We numerically produce fully amorphous assemblies of frictionless spheres in three dimensions and study the jamming transition these packings undergo at large volume fractions. We specify four protocols yielding a critical value for the jamming volume fraction which is sharply defined in the limit of large system size, but is different for each protocol. Thus, we directly establish the existenc...

A distributed multiuser two-way amplify-and-forward (AF) wireless relay strategy consisting of 2M sources (or 2M destinations) and N relays all equipped with single antenna per communication node is studied in this paper. All sources act as both sources and destinations with a self-interference cancelation process at the 2M destinations. The main objective is to design the closed-form of minimu...

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Interrupted sampling repeater jamming (ISRJ) is an effective coherent jamming, which can induce false high-resolution range profile (HRRP) and image to greatly complicate the target detection and recognition of wideband radar. To counter ISRJ, an efficient filter is designed based on the time-frequency (TF) characteristic differences between target echo and ISRJ. Meanwhile, a feasible jamming s...

The role of the friction coefficient, m, on the jamming properties of disordered, particle packings is studied using computer simulations. Compressed, soft-sphere packings are brought towards the jamming transition—the point where a packing loses mechanical stability—by decreasing the packing fraction. The values of the packing fraction at the jamming transition, fmc, gradually decrease from th...

WiMAX is at the peak of communication technology as it is gaining a great position in the next generation of wireless networks. With the development of various wireless networks rapidly, they have turn into necessary infrastructure in our networking atmosphere. The main challenge for WiMAX is the problems associated with various jamming attacks that make them unavailable. Jamming attack is easy...

This letter introduces the concept of antifragile electronic warfare (EW), which we define as the ability to allow a communications link to improve performance due to the presence of a jammer. This concept should not be confused with jamming countermeasures (a.k.a. anti-jamming or electronic protection). Rather, antifragile EW can be thought of as the next step beyond simply avoiding or mitigat...

It is knownlhat partial-band tone jamming (PBTJ) is generally the worst form of jamming for frequency-hopped M-ary FSK (FH/MFSK) communication systems. Recent studies show that for some coded systems, full-band noise jamming (FBNJ) is more effective than worst-case PBTJ if a receiver is able to utilize jamming state information (JSI) for decoding, when the symbol energy-to-uniform noise jamming...

Currently deployed WLAN network use cooperative spectrum sharing and is prone to jamming based denial of service attack. In this article we propose a model to avoid jamming that use decentralized channel hopping algorithm. Upon detection of jamming, the network switches its channel of operation in accordance with pseudo-random sequence based rendezvous. We develop a testbed to evaluate the feas...

An analytical study is presented for the performance of fast frequency-hopping (FFH) self-normalized orthogonal -ary frequency-shift-keyed (MFSK) noncoherent receivers in the presence of multitone jamming. The multiple equal-power jamming tones are assumed to correspond to some of the possible FFH/ -ary orthogonal signaling tones. It has been shown that a higher diversity order (the number of h...