The recent concept of beamspace multiple input output (MIMO) can significantly reduce the number required radio frequency (RF) chains in millimeter-wave (mmWave) massive MIMO systems without obvious performance loss. However, fundamental limit existing is that supported users cannot be larger than RF at same time-frequency resources. To break this limit, paper, we propose a new spectrum and energy-efficient mmWave transmission scheme integrates non-orthogonal access (NOMA) with MIMO, i.e.,...

With the rapid development of marine activities, there has been an increasing number Internet-of-Things (IoT) devices on ocean. This leads to a growing demand for high-speed and ultrareliable maritime communications. It reported that large performance loss is often inevitable if existing fourth-generation (4G), fifth-generation (5G), or satellite communication technologies are used directly Hence, conventional theories methods need be tailored this scenario match its unique characteristics,...

The unmanned aerial vehicle (UAV) is a promising enabler of the Internet Things (IoT) vision, due to its agile maneuverability. In this paper, we explore potential gain UAV-aided data collection in generalized IoT scenario. Particularly, composite channel model, including both large-scale and small-scale fading used depict typical propagation environments. Moreover, rigorous energy constraints are considered characterize devices as practically possible. A multiantenna UAV employed, which can...

In this paper, we investigate the downlink transmission of a non-orthogonal multiple access (NOMA)-based integrated terrestrial-satellite network, in which NOMA-based terrestrial networks and satellite cooperatively provide coverage for ground users while reusing entire bandwidth. For both multi-antennas are equipped beamforming techniques utilized to serve simultaneously. A channel quality-based scheme is proposed select satellite, then formulate user pairing as max-min problem maximize...

Due to the agile maneuverability, unmanned aerial vehicles (UAVs) have shown great promise for on-demand communications. In practice, UAV-aided base stations are not separate. Instead, they rely on existing satellites/terrestrial systems spectrum sharing and efficient backhaul. this case, how coordinate satellites, UAVs terrestrial is still an open issue. paper, we deploy coverage enhancement of a hybrid satellite-terrestrial maritime communication network. Using typical composite channel...

The virtual multiple input output (MIMO) technique can dramatically improve the performance of a multi-cell distributed antenna system (DAS), thanks to its great potentials for inter-cell interference mitigation. One most challenging issues MIMO is acquisition channel state information at transmitter (CSIT), which usually leads an overwhelming amount overhead. In this work, we focus on case that only slowly-varying large-scale required transmitter, and explore gain be achieved by coordinated...

Current fifth generation (5G) cellular networks mainly focus on the terrestrial scenario. Due to difficulty of deploying communications infrastructure ocean, performance existing maritime communication (MCNs) is far behind 5G. This problem can be solved by using unmanned aerial vehicles (UAVs) as agile platforms enable on-demand coverage, a supplement marine satellites and shore-based based stations (TBSs). In this article, we study integration UAVs with MCNs, investigate potential gains...

The millimeter-wave (mmWave) communication is envisioned to provide orders of magnitude capacity improvement. However, it challenging realize a sufficient link margin due high path loss and blockages. To address this difficulty, in paper, we explore the potential gain ultra-densification for enhancing mmWave communications from network-level perspective. By deploying base stations (BSs) an extremely dense amorphous fashion, access distance reduced choice serving BSs enriched each user, which...

Reconfigurable intelligent surfaces (RISs), consisting of many low-cost elements that reflect the incident waves by an adjustable phase shift, have attracted sudden attention for their potential reconfiguring signal propagation environment and enhancing performance wireless networks. The passive nature RISs is indeed beneficial, but lack radio frequency (RF) chains at RIS has made channel estimation extremely challenging. We face this challenge proposing a joint transmit precoding framework...

In this paper, we investigate the downlink cooperative multigroup multicast transmission in integrated terrestrial-satellite network, which base stations (BSs) and satellite provide service for ground users a manner while reusing entire bandwidth. For both terrestrial BSs satellite, multiantennas are equipped beamforming techniques utilized improving system performance. Based on architecture, formulate weighted max-min fair (MMF) design problem to jointly optimize vectors of is solved based...

The ever-increasing demands for local area services underlaying cellular networks benefit from direct device-to-device (D2D) communications, where an efficient scheme resource allocation is needed to increase the system capacity as result of interference caused by spectrum sharing. Current works mainly focus on maximizing overall transmission according constraints physical domain. However, D2D users in social domain form different communities, and each community likely improve its own...

Satellite networks are able to provide seamless services for ground users with wide coverage, which is intrinsically suitable providing broadcasting or multicasting services. While terrestrial have experienced rapid development in recent years, next generation communications, the architecture of integrated terrestrial-satellite promising enable seamlessly access all types In this article, we investigate problem cooperative transmission networks, where two cases unicast and multicast...

Current fifth-generation (5G) networks do not cover maritime areas, causing difficulties in developing Internet of Things (IoT). To tackle this problem, we establish a nearshore network by collaboratively using on-shore terrestrial base stations (TBSs) and tethered unmanned aerial vehicles (UAVs). These TBSs UAVs form virtual clusters user-centric manner. Within each cluster, non-orthogonal multiple access (NOMA) is adopted for agilely including various IoT devices, which are usually...

Wideband extremely large-scale multiple-input-multiple-output (XL-MIMO) plays an important role in boosting the data rate for 6G networks. Because of huge bandwidth and large number antennas, wideband XL-MIMO introduces a significant near-field beam split effect, where beams at different frequencies are focused on locations. This effect results severe array gain loss, existing works mainly consider to compensate this loss by utilizing time-delay (TD) beamforming. paper demonstrates that...

The sixth-generation (6G) network is envisioned to integrate communication and sensing functions, so as improve the spectrum efficiency support explosive novel applications. Although similarities of wireless radio lay foundation for their combination, there still considerable incompatible interest between them. To simultaneously guarantee capacity accuracy, multiple-input multiple-output (MIMO) technique plays an important role due its unique capability spatial beamforming waveform shaping....

Mobile edge computing (MEC) is considered a novel paradigm for computation-intensive and delay-sensitive tasks in fifth generation (5G) networks beyond. However, its uncertainty, referred to as dynamic randomness, from the mobile device, wireless channel, network sides, results high-dimensional, nonconvex, nonlinear, NP-hard optimization problems. Thanks evolved reinforcement learning (RL), upon iteratively interacting with random environment, trained agent can intelligently obtain optimal...

The upcoming sixth generation (6G) network is expected to be more open and heterogeneous, posing new challenges conventional security architectures. Traditionally, these architectures rely on the construction of a perimeter at boundaries. In this article, we propose software-defined zero trust architecture (ZTA) for 6G networks, offering promising approach establish an elastic scalable regime. Our proposed ensures secure access control through adaptive collaborations among domains,...

To accurately predict the matching relationships between various components and engine performance in whole aero-engine environment, this study introduces a two-dimensional throughflow simulation method for aero-engine. This is based on individual solvers turbo-machinery combustor. It establishes model by integrating with compressor-turbine co-operating equations boundary conditions. The solver employs circumferentially averaged form of time-dependent Navier-Stokes (N-S) as governing...

In this paper, we investigate low complexity antenna selection schemes in spatial modulation (SM). Firstly, propose a reduced scheme based on pairwise error probability (PEP). It demonstrates that there is almost no performance loss the proposed compared to original algorithm, while can be significantly especially with high order. Secondly, an correlation. novel criterion which fundamentally different from those traditional multiple-input multiple output (MIMO) systems. also reduces...

This paper investigates the dynamic effects of reentry plasma sheath on electromagnetic wave propagation from viewpoint communication. Both spatial turbulence and temporal variation electron density are included in our model, transmission matrix method is employed to investigate interactions between wave. The simulation results indicated that because nonlinear property plasma, amplitude caused by has a lognormal distribution, while phase fluctuation Rayleigh distributed. Moreover, with...

Energy efficiency is a crucial issue for maritime communications, due to the high path loss and limited number of geographically available base station sites. Different from previous studies, we promote energy by exploiting specific characteristics channels user mobility. Particularly, utilize shipping lane information marine users estimate their large-scale channel state information. Based on that, resource allocation jointly optimized all over time slots during voyage, which mixed 0-1...

The integrated terrestrial-satellite network (ITSN) combines cellular networks and satellite to provide services for the ever-increasing users, where coexistence of two systems can not only highlight their advantages but also bring serious interference. Confronted with target maximizing capacity ensuring quality-of-service (QoS) large number we propose a framework-involved joint optimization multigroup precoding resource allocation in ITSN. In precoding, ameliorate interference by optimizing...

Time-sensitive services (TSSs) have been widely envisioned for future sixth-generation (6G) wireless communication networks. Due to its inherent low-latency advantage, mobile-edge computing (MEC) will be an indispensable enabler TSSs. The random characteristics of the delay experienced by users are key metrics reflecting Quality Service (QoS) Most existing studies on MEC focused average delay. Only a few research efforts devoted other characteristics, such as delay-bound violation...

In fifth generation (5G) and beyond Internet of Things (IoT), it becomes increasingly important to serve a massive number IoT devices outside the coverage terrestrial cellular networks. Due their own limitations, unmanned aerial vehicles (UAVs) satellites need coordinate with each other in holes 5G, leading cognitive satellite-UAV network (CSUN). this paper, we investigate multi-domain resource allocation for CSUNs consisting satellite swarm UAVs, so as improve efficiency access wide areas....

In the upcoming sixth-generation (6G) era, demand for constructing a wide-area time-sensitive Internet of Things (IoT) continues to increase. As conventional cellular technologies are difficult directly use IoT, it is beneficial non-terrestrial infrastructures, including satellites and unmanned aerial vehicles (UAVs). Thus, we can build network (NTN) using cell-free architecture. Driven by requirements uneven distribution IoT devices, NTN must be empowered mobile edge computing (MEC) while...