This paper proposes a secure wireless system that integrates rate-splitting multiple access (RSMA), intelligent reflecting surfaces (IRS), and full-duplex relaying (FDR) to enhance secrecy performance against multiple colluding eavesdroppers. Closed-form expressions for the secrecy outage probabilities (SOPs) and average secrecy capacities (ASCs) of both common and private messages are derived. Comparative analysis with a baseline RSMA-FDR system (without IRS) demonstrates the benefits of IRS in improving secrecy. Numerical results reveal that RSMA-IRS-FDR achieves superior secrecy performance, with SOPs and ASCs strongly influenced by transmission power, particularly differing between message types. Moreover, the adverse effect of residual self-interference (RSI) is substantially mitigated in the IRS-aided system. The secrecy performance is further enhanced by increasing the number of IRS elements. The study also investigates the impact of key parameters such as power allocation, target secrecy rate, fading order, Wi-Fi frequency, and number of eavesdroppers, offering practical insights for secure RSMA-IRS-FDR system design.
This article proposes a combination of emerging technologies, including rate-splitting multiple access (RSMA), full-duplex (FD) communications, unmanned aerial vehicle (UAV) communications, intelligent reflecting surfaces (IRS), and millimeter-wave (mmWave) communications, to enhance the performance of wireless systems in fifth-generation (5G) and beyond (B5G) networks with multiple clusters. We mathematically derive and present formulas for outage probability (OP), throughput, and ergodic capacity (EC) for the proposed IRS-aided UAV-RSMA system with transmit antenna selection (TAS), employing FD transmission over Nakagami-m channels. Numerical results demonstrate that the proposed system offers significant performance improvements over existing systems. Specifically, across different comparative scenarios, TAS provides higher performance than systems without TAS. Furthermore, RSMA outperforms non-orthogonal multiple access (NOMA), particularly in high-power regions, by reducing OP and preventing error floor saturation. Additionally, increasing the number of reflecting elements (REs) substantially enhances system performance. Moreover, key factors such as carrier frequency, number of REs, transmission rates, UAV speed and altitude, and residual self-interference (SI) levels play a crucial role in minimizing OP and maximizing throughput and EC. Finally, Monte-Carlo simulations are conducted to validate the accuracy of the theoretical formulas.
This study addresses the core problem in Free-Space Optics (FSO): the misalignment of the laser beam and photodetector axes during signal transmission. Optimal parameters were determined for the plates in a developed beam steering system that employs an electro-optic mechanism, where control voltages modulate the refractive index of the optical material. The functional capabilities of the developed system for the precise alignment of the laser beam axis via the Pockels effect are described. The influence of plate temperature on the developed system performance of has been determined and compensation methods for thermal effects are proposed.
The article examines various temperature-monitoring systems based on optical fibers used under different conditions, enabling continuous temperature control in diverse media or objects. The operating principle of such systems relies on the change in the optical properties of the fiber material as temperature varies. Limitations that arise during long-term operation of existing sensors are highlighted. It is shown that when measuring temperature varying over wide ranges and across many zones, it becomes necessary to simplify the sensor design while maintaining accuracy. The use of optical fibers with a tapered core profile in fiber-optic sensor designs is proposed. A dependence is established between the variation of optical power losses of the detected signal and the temperature T to which the fiber is exposed. The obtained results make it possible to implement remote temperature monitoring using tapered fibers at distances exceeding 120 km from the laser source, photodetector module, and processing device. This significantly expands the applicability of remote temperature monitoring via optical fibers in open-air environments, for example, along power transmission lines.
The necessity of developing a simulator for testing the operation of blocks that generate sequences of control command codes, monitor various switching systems, and transmit measured environmental parameters and process them after transmission via an optical channel is justified. The design of a simulator using an air-optical communication channel for transmitting information in the form of a sequence of command codes is presented. The features of using a sequence of command codes when transmitting analog signals in an optical communication channel have been established. Confirmation has been obtained of the legitimacy of using the proposed method of forming analog optical signals for transmitting them over long distances.
