Joint Beamforming and Deployment Optimization for UAV-Enabled ISAC Systems Under Statistical QoS Constraints

In this paper, an unmanned aerial vehicle (UAV)- enabled integrated sensing and communication (ISAC) system over Rician fading channel operating under statistical quality of service (QoS) constraints is investigated. Effective capacity (EC) is adopted to quantify the performance of data transmissions, which represents the maximal constant arrival rate while satisfying the statistical delay requirements. Assuming the UAV remains stationary, an optimization problem of jointly designing the transmit beamforming, sensing covariance matrix, and UAV location, while subjected to constraints of QoS, sensing and total transmit power, to maximize the weighted sum EC is formulated. To tackle with the non-convexity and non-linearity of the problem, alternating optimization (AO) is incorporated to decompose the original problem into two subproblems: the optimization of the transmit beamforming and sensing covariance matrix, and the design of UAV location. An algorithm is proposed to obtain a first-order optimal solution. Simulation results validate the superiority of the proposed scheme, particularly under stringent delay constraints.