Unmanned aerial vehicles (UAVs) have been widely used in both military and civilian applications. Equipped with diverse communication payloads, UAVs cooperating satellites base stations constitute a space-air-ground three-tier heterogeneous network, which are beneficial terms of providing the seamless coverage as well improving capacity for increasingly prosperous Internet Things networks. However, cross-tier interference may be inevitable among these tightly embraced networks when sharing...

Integrated sensing and communication (ISAC) has recently emerged as a candidate 6G technology, aiming to unify the two key operations of future network in spectrum/energy/cost-efficient way. ISAC systems communicate sense for targets using common waveform, hardware platform, ultimately same infrastructure. Nevertheless, inclusion information signaling probing waveform target raises challenges from perspective security. At time, capability incorporated transmission offers unique opportunities...

We study security solutions for dual-functional radar communication (DFRC) systems, which detect the target and communicate with downlink cellular users in millimeter-wave (mmWave) wireless networks simultaneously. Uniquely such scenarios, is regarded as a potential eavesdropper might surveil information sent from base station (BS) to (CUs), that carried by probing signal. Transmit waveform receive beamforming are jointly designed maximize signal-to-interference-plus-noise ratio (SINR) of...

Industrial metaverse, as an emerging paradigm of the next generation industry transformation, aims to build a fully immersive virtual space that can interact with physical in real time, and enhance its operation process efficiency. Short-packet communication takes substantial portion data exchange, which requires extremely high reliability low latency, keep information fresh, measure Age Information (AoI), Given stringent requirements, coupled systems limited resources, achieving interactive...

In this paper, a novel reconfigurable intelligent surface (RIS)-assisted HAP-UAV secure multi-user mixed radio frequency (RF)/free space optical (FSO) system is proposed. Specifically, the Gamma-Gamma distribution utilized to characterize atmospheric turbulence effect for FSO link from UAV HAP, while Rayleigh and Nakagami- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$m$ </tex-math></inline-formula>...

We provide a comprehensive energy efficiency (EE) analysis of the full-duplex (FD) and half-duplex (HD) amplify-and-forward (AF) relay-assisted 60-GHz dual-hop indoor wireless systems, aiming to answer question which relaying mode is greener (more efficient) address issue EE optimization. develop an opportunistic selection scheme, where FD with one-stage self-interference cancellation (passive suppression) or two-stage suppression + analog cancellation) HD opportunistically selected,...

IoT is emerging as the future evolution of Internet, aiming to provide connectivity for everyone and everything. Since expected carry important private information, a high level PHY security critical wireless communications in IoT, complement traditional techniques that are employed at layers. In this overview, we examine recent interest energy-efficient cost-efficient solutions securing downlink transmission through interference exploitation. This exciting line research departs from...

Full-duplex (FD) relaying is a promising solution for fifth generation (5G) wireless communications due to its potential provide high spectral efficiency (SE) transmission. However, FD relay nodes consume much higher power than half-duplex nodes, especially in millimeter (mm)-wave band. Therefore, energy-efficiency (EE) an important issue address mm-wave systems, which highlights the green evolution of 5G communications. Existing related research SE-oriented, not efficient cutting carbon...

Traditional physical layer secure beamforming is achieved via precoding before signal transmission using channel state information (CSI). However, imperfect CSI will compromise the performance with and potential leakage. In addition, multiple RF chains antennas are needed to support narrow beam generation, which complicates hardware implementation not suitable for resource-constrained Internet-of-Things (IoT) devices. Moreover, advancement of artificial intelligence (AI), low-cost...

The full-duplex (FD) cooperative nonorthogonal multiple access (NOMA) achieves a superior throughput over the conventional half-duplex (HD) NOMA, wherein strong users (SUs) with good channel conditions can act as an FD relay node for weak poor conditions. However, energy efficiency (EE) of NOMA may be degraded due to additional power consumption incurred at SUs. We are, therefore, motivated investigate EE maximization problem system. More importantly, we "signal-to-inference-noise ratio gap...

Recently, fog-computing-based radio access networks (F-RANs) have been conceptualized to provide high quality of experience (QoE) for adaptive bit rate (ABR) streaming, where additional computing capacity is supplemented on fog nodes facilitate complicated cross-layer optimization (i.e., joint selection and resource allocation). However, finding an optimal global solution with acceptable complexity still infeasible by the conventional methods. In this work, we propose artificial intelligence...

In the era of big data, anonymity is recognized as an important attribute in privacy-preserving communications. The existing anonymous authentication and routing designs are applied at higher layers networks, ignoring fact that physical layer (PHY) also contains privacy-critical information. this paper, we introduce concept PHY anonymity, reveal receiver can unmask sender's identity by only analyzing information, i.e., signaling patterns characteristics channel. We investigate two scenarios,...

Energy-efficiency (EE)-oriented green communication design is an important issue at 60 GHz due to high power consumption of devices working such a frequency. In this paper, we investigate EE-oriented resource allocation for full-duplex (FD) decode-and-forward relay-assisted 60-GHz multiuser indoor systems. contrast the existing spectral efficiency (SE)-oriented designs, our scheme maximizes EE FD relaying system under cross-layer constraints, addressing typical problems GHz, as intermittent...

In this paper, we propose a series of novel coordination schemes for multi-cell downlink communication. Starting from full base station (BS) coordination, first fully-coordinated scheme to exploit beneficial effects both inter-cell and intra-cell interference, based on sharing channel state information (CSI) data among the BSs. To reduce overhead, then partially-coordinated where only interference is designed be constructive while jointly suppressed by coordinated Accordingly, involves CSI...

In wireless power transfer (WPT)-assisted relaying systems, spectral efficiency (SE) of source-relay link plays a dominant role in system SE performance due to the limited transmission at WPT-aided relay. this paper, we propose novel protocol for downlink orthogonal frequency division multiple access (OFDMA) with relay operating full-duplex (FD) decode-and-forward (DF) mode, where time slot durations and relay-users hops are designed be dynamic, enhance utilization degrees freedom hence SE....

Both information age and delay are critical performance metrics of emerging time-sensitive applications. However, their inherent correlation in the finite block length (FBL) regime has remained uninvestigated as it is affected by update rate a complex manner. In this paper, closed-form expressions for average (AoI), peak AoI (PAoI) derived an FBL Last-Come First-Served system with retransmission non-preemption policies, based on which comprehensive analysis relationship among three...

In this paper, we investigate unmanned aerial vehicle (UAV) assisted communication systems that require quasi-balanced data rates in uplink (UL) and downlink (DL), as well users’ heterogeneous traffic. To the best of our knowledge, is first work to explicitly joint UL-DL optimization for UAV under requirements. A hybrid-mode multiple access (HMMA) scheme proposed toward traffic, where non-orthogonal (NOMA) targets high average rate, while orthogonal (OMA) aims meet instantaneous rate demands...

We consider a multi-cell non-orthogonal multiple access (NOMA) system with coordinated base stations and investigate its downlink user coordination mode selection resource allocation to green the while maintaining high spectral efficiency, in presence of inter-cell interference. To best our knowledge, this is first work criteria for NOMA systems, fuzzy logic (FL) based approach proposed balance among achieve higher robustness against combined effect shadowing, fading interference, compared...

We investigate a multi-device ultra-reliable low-latency communication system with heterogeneous traffic and finite block length over temporally-correlated fading channels. In light of the challenging demand for accurate channel estimation limited pilot in short frame, two frame structures, which respectively adopt independent pilots shared pilot, are investigated. Block lengths jointly optimized through instantaneous state information (CSI) based dynamic optimization statistical CSI static...

We propose a bidirectional distributed antenna (DA) system where DAs are capable of working dynamically in hybrid duplex modes: full (FD), half duplex, and sleep, which enables higher degree freedom hence much energy efficiency (EE) than DA sole-FD systems, with just marginal loss spectral (SE). The proposed also demonstrates significant EE SE enhancement over FD colocated systems. Compared to the above two benchmark requires simpler self-interference cancelation design for mode due less...

In this paper, directional modulation (DM) is investigated to enhance physical layer security. Practical transmitter designs are exploited under imperfect channel state information (CSI) and hardware constraints, such as finite-resolution phase shifters (PSs) per-antenna power budget. Tailored for the practical issues in realizing DM, a series of scenarios investigated. Starting from scenario where eavesdroppers (Eve)s' completely unknown, corresponding proposed optimize legitimate users...

We present a comprehensive review for wireless power transfer (WPT)-aided full-duplex (FD) relay systems. Two critical challenges in implementing WPT-aided FD systems are presented, that is, pseudo realization and high consumption. Existing time-splitting or power-splitting structure based-WPT-aided can only realize operation one of the time slots forward part received signal to destination, belonging realization. Besides, self-interference is treated as noise cancellation (SIC) incurs...