Degree Type

Dissertation

Date of Award

1982

Degree Name

Doctor of Philosophy

Department

Electrical and Computer Engineering

Abstract

In this thesis, the atmospheric anisotropy and its effect on the delay power spectra of signals received on troposcatter radio links have been studied. A simplified model for determining an anisotropy coefficient is suggested. Theoretical and measured anisotropy profiles are utilized in the calculations of the delay power spectra of tropospheric links;The simplified anisotropic model offers definite advantages for extracting the anisotropy coefficient. One advantage is the evaluation of the anisotropy coefficient using data from a single time delay shell. Another advantage lies in the relative ease of implementing the inversion process;The impact of the anisotropy on the troposcatter channel as a communication link is studied. Bello's model for the troposcatter channel is modified to include the effect of the anisotropy on the delay power spectra. Several theoretical anisotropy profiles based on the experimental observations and the corresponding spectra are evaluated. It has been found that the anisotropy will result in increased multipath spread and mean delay parameters. This will have a direct effect on the irreducible bit error rate (BER) due to intermodulation distortion. Our calculations indicate that an order of magnitude increase in the BER due to the atmospheric anisotropy could result.

DOI

https://doi.org/10.31274/rtd-180813-5677

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Hosny Mohammed Ibrahim

Language

en

Proquest ID

AAI8224225

File Format

application/pdf

File Size

140 pages

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