Adaptive Keeping Probability Algorithm to Reduce Resource Collisions in LTE-V2X

Due to the characteristics such as the existence of periodic packets, LTE-V2X Mode 4 resource allocation utilizes sensing-based semi-persistent scheduling (SPS) to reduce resource collisions. In SPS, vehicles must determine whether to reselect resources based on the keeping probability when the counter reaches zero. We know that increasing the keeping probability can enhance the system’s overall reliability. However, it may result in prolonged resource collisions among local vehicles. To address this issue, we introduce an adaptive keeping probability algorithm based on SPS (AP-SPS) that adjusts the keeping probability based on the overlapped ratio of the selection window. This algorithm enables vehicles to adjust their keeping probability automatically and reduces resource collisions. In comparison to the SPS, the suggested AP-SPS has been shown to have a lower probability of resource collision in simulation with various settings.