Unified Chirp Sequence Generation for OFDM-based ISAC System with TDM/FDM/CDM Resource Mul...

Integrated sensing and communication (ISAC) is an important new research topic for 5th-generation communication-Advanced (5G-A) and 6th-generation (6G) mobile communication systems, where waveform design should be studied. Orthogonal frequency division multiplexing (OFDM) is anticipated to be more favorable in the future 5G-A and 6G ISAC systems due to its good 5G New Radio (NR) backward compatibility. Different resource multiplexing methods, including time-division multiplexing (TDM), frequency-division multiplexing (FDM), and code-division multiplexing (CDM), for sensing and communication can be assumed in the OFDM-based ISAC system. Due to the low peak-to-average power ratio (PAPR) and good ambiguity function properties, chirp sequence can be used for sensing in the OFDM-based ISAC system. This paper proposes a unified chirp sequence generation method for OFDM-based ISAC system. By parameter configuration, different resource multiplexing methods of sensing and communication, including TDM, FDM, and CDM, can be realized based on the proposed method. Evaluation results demonstrate that the proposed chirp sensing sequence achieves better PAPR performance for both TDM and FDM methods and lower sidelobe level of the ambiguity function for TDM compared to OFDM with Zadoff-Chu (ZC) sequence, which indicates that the proposed chirp sequence with TDM and FDM can be considered as a suitable sensing sequence for scenarios with coverage limitations.

Unified Chirp Sequence Generation for OFDM-based ISAC System with TDM/FDM/CDM Resource Multiplexing

Juan Liu, DOCOMO Beijing Communication Laboratories Co., Ltd.; Wenjia LIU, DOCOMO Beijing Labs; Xiaolin Hou, DOCOMO Beijing Communications Laboratories Co., Ltd; chen lan, DOCOMO Beijing Communications Lab