Can Pilots be used for Integrated Sensing and Communications?
Invited talk, Seventh International Conference on Soft Computing and its Engineering Applications - December 09-11, 2025 | Hanoi, Vietnam | Hybrid Conference, Virtual
Abstract: Integrated sensing and communications (ISAC) systems for 6G promise to unlock unprece- dented efficiencies by merging wireless connectivity and target detection into a single platform. In this talk, we present a novel orthogonal pilot design for multi-user communications and target sensing in ISAC scenarios. Our approach begins with a mutual information (MI) analysis for both sensing and communication links, in addition to motivations and connections to channel capacity and probability of detection. Then, we formulate a multi-objective optimization problem (MOOP) that aims to simul- taneously maximize sensing and communication MIs. To manage this joint optimization, we simplify the MOOP into a single-objective formulation that reveals the inherent trade-offs between sensing and communication performance. Leveraging the projected gradient descent method on the Stiefel manifold, we derive closed-form gradient expressions that allow an efficient implementation of the algorithm. We demonstrate that our design significantly impacts communication performance while preserving strong target detection capabilities, showcasing by notable improvements in probability of detection for a fixed false-alarm probability. Moreover, we observe an information overlap phenomenon, highlighting how the inherent synergy in ISAC systems can be fully exploited.