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1

Reliable 5G waveform detection from an optical fibre transmitter system

Yaseen Zeyad T., Algriree Waleed

Opto-Electronics Review

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2024

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Vol. 32, No. 1

art. no. e149181

EN

The integration of optical fibre communication with multiple input multiple output-non-orthogonal multiple access (MIMO-NOMA) waveforms in cognitive radio (CR) systems is examined in this study. The proposed system leverages the advantages of optical fibre, including high bandwidth and immunity to electromagnetic interference to facilitate the transmission and reception of MIMO-NOMA signals in a CR environment. Moreover, MIMO-NOMA signal was detected and analysed by the hybrid-discrete cosine transform-Welch (H-DCT-W) method. Based on the modes results, a detection probability greater than 0.96%, a false alarm probability equal to 0.06, and a global system error probability equal to 0.09% were obtained with a signal-to-noise ratio (SNR) less than 0 dB, while maintaining a simple level of complexity. The results obtained in this paper indicate the potential of the optical fibre-based MIMO-NOMA system based on H-DCT-W technology in CR networks. Therefore, its suitability for practical CR applications is demonstrated by the improvements obtained in false alarms, detection probability, and error rates at low levels of SNR. This study contributes to the development of efficient and reliable wireless communication systems by linking cooperation and synergy concerning MIMO-NOMA, optical fibres, as well as the proposed detection technique (H-DCT-W).

2

Proposed method for building an anti-drone system for the protection of facilities important for state security

Łukasiewicz Jędrzej, Kobaszyńska-Twardowska Anna

Security and Defence Quarterly

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2022

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Vol. 39, No. 3

88--107

EN

Unmanned aerial vehicles (UAVs) pose a threat to buildings and facilities important to the security of the state. As they are able to operate like individual aircraft, the number of ways they can be used for terrorist activity is practically unlimited. Anyone in charge of a facility that is crucial for the reliable functioning of a state is obliged to ensure an acceptable level of security. Since drones can be used to attack protected structures, they need to be protected by an anti-drone system. The paper proposes a method for assessing the effectiveness of systems for detecting and neutralising unmanned aerial vehicles. In order to suggest a new method for assessing the effectiveness of anti-drone systems, an analysis of the scientific literature and other documents describing existing anti-drone systems has been carried out. Attacks involving the use of drones, both in wartime and in incidents of terrorism, are also analysed and existing anti-drone solutions assessed. Because there are a variety of technical solutions for the detection and neutralisation of drones, and different location and weather conditions, a universal method is proposed based on probability calculations and neutralisation of drones, using mathematical formulas. This method allows for the effectiveness of the entire anti-drone system to be assessed on the basis of measuring the probability of detection and neutralisation of drones in real conditions. The proposed method allows the effectiveness of the currently existing anti-drone systems to be evaluated and for new methods for detecting and neutralising drones to be proposed. This method, based on mathematical calculations, enables software to be written for simulating anti-drone systems on computers and for the effectiveness of these systems to be confirmed before their construction in a protected facility.

3

Entropic upper bound for Bayes risk in the quantum case

Wieczorek R., Podsędkowska H.

Probability and Mathematical Statistics

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2018

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Vol. 38, Fasc. 2

429--440

EN

The entropic upper bound for Bayes risk in a general quantum case is presented. We obtained generalization of the entropic Lower bound for probability of detection. Our result indicates upper bound for Bayes risk (in a particular case of loss function – for probability of detection) in a pretty general setting of an arbitrary finite von Neumann algebra. It is also shown under which condition the indicated upper bound is achieved.

4

Theoretical Investigation of Diﬀerent Diversity Combining Techniques in Cognitive Radio

Agarwal R., Srivastava N., Katiyar H.

Journal of Telecommunications and Information Technology

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2018

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nr 3

64--69

EN

In this paper, the performance of an energy detector in cognitive radio, using diﬀerent diversity combining techniques, is evaluated. Among many diversity combining techniques, maximal ratio combining (MRC) gives the best results but at the cost of the highest complexity. To design a simpler receiver, it is suggested to use less complex combining techniques, i.e. switched diversity, which provides one of the least complex solutions to combat fading. The paper analyzes two switched diversity schemes, switch examine combining (SEC), and switch examine combining with post examining selection (SECp). A closed form expression determining the probability of detection using MRC, SEC and SECp is derived for various numbers of branches. Detection performance with diﬀerent diversity combining techniques is compared and the complexity trade-oﬀ is observed.

5

Passive infrared detector used for detection of very slowly moving of crawling people

Kastek M., Sosnowski T., Piątkowski T.

Opto-Electronics Review

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2008

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Vol. 16, No. 3

328-335

EN

The paper presents construction and principle of operation of passive IR detectors (PIR detectors) of a large detection range. Important virtue of these detectors is highly efficient detection of slowly moving or crawling people. The described here PIR detector detects crawling people at the distance of 140 m. To ensure high probability of detection of slowly moving objects, new method of signals analysis was applied. On the basis of the carried out real-time measurements, both probability of detection and false alarms were determined.