Abstract
Global Positioning System (GPS) signals are spread spectrum, modulated with very low average power caused by background noise. Signal received is mostly 165 dB down than thermal noise level. Such signals are easily jammed either through intentional noise sources (jammer) or unintentionally from broadcasting stations harmonics or other out of band sources. This study proposes to reveal how a nulling antenna with adaptive spatial filtering technique can efficiently mitigate intentional and non-intentional interference. A beam forming antenna array is an antennas set whose outputs are weighted by complex values and combined form array output. The complex valued weights effect is to steer the array pattern’s main lobes to desired directions which may be unknown and hence antenna weights are adjusted adaptively till some array performance measure is improved, revealing proper lobe or null placement. This study proposes a Cuckoo Search (CS) algorithm based new optimization method for multiple interference cancellation design that increases gain to desired signal and improves jamming rejection performance.
Highlights
Global Positioning System (GPS) is an earthorbiting-satellite based navigation system which provides users globally with 24 h precise time, traceable to global time standards and precise position in three dimensions
The GPS is operated by United States Air Force under the Department of Defence (DoD)
A fraction of jamming signal that makes it through a GPS receiver becomes additive to noise floor, degrading output Signal-to-Interference power Ratio (SIR) and corresponding receiver operation
Summary
Global Positioning System (GPS) is an earthorbiting-satellite based navigation system which provides users globally with 24 h precise time, traceable to global time standards and precise position in three dimensions. Though wideband jamming is regarded for low power spectral density, it is practically impossible to filter it out through embedded receiver signal processing techniques. A fraction of jamming signal that makes it through a GPS receiver (and into base band processing functions) becomes additive to noise floor, degrading output Signal-to-Interference power Ratio (SIR) and corresponding receiver operation. Continuous Wave (CW) and Narrowband (or spot) noise tone jammers cause degradation to receiver SIR and degradation/denial of GPS navigation the same as wideband noise Effectiveness of such jamming techniques is greater than wideband noise as they lead to higher power spectral densities at receiver outputs, as they are highly concentrated signals in frequency domain. Narrowband anti-jamming techniques include adaptive filtering, time-frequency, adaptive antennas and subspace processing. The proposed system increases gain to desired signal and improves jamming rejection performance
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Research Journal of Applied Sciences, Engineering and Technology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
