Improving ISAC System Long-Range Sensing with Alternating Cyclic Prefix and Postfix Signals

Integrated Sensing and Communication (ISAC) systems are pivotal in advancing B5G/6G networks, offering efficient resource usage and enabling diverse applications. However, ensuring optimal sensing performance alongside communication services in long-range scenarios remains a challenge. In this paper, we propose a novel signal structure tailored for longrange ISAC, integrating alternating Cyclic Prefix (CP) and Cyclic Postfix(CPost) Signals. This structure enhances detection probability, supports Frequency Domain Multiplexing (FDM), ensures compatibility with legacy User Equipment (UE), and enables adaptive Modulation and Coding Scheme (MCS) selection. We analyze the limitations of existing communication-based solutions and provide insights into potential approaches. Numerical results validate the efficacy of the proposed structure, demonstrating improved performance in terms of detection probability and Target Noise Ratio (TNR).