Millimeter-wave (mmWave) communication is regarded as the key enabling component for fifth-generation (5G) cellular systems due to the large available spectrum bandwidth. To make mmWave new radio (NR) a reality, tremendous efforts have been exerted from the industry and academia. Performance evaluation of mmWave NR is a mandatory step and the key to ensuring the success of mmWave 5G deployment. Over-the-air

An ultra-massive phased array can be deployed in high-throughput millimeter-wave (mmWave) communication systems to increase the transmission distance. However, when the signal bandwidth is large, the antenna array response changes with the frequency, causing beam squint. In this paper, we investigate the beam squint effect on a high-throughput mmWave communication system with the single-carrier frequency-domain

毫米波天线设计面临高增益、宽带、低成本等诸多挑战,在该频段基片集成波导(Substrate Integrated Waveguide,SIW)由于其辐射损耗低和易集成的优势而被广泛应用。然而在毫米波频段SIW的介质损耗直接降低了天线辐射效率,若采用低损耗介质材料会导致较高的制造成本。基片集成空腔波导(Empty Substrate Integrated Waveguide,ESIW)结构通过去除SIW中介质,可实现电磁波低损耗传输,在毫米波频段具有广阔应用前景。本文面向5G n260频段应用,提出一款采用低成本FR-4 PCB板材设计的缝隙天线阵。天线采用基片集成空腔波导结构设计,消除了介质损耗,并引入高次模腔体结构,减小馈电网络复杂度,在保证天线性能前提下,实现了毫米波天线低成本制造,为低成本毫米波天线设计提供了技术参考。 天线由5层FR-4 PCB板组成,从顶层往下依次为缝隙辐射层、高

As the fifth-generation (5G) mobile communication system is being commercialized, extensive studies on the evolution of 5G and sixth-generation (6G) mobile communication systems have been conducted. Future mobile communication systems are evidently evolving toward a more intelligent and software-reconfigurable functionality paradigm that can provide ubiquitous communication, as well as sense, control

Millimeter-wave (mmWave) technology has been well studied for both outdoor long-distance transmission and indoor short-range communication. In the recently emerging fiber-to-the-room (FTTR) architecture in the home network of the fifth generation fixed networks (F5G), mmWave technology can be cascaded well to a new optical network terminal in the room to enable extremely high data rate communication

In this study, we consider a multi-cell millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) system with a mixed analog-to-digital converter (mixed-ADC) and hybrid beamforming architecture, in which antenna selection is applied to achieve intelligent assignment of high- and low-resolution ADCs. Both exact and approximate closed-form expressions for the uplink achievable rate are derived

In recent years, the conventional degrees of freedom in frequency and time have been fully used. It is difficult to further improve the performance of communication systems with such degrees of freedom. Orbital angular momentum (OAM), which provides a new degree of freedom for millimeter-wave (mmWave) wireless communication systems, has been recognized as a key enabling technique for future mobile

The deployment of millimeter-wave (mmWave) cellular systems in dense urban environments with an acceptable coverage and cost-efficient transmission scheme is essential for the rollout of fifth-generation and beyond technology. In this paper, cluster-based analysis of mmWave channel characteristics in two typical dense urban environments is performed. First, radio propagation measurement campaigns are

With the increased demand for unmanned driving technology and big-data transmission between vehicles, millimeter-wave (mmWave) technology, due to its characteristics of large bandwidth and low latency, is considered to be the key technology in future vehicular communication systems. Different from traditional cellular communication, the vehicular communication environment has the characteristics of

Orthogonal time frequency space (OTFS) modulation has been widely considered for high-mobility scenarios. Satellite-to-ground communications have recently received much attention as a typical high-mobility scenario and face great challenges due to the high Doppler shift. To enable reliable communications and high spectral efficiency in satellite mobile communications, we evaluate OTFS modulation performance

A 9.8–30.1 GHz CMOS low-noise amplifier (LNA) with a 3.2-dB minimum noise figure (NF) is presented. At the architecture level, a topology based on common-gate (CG) cascading with a common-source (CS) amplifier is proposed for simultaneous wideband input matching and relatively high gain. At the circuit level, multiple techniques are proposed to improve LNA performance. First, in the CG stage, loading

We introduce a dual-polarized (DP) Fabry—Pérot cavity (FPC) antenna operating at the millimeter-wave (mmWave) frequency band with high-gain and wideband characteristics. A DP feeding source and a partially reflective surface (PRS) integrated with a Fresnel zone lens are suggested to realize dual-polarization wave radiation over a wide impedance bandwidth. The feeding source provides vertical and horizontal

Gait recognition has significant potential for remote human identification, but it is easily influenced by identity-unrelated factors such as clothing, carrying conditions, and view angles. Many gait templates have been presented that can effectively represent gait features. Each gait template has its advantages and can represent different prominent information. In this paper, gait template fusion

In this study, titanium disulfide (TiS2) polyvinyl alcohol (PVA) film-type saturable absorber (SA) is synthesized with a modulation depth of 5.08% and a saturable intensity of 10.62 MW/cm2 by liquid-phase exfoliation and spin-coating methods. Since TiS2-based SA has a strong nonlinear saturable absorption property, two types of optical soliton were observed in a mode-locked Er-doped fiber laser. When

The Shack-Hartmann wavefront sensor (SHWS) is an essential tool for wavefront sensing in adaptive optical microscopes. However, the distorted spots induced by the complex wavefront challenge its detection performance. Here, we propose a deep learning based wavefront detection method which combines point spread function image based Zernike coefficient estimation and wavefront stitching. Rather than

A set of semiconductor laser pulse seed sources based on an embedded chip is proposed. The greatest feature is that the optical pulse frequency and width can be independently adjusted in real time. The pulse seed sources can be switched independently and online from the gain-switched mode to the quasi-continuous wave mode to obtain optimal optical parameters for specific applications. To explore the

This paper presents an empirical study of the uplink and downlink azimuth angle of arrival (AoA) in an urban micro (UMi) scenario at 28 GHz. At present, most UMi measurements are conducted in the downlink and then the uplink situation is inferred assuming channel reciprocity. Although the channel correlation coefficient of the uplink and downlink can be as high as 0.8, this does not mean that they

We study the exfoliation of ultrathin ReS2 nanosheets from the prepared ReS2 powder and their application to Q-switched Er-doped fiber laser. XRD, Raman, and XPS spectra confirm the successful preparation of the layered ReS2. SEM images show that the obtained ReS2 sheets have lateral size below 200 nm. The thickness of the ReS2 nanosheets is smaller than 5 nm according to the AFM results. ReS2/PVA

Script is the structured knowledge representation of prototypical real-life event sequences. Learning the commonsense knowledge inside the script can be helpful for machines in understanding natural language and drawing commonsensible inferences. Script learning is an interesting and promising research direction, in which a trained script learning system can process narrative texts to capture script

With technological advancements, weapon system development has become increasingly complex and costly. Using modeling and simulation (M&S) technology in the conceptual design stage is effective in reducing the development time and cost of weapons. One way to reduce the complexity and trial-and-error associated with weapon development using M&S technology is to develop combat scenarios to review the

Topological insulator Sb2Te3 has the advantage of broadband saturable absorption from the visible to the infrared bands. Herein, the two-dimensional material Sb2Te3 saturable absorber (SA) of the topological insulator family was first applied experimentally in a wideband tunable passively Q-switched Yb-doped fiber laser. High-quality Sb2Te3 crystals were synthesized by the flux zone method. The Sb2Te3

Traditional diagnosis of attention deficit hyperactivity disorder (ADHD) in children is primarily through a questionnaire filled out by parents/teachers and clinical observations by doctors. It is inefficient and heavily depends on the doctor’s level of experience. In this paper, we integrate artificial intelligence (AI) technology into a software-hardware coordinated system to make ADHD diagnosis

Service composition is an effective method of combining existing atomic services into a value-added service based on cost and quality of service (QoS). To meet the diverse needs of users and to offer pricing services based on QoS, we propose a service composition auction mechanism based on user preferences, which is strategy-proof and can be beneficial in selecting services based on user preferences

While the Nyquist rate serves as a lower bound to sample a general bandlimited signal with no information loss, the sub-Nyquist rate may also be sufficient for sampling and recovering signals under certain circumstances. Previous works on sub-Nyquist sampling achieved dimensionality reduction mainly by transforming the signal in certain ways. However, the underlying structure of the sub-Nyquist sampled

As an increasingly popular flow metering technology, Coriolis mass flowmeter exhibits high measurement accuracy under single-phase flow condition and is widely used in the industry. However, under complex flow conditions, such as two-phase flow, the measurement accuracy is greatly decreased due to various factors including improper signal processing methods. In this study, three digital signal processing

We propose a novel indoor positioning algorithm based on the received signal strength (RSS) fingerprint. The proposed algorithm can be divided into three steps, an offline phase at which an advanced clustering (AC) strategy is used, an online phase of approximate localization at which cluster matching is used, and an online phase of precise localization with kernel ridge regression. Specifically, after

Online social networks have attracted great attention recently, because they make it easy to build social connections for people all over the world. However, the observed structure of an online social network is always the aggregation of multiple social relationships. Thus, it is of great importance for real-world networks to reconstruct the full network structure using limited observations. The multiplex

We demonstrate the generation of noise-like pulses (NLPs) and soliton rains in a graphene saturable absorber mode-locked erbium-doped fiber laser. Typical NLPs are obtained at a proper pump power and in a cavity polarization state. The soliton rain operation with multiple solitons can be achieved by finely adjusting the cavity polarization state. In addition, distinctive multi-soliton interactions

Extracting discriminative speaker-specific representations from speech signals and transforming them into fixed length vectors are key steps in speaker identification and verification systems. In this study, we propose a latent discriminative representation learning method for speaker recognition. We mean that the learned representations in this study are not only discriminative but also relevant.

Indium selenide (InSe) is a typical layered metal-chalcogenide semiconductor that has potential for developing ultrafast optoelectronic devices. In this work, InSe-polyvinyl alcohol (InSe-PVA) film is employed as saturable absorber and prepared by mixing InSe nanosheets solution and polyvinyl alcohol solution. The nonlinear absorption properties of the InSe saturable absorber (InSe-SA) are investigated

To maximize signal collection in nonlinear optical microscopy, non-descanned epi-detection is generally adopted for in vivo imaging. However, because of severe scattering in biological samples, most of the emitted fluorescence photons go beyond the collection angles of objectives and thus cannot be detected. Here, we propose an extended detection scheme to enhance the collection of scattered photons

Estimating the target position of low-frequency sound sources in a shallow sea environment is difficult due to the high cost of hydrophone placement and the complexity of the propagation model. We propose a compressed recurrent neural network (C-RNN) model that compresses the signal received by a vector hydrophone into a dynamic sound intensity signal and compresses the target position of the sound

Tagging is a defining characteristic of Web 2.0. It allows users of social computing systems (e.g., question and answering (Q&A) sites) to use free terms to annotate content. However, is tagging really a free action? Existing work has shown that users can develop implicit consensus about what tags best describe the content in an online community. However, there has been no work studying the regularities

In this study, we provide an overview of recent advances in multisensor multitarget tracking based on the random finite set (RFS) approach. The fusion that plays a fundamental role in multisensor filtering is classified into data-level multitarget measurement fusion and estimate-level multitarget density fusion, which share and fuse local measurements and posterior densities between sensors, respectively

We study how to achieve the state consensus of a whole multi-agent system after adding some new agent groups dynamically in the original multi-agent system. We analyze the feasibility of dynamically adding agent groups under different forms of network topologies that are currently common, and obtain four feasible schemes in theory, including one scheme that is the best in actual industrial production

This paper presents the design of a new event-triggered Kalman consensus filter (ET-KCF) algorithm for use over a wireless sensor network (WSN). This algorithm is based on information freshness, which is calculated as the age of information (AoI) of the sampled data. The proposed algorithm integrates the traditional event-triggered mechanism, information freshness calculation method, and Kalman consensus

The economic dispatch problem of a smart grid under vicious denial of service (DoS) is the main focus of this paper. Taking the actual situation of power generation as a starting point, a new distributed optimization model is established which takes the environmental pollution penalty into account. For saving the limited bandwidth, a novel distributed event-triggered scheme is proposed to keep the

Designing an efficient distributed economic dispatch (DED) strategy for the smart grid (SG) in the presence of multiple generators plays a paramount role in obtaining various benefits of a new generation power system, such as easy implementation, low maintenance cost, high energy efficiency, and strong robustness against uncertainties. It has drawn a lot of interest from a wide variety of scientific

An algorithm is presented for leader-following synchronization of a multi-agent system composed of linear agents with time delay. The presence of different delays in various agents can cause a synchronization error that does not converge to zero. However, the norm of this error can be bounded and this boundary is presented. The proof of the main results is formulated by means of linear matrix inequalities

In this study, the finite-time formation control of multi-agent systems with region constraints is studied. Multiple agents have first-order dynamics and a common target area. A novel control algorithm is proposed using local information and interaction. If the communication graph is undirected and connected and the desired framework is rigid, it is proved that the controller can be used to solve the

In this study, we extend traditional (single-target) hybrid systems to multi-target hybrid systems with a focus on the multi-maneuvering-target tracking system. This system consists of a continuous state, a discrete and switchable state, and a discrete, time-constant, and unique state. By defining a new generalized labeled multi-Bernoulli density, we prove that it is closed under the Chapman-Kolmogorov

This study deals with constant-gain adaptive observers for nonlinear systems, for which relatively few solutions are available for some particular cases. We introduce an asymptotic observer of constant gain for nonlinear systems that have linear input. This allows the observer design to be formulated within the linear matrix inequality paradigm provided that a strictly positive real condition between

In this study, we present the convergence of time-varying networks. Then, we apply the convergence property to cooperative control of nonlinear multiagent systems (MASs) with unknown control directions (UCDs), and illustrate a new kind of Nussbaum-type function based control algorithms. It is proven that if the time-varying networks are cut-balance, the convergence of nonlinear MASs with nonidentical

In an unmanned aerial vehicle ad-hoc network (UANET), sparse and rapidly mobile unmanned aerial vehicles (UAVs)/nodes can dynamically change the UANET topology. This may lead to UANET service performance issues. In this study, for planning rapidly changing UAV swarms, we propose a dynamic value iteration network (DVIN) model trained using the episodic Q-learning method with the connection information

We present a novel indirect adaptive fuzzy-regulated optimal control scheme for continuous-time nonlinear systems with unknown dynamics, mismatches, and disturbances. Initially, the Hamilton-Jacobi-Bellman (HJB) equation associated with its performance function is derived for the original nonlinear systems. Unlike existing adaptive dynamic programming (ADP) approaches, this scheme uses a special non-quadratic

A 0.20–2.43 GHz fractional-N frequency synthesizer is presented for multi-band wireless communication systems, in which the scheme adopts low phase noise voltage-controlled oscillators (VCOs) and a charge pump (CP) with reduced current mismatch. VCOs that determine the out-band phase noise of a phase-locked loop (PLL) based frequency synthesizer are optimized using an automatic amplitude control technique

We deal with event-triggered H∞ controller design for discrete-time piecewise-affine systems subject to actuator saturation. By considering saturation information, a novel event-triggered strategy is proposed to conserve communication resources. A linear matrix inequality based condition is derived based on a piecewise Lyapunov function. This condition guarantees the stability of the closed-loop system

Ubiquitous power Internet of Things (IoT) is a smart service system oriented to all aspects of the power system, and has the characteristics of universal interconnection, human-computer interaction, comprehensive state perception, efficient information processing, and other convenient and flexible applications. It has become a hot topic in the field of IoT. We summarize some existing research work

We propose a new asymmetric pixel confusion algorithm for images based on the Rivest-Shamir-Adleman (RSA) public-key cryptosystem and Arnold map. First, the RSA asymmetric algorithm is used to generate two groups of Arnold transform parameters to address the problem of symmetrical distribution of Arnold map parameters. Second, the image is divided into blocks, and the first group of parameters is used

In underwater scenes, the quality of the video and image acquired by the underwater imaging system suffers from severe degradation, influencing target detection and recognition. Thus, restoring real scenes from blurred videos and images is of great significance. Owing to the light absorption and scattering by suspended particles, the images acquired often have poor visibility, including color shift

Success has been obtained using a semi-supervised graph analysis method based on a graph convolutional network (GCN). However, GCN ignores some local information at each node in the graph, so that data preprocessing is incomplete and the model generated is not accurate enough. Thus, in the case of numerous unsupervised models based on graph embedding technology, local node information is important

As a cutting-edge branch of unmanned aerial vehicle (UAV) technology, the cooperation of a group of UAVs has attracted increasing attention from both civil and military sectors, due to its remarkable merits in functionality and flexibility for accomplishing complex extensive tasks, e.g., search and rescue, fire-fighting, reconnaissance, and surveillance. Cooperative path planning (CPP) is a key problem

In traditional target tracking methods, the angle error and range error are often measured by the empirical value, while observation noise is a constant. In this paper, the angle error and range error are analyzed. They are influenced by the signal-to-noise ratio (SNR). Therefore, a model related to SNR has been established, in which the SNR information is applied for target tracking. Combined with

We study a mobile edge computing system assisted by multiple unmanned aerial vehicles (UAVs), where the UAVs act as edge servers to provide computing services for Internet of Things devices. Our goal is to minimize the energy consumption of this system by planning the trajectories of UAVs. This problem is difficult to address because when planning the trajectories, we need to consider not only the

Although deep neural networks (DNNs) have achieved great success in semantic segmentation tasks, it is still challenging for real-time applications. A large number of feature channels, parameters, and floating-point operations make the network sluggish and computationally heavy, which is not desirable for real-time tasks such as robotics and autonomous driving. Most approaches, however, usually sacrifice

Special curves in the Minkowski space such as Minkowski Pythagorean hodograph curves play an important role in computer-aided geometric design, and their usages are thoroughly studied in recent years. Bizzarri et al. (2016) introduced the class of Rational Envelope (RE) curves, and an interpolation method for G1 Hermite data was presented, where the resulting RE curve yielded a rational boundary for

Much recent progress in monaural speech separation (MSS) has been achieved through a series of deep learning architectures based on autoencoders, which use an encoder to condense the input signal into compressed features and then feed these features into a decoder to construct a specific audio source of interest. However, these approaches can neither learn generative factors of the original input for

Cyber-physical systems (CPSs) are becoming increasingly important in safety-critical systems. Particular risk analysis (PRA) is an essential step in the safety assessment process to guarantee the quality of a system in the early phase of system development. Human factors like the physical environment are the most important part of particular risk assessment. Therefore, it is necessary to analyze the

Cyber-physical systems (CPSs) have emerged as a potential enabling technology to handle the challenges in social and economic sustainable development. Since it was proposed in 2006, intensive research has been conducted, showing that the construction of a CPS is a hard and complex engineering process due to the nature of integrating a large number of heterogeneous subsystems. Among other approaches

Robotic swarms are usually designed in a bottom-up way, which can make robotic swarms vulnerable to environmental impact. It is particularly true for the widely used control mode of robotic swarms, where it is often the case that neither the correctness of the swarming tasks at the macro level nor the safety of the interaction among agents at the micro level can be guaranteed. To ensure that the behaviors