Feedback Coding of URLLC in Vehicle-to-Everything (V2X) Communications and Its Secrecy Analysis

In the literature, channel feedback has already been shown to be an effective way to realize ultra-reliable and low-latency communication (URLLC). In this paper, we aim to extend the point-to-point Schalkwijk-Kailath (SK)-type noisy feedback scheme to Vehicle-to-Everything (V2X) communication scenario. Although enhanced mobile broadband (eMBB) and URLLC services are considered as key enablers for V2X communication, here we mainly focus on URLLC service due to the urgency nature of the practical transportation systems. To be specific, based on the SK-type noisy feedback scheme, we propose a finite blocklength feedback coding scheme for URLLC message by mitigating the interference of eMBB message through dirty paper coding. Then, we explore security performance of the proposed scheme by calculating the information leakage to the eavesdropper. Numerical results show that the blocklength of the proposed scheme is significantly short for the desired decoding error probability, and the proposed scheme almost meets the physical layer security requirement for some cases. The study in this paper provides a new method for the secure URLLC in V2X communication.