IEEE Transactions on Vehicular Technology

Dithering quantization (DQ) is a promising Differential Privacy (DP) approach designed for Federated Learning (FL) to prevent privacy leakage of clients. However, DQ-FL inevitably exacerbates the decline in model accuracy in FL, particularly under conditions characterized by straggler effects and statistical heterogeneity across clients. In this paper, we propose a novel Adaptive Dithering Quanti…

This paper investigates scalable user scheduling in low-altitude, wideband cell-free radio access networks (CF-RANs), where scheduling is decentralized to user-centric distributed units (UCDUs), enabling scalable medium access control (MAC)-layer operation. Firstly, to provide analytical insights into the impact of distributed nature of CF-RAN, a closed-form expression for the uplink spectral eff…

High-precision positioning in GPS-denied environments is a challenging yet critical technology. Resonant beam positioning (RBP) utilizes a resonant beam with properties such as energy focusing, self-establishment, self-alignment, and passive operation, offering a promising solution for this task. However, traditional RBP algorithms require a fixed number of resonant beam base stations, which can …

This paper addresses the challenge of balancing per-station throughput and overall fairness for IEEE 802.11ah uplink scenarios with heterogeneous link conditions and shared-medium contention. We propose a learning-based MAC-layer enhancement that replaces the backoff mechanism with a policy-driven transmission decision, enabling explicit Pareto-guided control of the throughput-fairness trade-off.…

Constructing a no-fly zone (NFZ) is a straightfor ward and effective way to facilitate the coexistence of unmanned aerial vehicles (drones) and existing systems (typically satellite systems). However, there has been little work on designing such an NFZ that minimizes its volume while satisfying interference constraints set by regulatory bodies. In the absence of this design, one invariably ends u…

Reconfigurable intelligent surface (RIS)-aided rate splitting multiple access (RSMA) systems have demonstrated remarkable potential in enhancing spectral efficiency. However, most existing works rely on ideal hardware, which is unrealistic. In practical deployments, RIS elements suffer from amplitude–phase coupling, where transceivers are subject to hardware impairments (HWI), and successive inte…

In this paper, we consider an uplink grant-free access scheme for machine-type communications (MTC) in a railway scenario, inspired by the semi-persistent scheduling approach and motivated by railway operation environment monitoring. The scheme assumes a co-existence scenario, grouping critical MTC (cMTC) and massive MTC (mMTC) users and assigning them recurring uplink slots in a non-orthogonal m…

This paper investigates the distributed practical prescribed-time formation control problem for uncertain un manned ground vehicle (UGV) systems via an improved state constraints approach. First, an adaptive formation controller with a prescribed-time gain is developed to guarantee UGVs achieve exact desired formations within user-defined time in tervals. Unlike conventional methods requiring inf…

We develop a pragmatic multi-user (MU) massive multiple-input multiple-output (MIMO) channel model tailored to the THz band, encompassing factors such as molecular absorption, reflection losses and multipath diffused ray components. Next, we propose a novel semi-blind based channel state information (CSI) acquisition technique i.e. MU whitening decorrelation semi-blind (MU-WD-SB) that exploits th…

The rapid emergence of smart cities, the growing popularity of Electric Vehicle (EV) systems, and the deployment of Vehicular Ad Hoc Networks (VANETs) and integrated charging structures have boosted the implementation of VANETs and cross-platform service requests. Due to their open and dynamic nature, the networks are easy targets for a variety of security threats, including identity tracing, mes…

The intelligent waveform design is becoming essential for the integrated sensing and communication (ISAC) in future 6G networks, where the orthogonal frequency-division multiplexing (OFDM) signals with desirable correlation proper ties play a critical role in ensuring the reliable sensing and communication performance. However, the traditional optimization methods, such as majorization-minimizati…

Recently, fluid antenna (FA) systems integrated with reconfigurable intelligent surfaces (RIS) have attracted widespread attention as a highly promising technology for enhancing communication performance. Against this backdrop, to address the key limitations of existing FA index modulation, we propose a RIS enhanced code index modulation (CIM) scheme for grouped FA systems (GFA-RIS-CIM). Specific…

This paper proposes a tensor-based modulation classification scheme for Multiple Input Multiple Output systems operating under malicious interference. The method begins by constructing a high-dimensional mutual cumulative tensor and applying a natural gradient Candecomp/Parafac (CP) decomposition algorithm for blind interference separation. To reduce complexity, a compact three-dimensional tensor…

This paper presents a comprehensive measurement-based trajectory-aware characterization of low-altitude Air-to-Ground (A2G) channels in a suburban environment. A 64-element Massive Multi-Input Multi-Output (MaMIMO) array was used to capture channels for three trajectories of an Uncrewed Aerial Vehicle (UAV), including two horizontal zig-zag flights at fixed altitudes and one vertical ascent, chos…

Integrated satellite–terrestrial networks (ISTNs) of fer a compelling architecture for extending coverage beyond the limits of terrestrial infrastructure, Yet, despite their growing practical relevance, a unified and tractable mathematical frame work for analyzing their performance remains underdeveloped. In this paper, we develop a stochastic-geometry-based frame work for analyzing the downlink …

Cell-free massive multiple-input multiple-output (MIMO) systems and reconfigurable intelligent surfaces (RIS) have attracted significant attention as promising technologies for 6G communication networks. Achieving comprehensive vehicle to-ground communication coverage and mitigating frequent han dover events induced by high-speed mobility remain significant challenges in high-speed train (HST) sc…

This paper investigates energy-efficient integrated sensing and communication (ISAC) aided by multiple active reconfigurable intelligent surfaces (active-RISs). We develop a multi-active-RIS-enabled joint beamforming framework and formulate a system-level power optimization problem that explicitly accounts for the active-RIS amplification power in ISAC. To support real-time beamforming decisions,…

Radio Frequency Fingerprinting (RFF) is a promising technique for physical-layer hardware identification. Among various hardware-induced features, nonlinear distortions introduced by power amplifiers (PAs) contribute significantly to the overall RFF. However, fingerprint components related to PA behavior are sensitive to PA module replacement, variations in transmit power, and their coupling with…

This paper proposes two quadrature amplitude modulation (QAM) constellation integration schemes for recon figurable intelligent surface (RIS)-enabled symbiotic backscatter systems termed Schemes I and II, where the primary and backscatter signals merge into a standard 16-QAM constellation by offsetting the amplitude-phase coupling effects of a practically measured RIS, Specifically, the primary a…

The use of communication signal echoes for monostatic radar sensing is an emerging research area in the field of joint radar and communication (JRC). Block orthogonal frequency division multiplexing (OFDM) modulation with cyclic prefix (CP) is widely adopted by many wireless communication standards in the mm-wave band, such as IEEE 802.11ad and cellular vehicle-to-vehicle sidelink in the Frequenc…