This study proposes an anti-jamming scheme for linear frequency modulated (LFM) radars to combat smart noise jamming, which is a newly proposed pattern that is very effective against LFM radars. First, by utilizing the smeared spectrum technique, the chirp rates of the target return and jamming signal can be changed. The target return and jamming signal then exhibit different characteristics af...

Cognitive Radio promises to be a solution for the spectrum underutilization problems. However, security issues pertaining to Cognitive Radio technology are still an understudied topic. One of the prevailing such issues are intelligent radio frequency jamming attacks, where adversaries are able to exploit on-the-fly reconfigurability potentials and learning mechanisms of Cognitive Radios in orde...

Wireless local area networks (WLANs) can adopt channel hopping technologies in order to avoid unintentional interferences such as radars or microwaves, which function as proactive jamming signals. Even though channel hopping technologies are effective against proactive types of jamming, it has been reported that reactive jammers could attack the targets through scanning busy channels. In this p...

This paper studies the impact of GPS jamming on GPS carrier-phase time transfer. To study this issue, at NIST, we have installed a commercial GPS jamming detector since 2014 April. During 2014 April – 2015 April, the detector detected more than 100 jamming events, though there had been a few outages of jamming detection. The jamming events usually last for less than 2 min. We find that almost a...

We deal with the difficulty of jamming under an interior risk representation. We present a challenger model of choose jamming attacks, and also define packet delivery techniques in which specific messages of “high importance” are targeted. Jamming attacks can severely interfere with the normal operation of wireless networks and, consequently, mechanisms are needed that can cope with jamming att...

Jamming has traditionally been studied as a mechanical phenomenon and characterized with mechanical order parameters. However, this approach is not meaningful in the "mechanical vacuum" of systems below jamming in which all mechanical properties are precisely zero. We find that the network of nearest neighbors and the geometric structure of the Voronoi cell contain well-defined and meaningful o...

This letter investigates the problem of anti-jamming communications in dynamic and unknown environment through on-line learning. Different from existing studies which need to know (estimate) the jamming patterns and parameters, we use the spectrum waterfall, i.e., the raw spectrum environment, directly. Firstly, to cope with the challenge of infinite state of raw spectrum information, a deep an...

Interference detection is very important for Global Navigation Satellite System (GNSS) receivers. Current work on interference detection in GNSS receivers has mainly focused on time-frequency (TF) analysis techniques, such as spectrogram and Wigner-Ville distribution (WVD), where the spectrogram approach presents the TF resolution trade-off problem, since the analysis window is used, and the WV...

The echolocation behavior of Pipistrellus abramus during exposure to artificial jamming sounds during flight was investigated. Echolocation pulses emitted by the bats were recorded using a telemetry microphone mounted on the bats' backs, and their adaptation based on acoustic characteristics of emitted pulses was assessed in terms of jamming-avoidance responses (JARs). In experiment 1, frequenc...

This is Part I of a two-part paper that considers antijamming system design in wireless networks based on messagedriven frequency hopping (MDFH), a highly efficient spread spectrum technique. In this paper, we first analyze the performance of MDFH under hostile jamming. It is observed that while MDFH is robust under strong jamming, it experiences considerable performance losses under disguised ...