Tracking and Transmission Design in Terahertz V2I Networks

This paper designs the vehicle tracking and resource allocation in the terahertz (THz) vehicle-to-infrastructure communications (V2I) networks, where roadside units (RSUs) equipped with leaky-wave antennas help to estimate the driving states of multiple vehicles and optimize the transmit power andbandwidth per vehicle after receiving the vehicles’ feedback. Different from the conventional phased arrays, the leaky-wave antenna has the potential of improving the sensing accuracy with lower system overhead thanks to its unique spatial-spectral coupling feature. The generalized mobile scenario is studied in which vehicles drive at time-varying speeds. A novel unscented Kalman filter (UKF) based solution is proposed to track the vehicles without requirement of addressing the Doppler effect. Based on the estimated states of multiple vehicles, a low complexity resource allocation method is developed to maximize the sum rate under user fairness concern. Simulation results confirm that the proposed tracking solution can evaluate the propagation angle, vehicle’s states and inter-vehicle distance accurately, and the tailored resource allocation method strikes a delicate balance between the sum rate and user fairness in the multi-vehicle V2I scenario.

本文针对太赫兹（THz）车路通信（vehicle-to-infrastructure communications, V2I）网络中的车辆追踪与资源分配方案展开设计。其中，配备漏波天线（leaky-wave antenna）的路侧单元（roadside units, RSUs）可在接收车辆反馈后，估算多辆车辆的行驶状态，并优化每辆车的发射功率与带宽资源。与传统相控阵不同，漏波天线凭借其独特的空谱耦合特性，具备以更低系统开销提升感知精度的潜力。本文研究了车辆以时变速度行驶的通用移动场景，提出一种基于无迹卡尔曼滤波（unscented Kalman filter, UKF）的新型车辆追踪方案，无需处理多普勒效应即可实现车辆状态追踪。基于多车辆的估算状态，本文设计了一种低复杂度资源分配方法，在兼顾用户公平性的前提下最大化总传输速率。仿真结果表明，所提追踪方案可准确估算传播角度、车辆状态及车间距离，而定制化的资源分配方法可在多车辆V2I场景中实现总速率与用户公平性之间的精准平衡。