Prediction-Window Aided Fluid Antenna Systems for High-Mobility Communications
Huang Yinning, Zeng Cheng, Yang Zhaohui
[Introduction] Fluid antenna systems (FAS) have emerged as a revolutionary technology for next-generation wireless networks, offering continuous spatial degrees of freedom. However, deploying FAS on high-speed mobile embodied intelligent agents induces severe Doppler shifts, leading to an overhead catastrophe when traditional full-port scanning is applied within the sharply reduced channel coherence time. To overcome this bottleneck, this paper proposes a prediction-aided adaptive communication architecture with a local window. Rather than relying on rigid global scanning or highly vulnerable single-point prediction, our mechanism constructs a dynamic local sounding window centered on upper-layer prediction results. By exploiting the inherent spatial channel correlation of FAS, this approach effectively bridges prediction deviations and achieves an optimal balance between pilot overhead and spatial diversity gain. Specifically, we establish a rigorous cross-layer quantitative analysis model for long-term expected throughput. This model integrates a nonlinear bounded hit probability function and a novel gain bridging model based on the zero-order Bessel function of the first kind. Based on this framework, we formulate a discrete optimization problem subject to strict timing constraints to maximize the expected transmission capacity. To solve this non-convex problem efficiently, we design a two-stage low-complexity algorithm that combines offline spatial expectation decoupling with online discrete zeroth-order gradient optimization. This algorithm completely decouples real-time computational complexity from the total number of antenna ports, enabling microsecond-level adaptive tracking of the optimal window. Extensive simulation results demonstrate that the proposed mechanism can adaptively adjust the sounding window scale in response to real-time moving velocity and prediction accuracy. Consequently, it effectively mitigates the pilot overhead catastrophe in highly dynamic scenarios and delivers significantly superior throughput performance compared to traditional fixed-window and global scanning schemes.
The Dawn of 6G: Empowering a User-Centric Ecosystem with Agentic AI
Joint Resource Allocation for Movable-Antenna-Assisted Secure Integrated Data and Energy Transfer
[Introduction] This paper investigates joint resource allocation for movable-antenna (MA) -assisted secure integrated data and energy transfer (IDET) systems with passive eavesdroppers. A field-response-based MA channel model is adopted to capture the impact of antenna positions on legitimate, energy-transfer, and eavesdropping links, while energy signals are reused as artificial noise for simultaneous wireless power transfer and secrecy enhancement. A max-min secrecy-rate problem is formulated by jointly optimizing information beamformers, energy beamformers, and MA positions under energy-harvesting, power, movable-region, and antenna-spacing constraints. To address the resulting nonconvexity, an iterative algorithm based on semidefinite relaxation, successive convex approximation, and alternating optimization is developed. Simulation results demonstrate that the proposed scheme improves the minimum secrecy rate compared with fixed-position antenna benchmarks while satisfying the energy requirements of energy receivers.