Sensing-Communication Co-Design for UAV Swarm-Assisted Vehicular Network in Perspective of Doppler

Utilizing the unmanned aerial vehicle (UAV) swarm to realize sensing and communication for ground vehicles (GVs) has been envisioned as a promising technology in harsh environments. Previous research in vehicular networks has ignored or assumed perfect elimination of Doppler, resulting in unstable or impractical dynamic system models. However, Doppler is essential for multidimensional sensing, especially for velocity estimation, but it may lead to loss of signal-to-noise ratio (SNR) in communication. In this case, to achieve satisfying sensing and communication performance simultaneously, we propose a sensing-communication co-design scheme for UAV swarm-assisted vehicular networks in perspective of Doppler. We first establish the mathematical models for the effect of Doppler on communication and sensing respectively. Then we analyze the influence of UAVs link selection on GV sensing-communication performance. Based on this framework, we aim to minimize the GVs' maximum Cramer-Rao lower bound (CRLB) for sensing estimates with an SNR loss constraint to make a sensing-communication performance trade-off. Finally, an efficient differential evolution (DE)-based algorithm is developed to find a sub-optimal solution for this complicated non-convex problem. Numerical results demonstrate the validity and superiority of our co-design scheme. Compared with the state-of-the-art methods, our scheme can not only improve the sensing accuracy by more than 30% while ensuring communication, but also outperform over 20% in communication without sacrificing sensing capacity.