Effect Of Jammer Research Articles

Evaluating the Effect of Jammer Radiation on Learning and Memory in Male Rats.

Previous studies shown that mobile phone can impairment of working memory in humans. In this study, the effect of radiofrequency radiation emitted from common mobile jammers have been studied on the learning and memory of rats. In this prospective study, 90 Sprague-Dawley rats, were divided into 9 groups (N=10): Control, Sham1st (exposed to a switched-off mobile jammer device at a distance of 50 or 100 cm/1 day, 2 hours), Sham2nd (similar to Sham1st, but for 14 days, 2 h/day), Experimental1st -50 cm/1 day &100 cm/1 day (exposed to a switched-on device at a distance of 50 or 100 cm for 2 hours), Experimental2nd (similar to experimental1st, but for 14 days, 2 h/day). The animals were tested for learning and memory the next day, by the shuttle box. The time that a rat took to enter the dark part was considered as memory. Mean short-term memory was shorter in the experimental- 50 cm/1 day than control and sham- 50 cm/1 day (P=0.034), long-term memory was similar. Mean short- and long-term memory were similar in the experimental- 100 cm/1 day, control and sham- 100 cm/1 day (P>0.05). Mean short-term memory was similar in experimental- 50 cm/14 days, control, and sham- 50 cm/14 days (P=0.087), but long-term learning memory was shorter in the radiated group (P=0.038). Mean short- and long-term were similar among experimental-100 cm/14 days, control or sham 100 cm/14 days (P>0.05). Rats exposed to jammer device showed dysfunction in short- and long-term memory, which shown the unfavorable effect of jammer on memory and learning. Our results indicated that the distance from radiation source was more important than the duration.

Performance of optical space shift keying under jamming.

In this paper, the effect of jamming in a free-space optical (FSO) communication system that employs optical space shift keying (OSSK) is studied. The optical link suffers from saturated atmospheric turbulence (AT). Hence, the channel fading coefficients follow negative exponential probability density function (PDF). Along with additive Gaussian noise, the jammer, under consideration, is an additional source of noise, and jamming signals also suffer from saturated AT. Thus, the jamming channel also follows the negative exponential PDF. A multiple-input single-output (MISO) FSO system is used to mitigate the effects of jammer and channel fading. Explicitly, we employ a 2×1 MISO-OSSK system for analysis and derive a closed-form expression of bit error rate (BER) of the considered system. Moreover, the jammer's effect is also studied numerically under the gamma-gamma (GG) fading channel.

Implementation and Assessment of Jamming Effectiveness Against an FMCW Tracking Radar Based on a Novel Criterion

The effect of jammer on radar or jamming performance has been and is being assessed on the basis of range reduction where consistency in tracking target ability is more important than range reduction in a tracking radar. A new criterion known as relative radar functionality destruction time is defined and introduced as the relative of functionality destruction time of radar to one period of jammer, where jammer signal and target echo power are of concern. The effective parameters in relative time of the receiver functioning destruction are assessed. Next, this criterion is applied in the assessment of simple conical scan radar receiver against a conventional jamming (sweep noise jamming). This criterion is modeled and simulated on a search radar in the jamming environment where the minimum required standard deviation of noise for destroying the radar function yields. By implementing the structure of a frequency modulated continuous wave tracking radar structure, a simple target based on digital radio frequency memory method and one type of jamming against this radar in a simultaneous manner, the functionality destruction is extracted for different radar parameters. This new criterion on outperforms its counterparts.

Autonomic Nervous System Disorder Due to Exposure RF Jamming

Background: The study of Heart rate is very important the body heart is directly related to heart rate ,the autonomic cardiovascular examination provides necessary information about function of the autonomic nervous system as well functional capacities of effectors heart and vessels and other associated part with radiation . Objective: To study the effect of jammer on autonomic nervous system as measured by heart rate. Patients and Methods: Heart rates of 10 males (age 21-51 years), and 10 females (age 20-54 years) were measured and recorded before, during using jammer for 15 minutes, 30 minutes, and 45 minutes, and one hour after shutting down the device . Results: The results clearly indicate that jammer radiation induced high fluctuations in heart rate variability of recovery period (after15 minutes using jammer) and show that the change of heart rate variability signal during jammer exposure is not permanent. There was no statistically significant difference observed in heart rate. Conclusion: The heart rate flection resulting from exposure to radiofrequencies of jammer are depending on the orientation of both electric &magnetic field of the electromagnetic radiation, the greater increase in heart rate that occurred during E orientation irradiation.

A Novel Cooperative Jamming Scheme for Wireless Social Networks Without Known CSI

Considering a wireless social network, we investigate a cooperative jamming scheme based on the space power synthesis with unknown channel state information (CSI) of eavesdroppers. In particular, we provide a multiple jammers-based anti-eavesdropping model and formulate it by a superposition principle of various jamming signals in a free space. Based on the model, we analyze the superimposed effects of jammers with different locations in a fixed area, and then present corresponding jamming schemes to minimize synthetic jamming power at a legitimate receiver but satisfying basic interference in other locations. Furthermore, we also provide power allocation schemes to maximize the worst-case secrecy rate of a legitimate receiver. Numerical simulation results demonstrate that the secrecy performance of our cooperative jamming schemes can satisfy the requirements of secure transmission in a fixed area. Besides, our proposed power allocation schemes can further improve secrecy rate without known exact CSI of eavesdroppers.

An analytical approach to the deployment quality of surveillance wireless sensor networks considering the effect of jammers and coverage holes

The requirements of surveillance wireless sensor networks, such as latency and reliability provisions, are directly related to the deployment quality, which is an indicator of the sensing capability of the network. The determination of the deployment quality is hindered by various factors that cause coverage holes, such as the existence of jammers and destruction of sensors. This paper presents an analytical deployment quality measure in terms of network parameters, including the sensor count, sensing coverage, coverage hole count, coverage hole area size and deployment area size. Assuming a random deployment model for both sensors and holes, our method determines the probability of detection of a target following a linear trajectory by a single sensor and generalizes it to derive the probability of detection in a network with coverage holes. The overall probability of detection is used as the network quality measure and is proposed as a suitable metric under sensor loss assumptions. The proposed deployment quality metric (DQM) is based on the shortest path strategy to provide a conservative estimation for the intruder detection performance. We show that it provides a good estimation of the actual deployment quality with given coverage hole and jamming area properties. Our metric is suitable for real life and simulation scenarios and is computationally inexpensive compared to both simulation based and distributed quality measurements.

Simulation of GPS and Galileo Architectures for Anti-jamming and Multipath Analysis

The launch of the new European satellite-positioning system named Galileo gives much potential for innovative developments such as hybrid architectures (e.g., combined GPS/Galileo receivers, new concepts like Software Defined Navigator). In this context, the use of a generic simulator proves to be essentially useful for signalprocessing analysis and for the design of new architectures of future multi-standard navigation receivers. The simulator proposed in this paper is developed on the basis of Matlab/Simulink ® software and makes possible the simulation of a completely digital architecture for GPS and Galileo receivers including the simulation of all sources of satellite signals and a generic channel of disturbances (e.g., multipath, Doppler, jammer, atmospheric delay, etc.) Moreover, the simulator is completely hierarchical allowing the user to handle all the sections in an interactive mode during the simulations. It should be mentioned that the simulator is very useful and effective for the analysis of multipath and jammer effects on the behavior of the PhaseLocked Loop (PLL) and Delay-Locked Loop (DLL) and for the evaluation of the performances of various precorrelation filters for the new generation of GPS/Galileo receivers. Particularly, the simulator considered in this paper allows for the analysis of Amplitude Domain Processing (ADP) and FADP (ADP in the frequency domain) filters to clarify their performances and complexity of implementations. This paper will briefly present the simulator and a generic demonstration concerning the use of the simulator. continued on page 14

Evaluation of sidelobe-canceller performance

A sidelobe canceller (SLC) can be efficiently employed to reduce the effects of jammers on a radar system. The paper deals with the evaluation of SLC performance, taking into account the estimation errors of the weighting coefficients of the auxiliary antennas. An explicit formula for the cancellation is given as a function of the ratio of the closed-loop bandwidth of the adaptive circuits and the radar receiver bandwidth, for one (single-sidelobe canceller, SSLC) auxiliary antenna and two (double-sidelobe canceller, DSLC) auxiliary antennas of the adaptive array and for one jammer. Therefore a relationship between the system adaption speed and the accuracy in the estimation of the jamming signal is obtained. A comparison is made between the performance of the two systems. From this analysis, a suitable selection of circuit parameters is suggested. Extensions are also made for any number of auxiliary antennas and for more than one jammer.

Single Sidelobe Canceller: Theory and Evaluation

A sidelobe canceller (SLC) can be efficiently employed to reduce the undesirable effects of jammers on a search radar system. In this paper a functional block circuit is described for a single-sidelobe canceller (SSLC) apt to a single Jammer suppression; a detailed analysis is also presented. It is shown that the theory of stochastic differential equations and the covariance analysis describing function (CADET) technique can be used to evaluate the SSLC performances when two Gaussian colored and mutually correlated input processes are considered. The statistical properties of the weight can be obtained. The last results, which are very important in the case of nonstationary jammers, cannot be obtained without this theory. System implications can be drawn from the abovementioned analysis when the input process consists of one jammer or two jammers and/or thermal noise.