This paper deals with the problem of adaptive beamforming using a uniform linear array to provide multiple-beam constraints and suppress coherent jammers simultaneously. By constructing a steering matrix with each column vector corresponding to the steering vector of a selective beam and a constraint vector with each entry equal to the gain of a selective beam, we can achieve an adaptive array ...

Chaos-based communication systems are known to offer advantages that are shared by spread-spectrum communications. One important aspect of the performance of any spread-spectrum communication system is the ability to resist jamming. In this paper, an analysis of the antijamming performance of a coherent chaos shift keying system under the influence of a common pulsed-noise jammer is presented. ...

Jammers are the devices that disturb the communication in wireless networks. If the actual position of jammer is located then it is possible to eliminate the disturbances in communication networks. This project designs a framework to locate the position of a single or multiple jammers more accurately. Many present jammer localizing schemes use indirect methods considering the hearing ranges, pa...

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...

Wireless systems must be resilient to jamming attacks. Existing mitigation methods based on multi-antenna processing require knowledge of the jammer's transmit characteristics that may difficult acquire, especially for smart jammers evade by transmitting only at specific instants. We propose a novel method mitigate attacks massive multi-user multiple-input multiple-output (MU-MIMO) uplink which...

This paper presents a new algorithm named combination search strategy (CSS)-based improved particle swarm optimisation (IPSO) to address the resource allocation problem of multiple jammers. First, authors propose CSS effectively broaden limited range two-step solving framework. method not only simplifies solution framework but also considers combined relationship between beam pointing and trans...

As a tendency to use new technologies, gadgets such as laptop computers are becoming more popular among students, teachers, businessmen and office workers. Today laptops are a great tool for education and learning, work and personal multimedia. Millions of men, especially those in the reproductive age, are frequently using their laptop computers on the lap (thigh). Over the past several years, ...

Breast cancer is the most common malignancy among women, both in the developed and developing countries. Women with mutations in the BRCA1 and BRCA2 genes have an increased risk of breast and ovarian cancers. Recent studies show that short-wavelength visible light disturb the secretion of melatonin and causes circadian rhythm disruption. We have previously studied the health effects of exposure...