Noise margin

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The technical term Noise Margin (German about reserve a signal level to the noise level ) designated in the Telecommunications those levels to which a useful signal to a information receiver to be larger than a disturbance variable, in order error free reception to enable the useful signal. The noise is a physical quantity of noise (Engl. Noise described).

In other words, the noise margin represents a lower limit of the signal-to-noise ratio that the receiver needs for error-free reception of the transmitted information. If the signal-to-noise ratio is smaller than the noise margin, there will be transmission errors during data transmission. The noise margin can become too small due to the effect of a disturbance that is too large, such as noise, or due to the attenuation of the useful signal level in the transmission channel .

Like the signal-to-noise ratio, the noise margin is measured as a dimensionless quantity in the unit Bel . In the telecommunications sector , for example with digital subscriber lines (DSL), this value should not fall below 3 dB to 4 dB.

literature

  • Howard W. Johnson, Martin Graham: High-Speed ​​Digital Design. A Handbook of Black Magic . 1st edition. Prentice Hall PTR, Englewood Cliffs NJ et al. 1993, ISBN 0-13-395724-1 , pp. 264 .
  • Andrei Pavlov, Manoj Sachdev: CMOS SRAM. Circuit Design and Parametric Test in Nano-Scaled Technologies, Springer Science + Business Media BV, New York 2008, ISBN 978-1-4020-8362-4 .
  • William J. Dally, John W. Poulton: Digital Systems Engineering. Cambridge University Press, Cambridge 1998, ISBN 0-521-59292-5 .