# Browsing by Author "Vanelli, James Charles"

Now showing 1 - 2 of 2

- Results Per Page
1 5 10 20 40 60 80 100

- Sort Options
Ascending Descending

Item Binary data communication over an impulsive noise channel(1977) Vanelli, James Charles; Shehadeh, Nazmi M.; Hayre, Harbhajan S.; Donaghey, Charles E.; Batten, George W., Jr.; Townes, James R.Show more Useful analytical techniques for determining optimum signal parameter values in binary data communication over a channel corrupted by a combination of white Gaussian noise and impulsive noise are derived and presented in this dissertation. The analysis is based on a linear channel model and the optimality criterion used throughout is minimization of the decision error probability. A general expression for the probability of error is also obtained, based on the characteristic functions of the various noise and interference terms affecting the decision. Efficient numerical evaluation of this integral equation is made possible by the derivation of a suitable general expression for the characteristic function of the filtered impulsive noise component. Series expansions and a novel closed-form approximation of this characteristic function are also presented. The closed-form approximation applies to situations in which the composite response shaping the noise impulses is that of a Gaussian filter. This approximation yields the desired characteristic function with a maximum relative error of 0.5 percent. A common assumption in the analysis of impulsive noise channels is that at most one noise impulse occurs to affect a given decision. In practice this assumption is not always valid. However, in this work it is shown that optimum signal parameter values can be determined subject to the single noise impulse assumption and without regard to the white Gaussian noise component. The parameter values thus determined are optimum in a strict sense, with no restriction on the number of noise impulses that might actually occur to affect a given decision. Optimality tests based on the characteristic function of the filtered impulsive noise component are also derived. [...]Show more Item Intersymbol interference and the Rayleigh fading channel(1973) Vanelli, James Charles; Shehadeh, Nazmi M.; Anderson, Wallace L.; Donaghey, Charles E.Show more Presented herein is an analysis of the effects of intersymbol interference on the performance of digital communication systems operating over channels corrupted by Rayleigh fading and additive Gaussian noise. The results are applicable to systems employing coherent detection schemes. For mean signal-to-noise ratios of 15 dB or less, and for typical pulse shapes with reasonably well-synchronized sampling, intersymbol interference is shown to contribute no significant amount to the average probability of biterror over the Rayleigh fading channel. As the mean signal- to-noise ratio is Increased to higher levels, the Incremental bit-error probability caused by Intersymbol interference is seen to be limited to some fractional part of the total biterror probability. Under normal circumstances, this limiting fraction is itself not large, being less than 0.2 for most examples considered in this study. Such results contrast sharply with those obtained in the absence of fading, in which case the bit-error probability at signal-to-noise ratios in excess of 15 dB is almost entirely due to intersymbol interference. Of particular Interest is the numerical integration technique used to calculate the bit-error probabilities for both types of channel. This is a very simple, straightforward approach and appears to be superior in some respects to the more sophisticated schemes currently under discussion In the literature.Show more