Outage Analysis of Platoon-Head Selection for Vehicle Platooning in V2X Networks

Abstract

This study analyzes the packet-outage performance of platoon-head selection for vehicle platooning in vehicle-to-everything (V2X) networks. A handover platoon head (H-PH) provides measurements for group handover, whereas a communication platoon head (C-PH) relays downlink packets. We derive serving-state-averaged outage expressions for three half-duplex decode-and-forward C-PH selection modes and for direct base-station (BS) groupcast under log-normal shadowing and Nakagami-m fading. For block-level selection, an exact tail formulation reduces an N-dimensional shadowing expectation to a single integral. In a five-vehicle scenario with a 50-Mb/s target rate and the leading vehicle midway between two BSs, direct groupcast yields an outage probability of 0.269, whereas the block- and slot-level relay-selection modes yield 0.144 and 0.0459, respectively. Moving the H-PH from the leading to the middle vehicle reduces slot-level outage by 12.0%. These results highlight the reliability benefits of H-PH placement and dynamic relay selection, as well as the potential gain of rapid intra-platoon channel state information sharing.