In the present work we deal with the concept of jamming with incomplete information about the jammer. We consider two scenarios. In the first one a jammer could be either present in the environment bringing extra background noise or absent. The user has only statistical knowledge about either presence or absence of the jammer. Namely, the user knows that in the environment only a natural backgr...

Jamming is one of the most severe attacks in wireless sensor networks (WSNs). While existing countermeasures mainly focus on designing new communication mechanisms to survive under jamming, a proactive solution is to first localize the jammer(s) and then take necessary actions. Unlike the existing work that focuses on localizing a single jammer in WSNs, this work solves a multi-jammer localizat...

different methods exists for jamming mitigation and we should choose a method based an the jammer type and other parameters. one of the jammers is narrow band fm jammer and we use subspace projection techniques for the suppression of this type of jammer. in subspace projection technique, we estimate the if of signals and construct the subspace vector that is orthogonal to jammer vector by incre...

It is often assumed in system analyses that a partial-band noise jammer against a frequency-hopped M-ary frequency shift keying (FHMFSK) communication system has a rectangular spectrum. The rectangular spectrum is, of course, unrealizable, and so it is of interest to consider more realistic spectrums, such as those where a jammer uses a bandpass filter before amplifying the jamming noise. In th...

After being modulated by a periodic signal, the pulse compression result of the modulated LFM (Linear Frequency Modulation) may have many isolated and sharp peaks. According to this phenomenon, we developed a strip-map SAR (Synthetic Aperture Radar) jammer which modulated both the SAR’s fast and slow time LFMs with periodic waveforms. This kind of jamming can forge isolated and bright points in...

The present work concerns a system aimed at enhancing a target talker under varying signal conditions based on the use of several di erent types of information or \cues". Toward this end, an architecture designed to combine separately operating estimators is described and evaluated. The architecture is currently implemented using spatialand periodicitybased enhancement algorithms, and evaluated...

We study the performance of the IEEE 802.11 MAC protocol under a range of jammers that covers both channel-oblivious and channel-aware jamming. We consider two channel-oblivious jammers: a periodic jammer that jams deterministically at a specified rate, and a memoryless jammer whose interfering signals arrive according to a Poisson process. We also develop new models for channel-aware jamming, ...

INTRODUCTION The rapid growth of wireless communication technologies has caused public concerns regarding the biological effects of electromagnetic radiations on human health. Some early reports indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians such as the alterations of the pattern of muscle extractions. This study is aimed at investigating the effects ...

This letter proposes a novel UAV-enabled mobile jamming scheme to improve the secrecy rate of ground wiretap channel. Specifically, a UAV is employed to transmit jamming signals to combat against eavesdropping. Such a mobile jamming scheme is particularly appealing since the UAV-enabled jammer can fly close to the eavesdropper and opportunistically jam it by leveraging the UAV’s mobility. We ai...