High-speed railway (HSR) brings convenience to peoples' lives and is generally considered as one of the most sustainable developments for ground transportation. One important parts HSR construction signaling system, which also called "operation control system," where wireless communications play a key role in transmission train data. We discuss detail main differences scientific research between operation scenarios conventional public land mobile scenarios. The latest progress channel...

The application scenarios and requirements are more diverse in the fifth-generation (5G) era than before. In order to successfully support system design deployment, accurate channel modeling is important. Ray-tracing (RT) based deterministic approach with detailed angular information a suitable candidate for predicting time-varying multiple-input multiple-output (MIMO) various frequency bands. However, computational complexity utility of RT main concerns users. Aiming at 5G beyond wireless...

High-speed railways (HSRs) improve the quality of rail services, yield greater customer satisfaction, and help to create socioeconomically balanced societies [1]. This highly efficient transport mode creates significant challenges in terms investment, technology, industry, environment. To handle increasing traffic, ensure passenger safety, provide real-time multimedia information, a new communication system for HSR is required. In last decade, public networks have been evolving from...

Unmanned aerial vehicle (UAV) wireless communications has experienced an upsurge of interest in both military and civilian applications, due to its high mobility, low cost, on-demand deployment, inherent line-of-sight air-to-ground channels. However, these benefits also make UAV communication systems vulnerable malicious eavesdropping attacks. In this article, we aim examine the physical layer security issues systems. particular, passive active are two primary types attack We provide...

Railway communications has attracted significant attention from both academia and industries due to the booming development of railways, especially high-speed railways (HSRs). To be in line with vision future smart rail communications, transport industry needs develop innovative communication network architectures key technologies that ensure high-quality transmissions for passengers railway operations control systems. Under high mobility safety, eco-friendliness, comfort, transparency,...

This paper investigates the application of simultaneous wireless information and power transfer (SWIPT) to cooperative non-orthogonal multiple access (NOMA). A new multiple-input single-output (MISO) SWIPT NOMA protocol is proposed, where a user with strong channel condition acts as an energy-harvesting (EH) relay by adopting splitting (PS) scheme help poor condition. By jointly optimizing PS ratio beamforming vectors, we aim at maximizing data rate "strong user" while satisfying QoS...

As a widely acknowledged efficient and green transportation model, rail traffic is expected to evolve into new era of “smart mobility” whereby infrastructure, trains, travelers will be interconnected achieve optimized mobility, higher safety, lower costs. Thus, seamless high-data rate wireless connectivity with up dozens gigahertz bandwidth required. Such huge requirement motivates the exploration underutilized millimeter (mm) wave terahertz (THz) bands. In this paper, motivations for...

This work introduces downlink non-orthogonal multiple access (NOMA) into short-packet communications. NOMA has great potential to improve fairness and spectral efficiency with respect orthogonal (OMA) for low-latency transmission, thus making it attractive the emerging Internet of Things. We consider a two-user system finite blocklength constraints, in which transmission rates power allocation are optimized. To this end, we investigate trade-off among rate, decoding error probability,...

Wireless vehicular communications and sensing technologies are key to enabling more advanced intelligent transportation systems (ITSs) with improved safety efficiency. Within the realm of wireless communication, millimeter-wave (mmwave) technology has recently received much attention, providing rich spectrum resources support timely transmission large amounts data. This is especially important for applications because number sensors on modern vehicles rapidly increasing thus generating To...

The millimeter wave (mmWave) communications and massive multiple-input multiple-output (MIMO) are both widely considered to be the candidate technologies for fifth generation mobile communication system. It is thus a good idea combine these two achieve better performance large capacity high data-rate transmission. However, one of fundamental challenges characterization mmWave MIMO channel. Most previous investigations in channel only focus on single-input single-output links or links,...

A geometric multiple-input multiple-output (MIMO) channel model is proposed for millimeter-wave (mmWave) mobile-to-mobile (M2M) applications based on the two-ring reference model, where cluster-based nonisotropic scattering at both ends of radio link considered. The employs a few clusters scatterers located two rings centered transmitter and receiver, intracluster azimuth spread further characterized according to mmWave characteristics. From time-frequency correlation function, power delay...

Vehicle-to-vehicle (V2V) communication is an enabler for improved traffic safety and congestion control. As any wireless system, the ultimate performance limit determined by propagation channel. A particular point of interest shadowing effect large vehicles such as trucks buses, this might affect range significantly. In paper we present measurement results model channel, in which a bus acts either object or relay between two passenger cars. The setup based on Wireless Open-Access Research...

In this paper, we investigate the specific emitter identification (SEI) problem, which distinguishes different emitters using features generated by nonlinearity of power amplifiers emitters. SEI is performed measuring representing individual specifications and making a decision based on their differences. problem considered in both single-hop relaying scenarios, three algorithms Hilbert spectrum are proposed. The first employs entropy first- second-order moments as features, describe...

Discriminating between line-of-sight (LOS) and non-line-of-sight (NLOS) conditions, or <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LOS identification</i> , is important for a variety of purposes in wireless systems, including localization channel modeling. LOS identification especially challenging vehicle-to-vehicle (V2V) networks since physical effects that occur at different spatial/temporal scales can affect the presence LOS. This...

This two-part paper investigates the application of artificial intelligence (AI) and, in particular, machine learning (ML) to study wireless propagation channels. In Part I this article, we introduced AI and ML provided a comprehensive survey on ML-enabled channel characterization antenna-channel optimization, part (Part II), review state-of-the-art literature scenario identification modeling here. key ideas for modeling/prediction are presented, widely used methods prediction analyzed...

This paper reports (i) a set of measurements the wireless propagation channel at 930 MHz, conducted along "Zhengzhou-Xian" high-speed railway China in various viaduct scenarios, and (ii) an analysis modeling small-scale large-scale parameters based on those measurements. The environment can be categorized into four cases, covering viaducts with different heights suburban environments. Small values fade depth, level crossing rates, average duration are observed. Akaike's Information Criterion...

More people prefer to using rail traffic for travel or commuting due its convenience and flexibility. As the record of maximum speed has been continuously broken new applications are foreseen, high-speed railway (HSR) communication system requires higher data rate with seamless connectivity, therefore, design faces challenges support high mobility. Millimeter-wave (mmWave) technologies considered as candidates provide wideband communication. However, mmWave is rarely explored in HSR...

Cluster-based channel modeling has been an important trend in the development of model, as it maintains accuracy while reducing complexity. Whereas a large number measurements have shown that multipath components (MPCs) are distributed groups, i.e., clusters, existing clustering algorithms various drawbacks with respect to complexity, threshold choices, and/or assumptions about prior knowledge. In this paper, kernel-power-density (KPD)-based algorithm is proposed for MPC clustering. It uses...

Based on the narrowband 930-MHz measurements taken along "Zhengzhou-Xi'an" high-speed railway in China, an empirical path loss model is proposed. It applicable to viaduct scenarios, considering influences of height <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</i> and base station antenna relative xmlns:xlink="http://www.w3.org/1999/xlink">h</i> , which are not well-covered by existing large-scale models. The exponents investigated, based...

The upcoming fifth-generation (5G) mobile communication system is expected to support high mobility up 500 km/h, which envisioned in particular for high-speed trains. Millimeter wave (mmWave) spectrum considered as a key enabler offering the "best experience" highly users. Despite that channel characterization necessary mmWave design and validation, it still not feasible directly do extensive measurements on moving trains (HST) at speed km/h present. Thus, rather than conducting HST sounding...

Accurate characterization of the radio channel in tunnels is great importance for new signaling and train control communications systems. To model this environment, measurements have been taken at 2.4 GHz a real environment Madrid subway. The were carried out with four base station transmitters installed 2-km tunnel using mobile receiver on standard train. First, an optimum antenna configuration, all propagation characteristics complex subway including near shadowing, path loss, shadow...

Cuttings are widely used in high-speed railway (HSR) transportation to ensure the flatness of rails. The special structure cuttings results rich reflection and scattering, creates dense multipath components. This paper presents a series measurements propagation channel at 930 MHz conducted along "Zhengzhou-Xi'an" HSR China, characterize small-scale fading behavior rail-cutting scenarios as function geometry cuttings, including crown width bottom width. Raw data collected six (five for...

Terahertz (THz) Kiosk application offers ultrahigh downloads of digital information to users' handheld devices. System configuration and multiple paths between the transmitter receiver have important impact on achievable data rates. In this paper, propagation channel THz downloading is investigated a stochastic model proposed. Based measurements using vector network analyzer, 3-D ray-tracing simulator calibrated conduct simulations for an in-depth analysis different characteristics....

This paper proposes a novel direction-of-arrival (DOA)-aided channel estimation for hybrid millimeter-wave (mm-wave) massive multiple-input multiple-output system with uniform planar array at the base station. To explore physical characteristics of antenna in mm-wave systems, parameters each path are decomposed into DOA information and gain information. We first estimate initial DOAs uplink through 2-D discrete Fourier transform enhance accuracy via angle rotation technique. then using small...

In this paper, a novel joint design of beamforming and power allocation is proposed for multi-cell multiuser multiple-input multiple-output (MIMO) non-orthogonal multiple access (NOMA) network. network, base stations (BSs) adopt coordinated multipoint (CoMP) downlink transmission. We study new scenario where the users are divided into two groups according to their quality-of-service (QoS) requirements, rather than channel qualities as investigated in literature. Our aims maximize sum-rate...