GPS Anti-Jamming Techniques Using Smart Antenna Systems
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Date
2019
Authors
Akobundu, G.C.
Gbenga-Ilori, A.O.
Journal Title
Journal ISSN
Volume Title
Publisher
AZOJETE, Faculty of Engineering, University of Maiduguri
Abstract
This paper presents a global positioning system (GPS) anti-jamming
technique using a smart antenna system. In anti-jamming systems,
adaptive array antennas are used to estimate the direction of signals
arriving at the antenna and spatially filter the desired signal from the
unwanted signals by adaptively controlling the direction of the
maximum radiated beam. In this study, the uniform linear array was
used for the smart antenna configuration. The work compared the
performance of non-blind adaptive algorithms with blind algorithms
for adaptive beamforming. Non-blind adaptive algorithm using least
mean square (LMS) algorithm and blind algorithm using constant
modulus algorithm (CMA) was studied and implemented for adaptive
beamforming while estimation of signal parameters via rotational
invariance technique (ESPRIT) and multiple signal classification (MUSIC)
algorithms were implemented for the direction of arrival (DOA)
estimation. The effect of varying the number of elements in the
antenna array and the required spacing between them was also
investigated. Results of comparison carried out using numerical
analysis showed that both algorithms performed well for the DOA
estimation, with MUSIC algorithm producing a better direction of
arrival spectrum with little or no minor peaks. For the beamforming,
both LMS and CMA produced maximum radiation in the direction of
the desired signal. LMS placed deeper nulls in the directions of
interference with faster convergence and fewer errors as compared
with CMA that presented errors and was able to suppress the
interference to a minimal extent. It was also shown that as the number
of elements in the array increases, a more directive beam and DOA
spectrum is produced.
Description
Keywords
Array antennas CMA DOA ESPRIT LMS MUSIC Beamforming