Probabilistic resource rescheduling for C-V2X based on delivery rate estimation

Abstract

Vehicle-to-everything (V2X) communication is an essential component for fully autonomous vehicles in future intelligent transportation systems, and cellular-V2X (C-V2X) is a standard that allows vehicles to communicate with its surroundings using cellular technology. Among the resource allocation modes of C-V2X, Mode 4 is a distributed scheme in which each vehicle independently selects a radio resource using the sensing-based semi-persistent scheduling (SB-SPS) algorithm. However, it is susceptible to resource conflicts especially with increased vehicle density or mobility, and the conflicts cannot be detected, leading to poor performance due to collisions and interference. To address this problem, this paper proposes a delivery rate estimation based probabilistic resource re-scheduling (EB-PRS) scheme. The delivery ratio is estimated using opportunistic bloom filter-based feedback on which vehicle's messages are received successfully. Based on the estimated delivery rate, EB-PRS carefully reselects resources probabilistically to maximize performance. EB-PRS is evaluated in highway and urban scenarios using WiLabV2Xsim simulator to show that it significantly improves upon the SB-SPS by reducing packet collisions.