Performance Optimization for STAR-RIS-Aided Integrated Sensing and Communication Systems

The simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) aided integrated sensing and communications (ISAC) framework holds promise for wide-range coverage, sensing, and communication. However, allocating multiple resources becomes challenging due to the coupled time, frequency, and space resources. Additionally, echo interference from communication users to the sensing target degrades sensing performance. To tackle these challenges, a performance optimization problem in a STAR-RIS-aided ISAC system is formulated, and an alternating optimization scheme is investigated to balance the defined sensing mutual information and communication performance by optimizing the active transmit beams, STAR-RIS reflecting and transmit beams, and multicarrier distribution variables under the energy splitting protocol. Simulation results demonstrate the convergence and effectiveness of the proposed scheme, highlighting its advantages in improving sensing performance compared to benchmark schemes.