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Driving these filters with independent, unit variance, band-limited white noise yields outputs with power spectral densities that approximate the power spectral densities of the velocity components of the von Kármán model. The outputs can, in turn, be used as wind disturbance inputs for aircraft or other dynamic systems. [10]
White noise draws its name from white light, [2] although light that appears white generally does not have a flat power spectral density over the visible band. An image of salt-and-pepper noise In discrete time , white noise is a discrete signal whose samples are regarded as a sequence of serially uncorrelated random variables with zero mean ...
Bandlimiting refers to a process which reduces the energy of a signal to an acceptably low level outside of a desired frequency range.. Bandlimiting is an essential part of many applications in signal processing and communications.
The channel capacity can be calculated from the physical properties of a channel; for a band-limited channel with Gaussian noise, using the Shannon–Hartley theorem. Simple schemes such as "send the message 3 times and use a best 2 out of 3 voting scheme if the copies differ" are inefficient error-correction methods, unable to asymptotically ...
Driving these filters with independent, unit variance, band-limited white noise yields outputs with power spectral densities that match the spectra of the velocity components of the Dryden model. The outputs can, in turn, be used as wind disturbance inputs for aircraft or other dynamic systems. [6]
Additive because it is added to any noise that might be intrinsic to the information system. White refers to the idea that it has uniform power spectral density across the frequency band for the information system. It is an analogy to the color white which may be realized by uniform emissions at all frequencies in the visible spectrum.
If one desired to sample an FM radio broadcast centered at 87.9 MHz and bandlimited to a 200 kHz band, then an appropriate anti-alias filter would be centered on 87.9 MHz with 200 kHz bandwidth (or passband of 87.8 MHz to 88.0 MHz), and the sampling rate would be no less than 400 kHz, but should also satisfy other constraints to prevent aliasing.
In the simple version above, the signal and noise are fully uncorrelated, in which case + is the total power of the received signal and noise together. A generalization of the above equation for the case where the additive noise is not white (or that the / is not constant with frequency over the bandwidth) is obtained by treating the channel as many narrow, independent Gaussian ...