Collision Avoidance in V2X Communication Networks

TL;DR

This paper proposes a dynamic collision detection and avoidance scheme for full duplex vehicular networks, improving collision duration and throughput by adapting to SIC capabilities and outperforming fixed threshold strategies.

Contribution

It introduces a novel energy-based collision avoidance method that accounts for residual self-interference and dynamic thresholds, enhancing vehicular communication safety and efficiency.

Findings

Shorter collision durations with the proposed scheme

Better performance than fixed threshold strategies

Effective even with low SIC capabilities

Abstract

In this paper we investigate collision detection and avoidance in a vehicular network of full duplex (FD) operating nodes. Each vehicle in this network senses the energy level of the channel before and during its transmission. The measured energy is compared against a dynamic threshold which is preset based on the target detection probability, transmitter's power, sensing time and self-interference cancellation (SIC) capability of the vehicles' on board units (OBU). Probabilities of detection and false alarm, detection threshold before and during transmission, and effect of residual self interference (SI) on these metrics have been formulated. It is shown that the proposed scheme would experience a shorter collision duration. Meanwhile, it also requires a minimum SIC capability for acceptable operation, below which, system throughput would be poor due to high false alarm probability. Numerical simulations verify the accuracy of our analysis. They also illustrate that the proposed model perform better than the fixed threshold strategy. A trade-off between half duplex (HD) and FD has been found and the scheme would be applicable even if SIC capability of OBUs is relatively poor, with no need for complicated and expensive devices for future vehicular communication.