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In this paper, we evaluate short packet communication (SPC) for a cooperative system where one relay assists data transmission between one multi-antenna source and one single antenna destination with the presence of co-channel interference at the relay. Two transmission schemes, i.e., transmit antenna selection (TAS) scheme and beamforming scheme (BF), are considered. Based on metric of SPC, we derive the average block error rate (BLER) for the system in asymptotic and closed-form expressions for both schemes. In addition, a solution of optimal power allocation (OPA) to maximize end-to-end effective system throughput is proposed. Effects of parameters such as total transmit power, number of the source’s antennas, number of co-channel interference, and packet length on the performance of the system are evaluated. Finally, the results reveal that the performance of the OPA scheme outperforms that of the benchmark scheme, i.e., equal power allocation solution, in terms of BLER and the effective throughput for both the TAS and BF schemes. Moreover, the performance of the system reaches to saturation value with more antennas at the source. The findings indicate that the TAS and BF schemes have the same performance in terms of both the BLER and the effective throughput.

ABSTRACTThe performance of broadcasting networks employing Fountain codes with receiver diversity techniques is investigated in the present work. Particularly, we derive the closed-form expressions of the cumulative distribution function (CDF), the probability mass function (PMF), and the raw moments of the number of the needed time slots to deliver a common message to all users under two diversity schemes, namely, maximal ratio combining (MRC) and selection combining (SC). Numerical results are supplied to verify the accuracy of the considered networks and highlight the behaviours of these metrics as a function of some vital parameters such as the number of receivers, and the number of received antennae. Additionally, we also confirm the advantages of the MRC scheme compared with the SC scheme in the broadcasting networks.

ABSTRACTThe performance of the simultaneous wireless information and power transfer (SWIPT) enabled full-duplex (FD) relaying in non-orthogonal multiple access (NOMA) networks is investigated in both reliability and security aspects. More precisely, for the viewpoint of reliability, we derive in the closed-form expression the outage probability (OP) at both end-users. On the other hand, intercept probability (IP) is considered a helpful metric to measure the security of the considered systems. Moreover, we derive the IP in the closed-form expression too. Numerical results are also given to confirm the correctness of the derived mathematical framework as well as to identify the insights of both metrics as a function of some key parameters such as the transmit power, the power-splitting (PS) ratio, and the power allocation ratio.

This paper studies the security and reliability of the power splitting (PS)-based relaying in the Internet of Things (IoT) networks with the help of a jammer. Based on the considered system model, we derive outage probability (OP) and intercept probability (IP) under two distinguished schemes, namely, the static PS relaying (SPSR) scheme and the dynamic PS relaying (DPSR) scheme. More precisely, the PS ratio of the former is a constant number, while the latter is optimally adjusted in order to minimize the OP and counts only on the channel gain of the second hop. Numerical results are provided to not only verify the accuracy of the proposed mathematical framework but also identify the trends of both OP and IP with respect to several important parameters. Our findings unveil that the OP and IP have contradictory behavior with respect to the transmit power and number of sources. Moreover, the performance of the DPSR scheme is superior to that of the SPSR scheme.

This paper investigates the security–reliability of simultaneous wireless information and power transfer (SWIPT)-assisted amplify-and-forward (AF) full-duplex (FD) relay networks. In practice, an AF-FD relay harvests energy from the source (S) using the power-splitting (PS) protocol. We propose an analysis of the related reliability and security by deriving closed-form formulas for outage probability (OP) and intercept probability (IP). The next contribution of this research is an asymptotic analysis of OP and IP, which was generated to obtain more insight into important system parameters. We validate the analytical formulas and analyze the impact on the key system parameters using Monte Carlo simulations. Finally, we propose a deep learning network (DNN) with minimal computation complexity and great accuracy for OP and IP predictions. The effects of the system’s primary parameters on OP and IP are examined and described, along with the numerical data.

Outage probability (OP) and potential throughput (PT) of multihop full-duplex (FD) nonorthogonal multiple access (NOMA) systems are addressed in the present paper. More precisely, two metrics are derived in the closed-form expressions under the impact of both imperfect successive interference cancellation (SIC) and imperfect self-interference cancellation. Moreover, to model short transmission distance from the transmit and receive antennae at relays, the near-field path-loss is taken into consideration. Additionally, the impact of the total transmit power on the performance of these metrics is rigorously derived. Furthermore, the mathematical framework of the baseline systems is provided too. Computer-based simulations via the Monte Carlo method are given to verify the accuracy of the proposed framework, confirm our findings, and highlight the benefits of the proposed systems compared with the baseline one.

In the trade centre, there are always unannounced emergencies that need to be addressed to maintain order. Therefore, a smart system is required to detect threats and deal with them. In this paper, we propose a secure network system that is structured into three layers including Unmanned Aerial Vehicle (UAV) devices, self-acting robots, and sensor networks. The system operates in two directions: 1) The sensor network tracks the environment and provides raw data to the robots, from here will be transmitted directly to the storage and processing centre or the nearest UAV devices and 2) the administrator or operation centre gives operational instructions to the UAV devices. Based on the analysis of the environmental data on the cloud server, the proposed system can automatically generate warnings and actions in time.

In this paper, a low-profile and broadband array antenna is proposed for satellite downlink applications. The proposed antenna is comprised of 4 × 4 elements, which are yielded for the downlink of the C band from 3.7 to 4.8 GHz. By arranging frequency selective surface (FSS) unit cells according to a new architecture, high directivity and broadband are provided, in which each element is covered by a lattice of 3 × 3 periodic metal plates. Based on RO4350B, the final design with a total size of 180 × 180 × 3.175 mm3 (2.38λ × 2.38λ × 0.04λ at the lowest frequency of 3.97 GHz) has been fabricated, measured, and witnessed a broadband characteristic with S11 < −10 dB of 36% (3.97–5.5 GHz). In addition, the proposed antenna achieves a peak gain of 16 dBi and a radiation efficiency of 71%. [ABSTRACT FROM AUTHOR]

Visual surveillance systems have been playing an important role in monitoring and managing at public areas. However, the computational complexity of video compression in these applications is still a great challenge. To meet practical requirements, the authors propose in this paper a low‐complexity surveillance video coding solution in which the most recent Versatile Video Coding (VVC) standard is improved with a novel learning adaptive motion search algorithm. The proposed algorithm is designed based on the temporal motion and spatial texture characteristics of surveillance videos. First, the authors study and define a list of spatial and temporal features which indicates the motion and texture characteristics of surveillance video. These features are used together with a machine learning algorithm to appropriately assign a search range for the VVC motion search. Second, to reduce search points, the authors propose an adaptive Test Zone (TZ) search in which TZ steps are early terminated following the variation of spatial–temporal features. Performance evaluation conducted for a rich set of surveillance videos and relevant benchmarks have shown the superiority of the proposed method, notably with around 33% of encoding time saving when compared with the state‐of‐the art VVC solution and relevant benchmarks while asking for negligible compression loss. [ABSTRACT FROM AUTHOR]

The comprehensive performance of cognitive broadcasting networks employing Fountain codes (FC) and maximal ratio transmission (MRT) is investigated in the present paper. More precisely, the secondary transmitter (ST) employs Fountain code to effectively broadcast a common message such as a safety warning, security news, etc., to all secondary receivers (SRs) via underlay protocol of cognitive radio networks (CRNs). Different from works in the literature that are interested in studying the outage probability (OP), and the ergodic capacity of the CRNs. The present paper, on the other hand, focuses on the characteristics of the number of needed time slots to successfully deliver such a message. Particularly, we derive in closed-form expressions the cumulative distribution function (CDF), the probability mass function (PMF), and the average number of the required time slot to broadcast the message to all SRs. Additionally, we also provide the throughput of secondary networks (SNs). We point out the impact of some key parameters, i.e., the number of SRs and the number of transmit antennae at the secondary transmitter, on the performance of these considered metrics. Numerical results via the MonteCarlo method are given to verify the accuracy of the derived framework as well as to highlight the influences of some essential parameters. Furthermore, we also compare the performance of the proposed networks with state-of-the-art and simulation results unveiling that the considered system consistently outperforms works in the literature. [ABSTRACT FROM AUTHOR]

At the design calculation phase, the seismic analysis of a nuclear building is usually based on the assumption of structural linearity. Moreover, design codes impose to consider three-component ground motions. In this context, the response spectrum method is likely the most used seismic design approach. Different variants of the response spectrum method exist, the main differences among them being related to the way of superposing the contributions of the three ground motion components and to the treatment of the simultaneity of physically distinct responses. A set of nr ≥ 2 simultaneous values of distinct responses can be called response vector. The basic variants of the response spectrum method provide the peak value of each distinct response, allowing the definition of a parallelepiped envelope for the response vectors: this envelope is conservative since the peaks of distinct responses, in general, do not occur simultaneously. Conversely, the so-called elliptical response envelopes, which are hyper-ellipsoids of dimension nr, correctly take into account response simultaneity. In the first part of this paper, a new interpretation of the response envelopes is presented, based on the notion of probable linear combinations of modes. The practical use of response envelopes is not straightforward when nr > 3, like e.g. in the case of shell finite elements with three membrane forces and three moments. A standard procedure consists in approximating the response envelope by an enveloping polyhedron, whose vertices define a set of response vectors. The definition of a refined polyhedron, closer to the surface of the response envelope, is proposed in the second part of the paper. Another commonly used approach for the seismic structural design is the so-called equivalent static method, where the seismic action is represented by a static force field applied to the structure. The main difficulty in the practical application of this method is the definition of a static force field taking into account all the ground motion components and the contribution of all the structural modes. A novel procedure for the definition of equivalent static loads is described in the third part of this article, based on the use of pseudo-inertia forces and on the notion of probable linear combinations of modes. In the last part of the paper, both the response envelope approach and the proposed procedure for the equivalent static load definition are applied to the seismic design of a representative reinforced concrete nuclear building. The results are compared with those obtained by several classical variants of the response spectrum method. [ABSTRACT FROM AUTHOR]

We design and test a shape memory alloy (SMA)-based actuation system that can be used to propel a fish robot. The actuator in the system is composed of a 0.1 mm diameter SMA wire, a 0.5 mm-thick glass/epoxy composite strip, and a fixture frame. The SMA wire is installed in a pre-bent composite strip that provides initial tension to the SMA wire. The actuator can produce a blocking force of about 200 gram force (gf) and displacement of 3.5 mm at the center of the glass/epoxy strip for an 8 V application. The bending motion of the actuator is converted into the tail-beat motion of a fish robot through a linkage system. The fish robot is evaluated by measuring the tail-beat angle, swimming speed, and thrust produced by the tail-beat motion. The tail-beat angle is about 20 the maximum swimming speed is about 1.6 cm/s, and the measured average thrust is about 0.4 gf when the fish robot is operated at 0.9 Hz. [ABSTRACT FROM AUTHOR]

The performance of the satellite-terrestrial network with Fountain codes (FCs) is conducted in the present work. More precisely, the air-to-ground link is modeled according to the shadow-Rician distribution to capture the strong light-of-sight (LOS) path as well as the impact of the shadowing. As a result, we employ the directional beamforming at both the satellite and relay to mitigate such an ultra-long transmission distance. We investigate the trade-off between the reliability and security aspects. Particularly, we derive the outage probability (OP) and intercept probability (IP) in the closed-form expressions. To further facilitate the security of the considered networks, the friendly jamming scheme is deployed as well. Finally, simulation results based on the Monte-Carlo method are given to corroborate the exactness of the developed mathematical framework and to identify key parameters such as antenna gain, and transmit power that have a big impact on the considered networks.