A Rate-Splitting Multiple Access Enabled Cooperative ISAC Tracking System for Complex V2I Scenarios

As a promising technology in the B5G and 6 G era, integrated sensing and communication (ISAC) can simultaneously support high-quality sensing and communication, and there is a growing consensus to introduce this technology into vehicle-to-everything (V2X) networks. Meanwhile, deploying cloud radio access networks (C-RANs) enables cooperation among multiple base stations (BSs), further bringing about cooperative gains. However, the mechanism of ISAC-based multi-BS cooperative tracking is still unclear, and the moving VUs also pose significant challenges for multi-BS cooperative dynamic interference management. Driven by the above issues, this paper investigates a cooperative ISAC (Co-ISAC) tracking system that supports rate-splitting multiple access (RSMA) transmission strategies for complex vehicle-to-infrastructure (V2I) scenarios. First, we consider VUs with complex trajectories and design the system workflow based on the interacting multiple model unscented Kalman filter (IMM-UKF) framework and the theory of weighted least squares (WLS). Next, we investigate multi-BS joint transmission strategies based on single-carrier RSMA (SC-RSMA) and multiple-carrier RSMA (MC-RSMA). The latter is designed for more challenging wireless environments with a small number of antennas and adds to the former a grouping method based on graph theory and an inter-group power allocation method based on predicted state vectors suitable for dynamic scenarios. Finally, numerical results demonstrate that the RSMA-enabled Co-ISAC tracking system performs better than other baseline schemes in complex V2I scenarios.