The ratio of the power or volume (amplitude) of a signal to the amount of disturbance (the noise) mixed in with it. Measured in decibels, signal-to-noise ratio (SNR, S/N) measures the clarity of the signal in a circuit or a wired or wireless transmission channel. See interference-to-noise ratio.

The Larger the Number, the Better
The greater the ratio (the larger number), the less noise and more easily it can be filtered out. The lowest number is an SNR of 0, which means that noise and signal levels are the same. Although signals contain non-random intelligence and can be isolated and separated, with a 0 SNR, it is more difficult to isolate the signal in real time and might be better handled in a batch process offline.

As a Metaphor (Quality vs. Junk)
The terms "signal" and "noise" are also commonly used to refer to meaningful content (signal) versus useless content (noise). For example, in a search engine result, signal refers to relevant results compared to the noise, which is information of little value. The terms can be applied to any quantity of material that is valuable versus that which is not.

signal-to-noise ratio


ratio

 [ra´she-o] (L.) an expression of the quantity of one substance or entity in relation to that of another; the relationship between two quantities expressed as the quotient of one divided by the other.A/D ratio adult versus developmental toxicity ratio; the ratio between the toxic effects of a substance on adults (humans or animals, especially pregnant females) and such effects on developing embryos or fetuses.A-G ratio (albumin-globulin ratio) the ratio of albumin to globulin in blood serum, plasma, cerebrospinal fluid, or urine.arm ratio a figure expressing the relation of the length of the longer arm of a mitotic chromosome to that of the shorter arm.benefit-risk ratio a determination of the potential of a research study for positive effects on patients compared to the risks of doing harm.cardiothoracic ratio on a chest radiograph, the ratio of the transverse diameter of the heart to the internal diameter of the chest at its widest point just above the dome of the diaphragm.grid ratio a ratio comparing the height of lead lines in an x-ray grid to the distance between the lead strips.inspiratory-expiratory ratio the ratio of the inspiratory time to the expiratory time during the breathing cycle. Normally, expiratory time will be longer than inspiratory time; if the inspiratory time is longer than the expiratory time, gas trapping may result.lecithin/sphingomyelin ratio see lecithin-sphingomyelin ratio.risk ratio relative risk.sex ratio the proportion of one sex to the other; by tradition the number of males in a population to the number of females, usually stated as the number of males per 100 females.signal-to-noise ratio the ratio between the amplitude of a signal being measured and that of the noise.urea excretion ratio the ratio of the amount of urea in the urine excreted in one hour to the amount in 100 ml of blood. The normal ratio is 50.zeta sedimentation ratio (ZSR) a measurement comparable to the erythrocyte sedimentation rate, except that it is unaffected by anemia. The packed-cell volume (zetacrit) of a blood specimens is calculated by centrifuging the specimen in a Zetafuge, a specially designed instrument that produces controlled cycles of compaction and dispersion and allows rouleaux to form and sediment rapidly. The zetacrit divided into the true hematocrit gives the zeta sedimentation ratio.

signal-to-noise ratio

An MRI term for the ratio between the amplitude of the received signal and background noise, which may obscure that signal. SNR, and by extension, image quality, can be improved by increasing the number of excitations, field of view, slice thickness, etc., while factoring the electrical properties of the patient being studied and type of receiving coil used.

signal-to-noise ratio

MRI The ratio obtained from the relative contributions of detected true signal to that of random superimposed signals–'noise'. See Magnetic resonance imaging.
FinancialSeeratioSee SNR
See SNR

signal-to-noise ratio


  • noun

Synonyms for signal-to-noise ratio

noun the ratio of signal intensity to noise intensity

Synonyms

  • S/N
  • signal/noise
  • signal/noise ratio
  • signal-to-noise

Related Words

  • ratio
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更新时间:2025/1/12 10:17:00