Integrated Sensing and Communications System With Multiple Cyclic Prefixes

This letter proposes an integrated sensing and communications (ISAC) system with multiple cyclic prefixes (CPs) to achieve effectiveness of ISAC in high Doppler scenarios. Multiple CPs include sensing CP and communication CP, which are prepended at the beginning of the transmitted signal and before each modulation symbol, respectively. For transmission, the introduction of multiple CPs obtains abundant maximum unambiguous Doppler by decoupling sensing and communication requirements. For sensing reception, a sensing parameter estimation method is developed which achieves robustness to Doppler shifts. Moreover, the multiple CPs are utilized to enhance sensing processing gain and reduce the complexity of sensing parameter estimation. Theoretical and numerical analyses reveal that the proposed system possesses robustness to Doppler shifts, high processing gain, reliable estimation accuracy and affordable complexity.