On the Performance of an Integrated Communication and Localization System: An Analytical Framework

Localization has become a prominent use case for 6G mobile networks, and the integrated localization and communication (ILAC) system represents an inevitable trend. To design and manage such ILAC systems effectively and efficiently, quantification of its performance bound, i.e., an analytical model that reveals the trade-off between communication and localization performance, is a crucial yet unresolved task. To address this, we proposed an analytical framework for an ILAC system that achieves communication and localization. Specifically, we derived a closed-form expression of the capacity loss versus localization Cramer-Rao lower bound (CRB) loss through time-domain and frequency-domain resource allocation. Through simulations, we validated our analytical model and observed that frequency-domain resource allocation is preferable in scenarios with fewer antennas at the next generation nodeB (gNB) and a larger distance between user equipment (UE) and gNB. Conversely, time-domain resource allocation is preferable in scenarios with more antennas and a smaller distance between UE and the gNB.