Mobility-Aware Power Control and User Scheduling for Downlink V2I Networks

Vehicle-to-infrastructure (V2I) network is a new paradigm of wireless system with special topology where roadside units (RSUs) are linearly deployed along the roadside and vehicles linearly move on the road. For such system, some classical problems would have new formulations and solutions. We in this paper investigate the joint power control and user scheduling problem for a multi-cell downlink V2I network, the objective of which is to maximize the sum-rate of the network under the signal-to-interference-plus-noise ratio (SINR) constraint of each V2I link. Considering the high mobility of vehicles, the objective function is set as the mean of the sum-rate over a sequence of time slots. For ease of handling, we first decouple the problem into multiple separate subproblems based on the linear distribution of RSUs. Then we employ the quadratic transform technique for fractional programming (FP) to transform the mixed integer nonlinear programming (MINLP) subproblems into convex problems, and obtain the solutions with Branch and Bound method. Finally the validity of our proposed algorithm is verified by numerical simulations.

I. Introduction

Vehicle-to-infrastructure (V2I) communication, which can improve the road safety and traffic efficiency by information exchange between vehicles and roadside units (RSUs), is one of the promising solutions for the intelligent transportation systems (ITS). With the aid of V2I communication, a series of Assisted Driving (AD) applications are enabled, e.g., curve speed warning, red light warning, stop signal warning, pedestrian warning, etc [1]. In view of the wide application foreground, both the Dedicated Short Range Communications (DSRC) and the cellular vehicle-to-everything (C-V2X) standard have launched the research of V2I networking [1], [2].