This letter studies the performance of the simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) aided non-orthogonal multiple access (NOMA) networks in support of ultra-reliable low-latency communications. We adopt effective capacity (EC) as the metric to explore the delay requirements of NOMA users. Specifically, the analytical expressions of the EC are obtained for the network with a pair of NOMA users on the different sides of the STAR-RIS. Furthermore, the high signal-to-noise ratio (SNR) slope and high SNR power offset are invoked to provide asymptotic analysis of the ECs in high SNR. Some insightful conclusions are drawn from the simulations: 1) the EC of near user $({U_{n}})$ increases linearly while the EC of far user $({U_{m}})$ tends to be a constant in the high SNR; 2) comparing with STAR-orthogonal multiple access and conventional RIS, the use of STAR-RIS NOMA increases the ECs of ${U_{n}}$ and overall network; 3) increasing the number of STAR-RIS elements is an effective strategy to improve the ECs of both ${U_{n}}$ and ${U_{m}}$ .

Industrial Internet of Things (IIoT) formation of richer ecosystem of intelligent interconnected devices while enabling new levels of digital innovation has essentially transformed and revolutionized global manufacturing and industry 4.0. Conversely, the prevalent distributed nature of IIoT, Industrial 5G, underlying IoT sensing devices, IT/OT convergence, Edge Computing, and Time Sensitive Networking makes it an impressive and potential target for cyber-attackers. Multi-variant persistent and sophisticated bot attacks are considered catastrophic for connects IIoTs. Besides, botnet attack detection is extremely complex and decisive. Thus, efficient and timely detection of IIoT botnets is a dire need of the day. We propose a hybrid intelligent Deep Learning (DL)-enabled mechanism to secure IIoT infrastructure from lethal and sophisticated multi-variant botnet attacks. The proposed mechanism has been rigorously evaluated with latest available dataset, standard and extended performance evaluation metrics, and current DL benchmark algorithms. Besides,cross validation of our results are also performed to clearly show overall performance. The proposed mechanisms outperforms in identifying accurately multi-variant sophisticated bot attacks. Besides, our proposed technique also show promising results in terms of speed efficiency.

The pinching-antenna architecture has emerged as a promising solution for reconfiguring wireless propagation environments and enhancing system performance. While prior research has primarily focused on sum-rate maximization or transmit power minimization of pinching-antenna systems, the critical aspect of energy efficiency (EE) has received limited attention. Given the increasing importance of EE in future wireless communication networks, this work investigates EE optimization in a non-orthogonal multiple access (NOMA)-assisted multi-user pinching-antenna uplink system. The problem entails the joint optimization of the users’ transmit power and the pinching-antenna position. The resulting optimization problem is non-convex due to tightly coupled variables. To tackle this, we employ an alternating optimization framework to decompose the original problem into two subproblems: one focusing on power allocation and the other on antenna positioning. A low-complexity optimal solution is derived for the power allocation subproblem, while the pinching-antenna positioning subproblem is addressed using a particle swarm optimization algorithm to obtain a high-quality near-optimal solution. Simulation results demonstrate that the proposed scheme significantly outperforms both conventional-antenna configurations and orthogonal multiple access-based pinching-antenna systems in terms of EE.

In this letter, we present a new approach of using time-modulated phased arrays to synthesize multicarrier directional modulation (DM) symbols for physical-layer security. In particular, the modulated waveform synthesis is achieved with the careful design of the switching time sequences, instead of in digital baseband; thus, reducing the peak-to-average power ratio of signals going through the radio frequency (RF) chain, and only a single RF chain is required here. The operation principle and synthesis approach are elaborated and demonstrated. In addition, the efficacy of the proposed DM approach is validated via the bit-error-rate (BER) metric.

Reconfigurable intelligent surface (RIS) is an electromagnetic surface, and has abundant low-power reflecting elements which can dynamically tune the wireless propagation environment by changing their phase shifts. Non-orthogonal multiple access (NOMA) technology would be capable of greatly improving the spectral efficiency of communication via differentiating users through power. Via integrating RIS into NOMA to improve wireless system performance, we take an uplink RIS-aided NOMA network with direct links into account, where multiple users communicate with the access point under the assistance of a RIS with multiple elements. We aim to obtain the maximum sum rate by optimizing the phase matrix of RIS subject to users’ transmitted power. Two algorithms are put forward to conquer the formulated intricate non-convex puzzle. More exactly, the semidefinite programming is proposed to relax the function while the majorization-minimization is used to derive the closed-form phase shifts. Finally, presented simulation results demonstrate the high performance of proposed schemes compared with no RIS and show the benefits of the existence of direct links.

The future sixth generation (6G) is going to face the significant challenges of massive connections and green communication. Recently, reconfigurable intelligent surfaces (RIS) and non-orthogonal multiple access (NOMA) have been proposed as two key technologies to solve the above problems. Motivated by this fact, we consider a downlink RIS-aided NOMA system, where the source aims to communicate with the two NOMA users via RIS. Considering future network supporting real-time service, we investigate the system performance with the view of effective capacity (EC), which is an important evaluation metric of delay sensitive systems. Specifically, we derive the analytical expressions of the EC of the near and far users. To obtain more useful insights, we deduce the analytical approximation expressions of the EC in the low signal-to-noise-ratio approximation by utilizing Taylor expansion. Moreover, we provide the results of orthogonal multiple access (OMA) for the purpose of comparison. It is found that (1) The number of RIS components and the transmission power of the source have important effects on the performance of the considered system; (2) Compared with OMA, NOMA system has higher EC due to the short transmission time.