OTFS Radar Communication Integrated Multiplexed Waveform Design

‍ ‍As wireless communication technology advances， the overlapping of radar and communication frequency bands has become more pronounced. Integrating radar and communication systems emerges as a promising solution to mitigate the scarcity of spectrum resources. Orthogonal frequency division multiplexing （OFDM）， which is one of the main carriers of radar communication integration， can divide waveform design methods into two categories： one is the multiplexed waveform design， the other is the common waveform design. Common waveform design requires balancing radar and communication performance， necessitating special processing flows in both radar signal processing and communication reception. In cases where spectrum resources are abundant， the advantages of multiplexed waveform design based on OFDM become more apparent compared to traditional waveform designs. Due to the high sensitivity of OFDM to Doppler， the multiplexed waveform design based on OFDM is not suitable for high-speed motion scenarios. To solve this problem， this paper proposes a radar communication integrated multiplexed waveform design based on orthogonal time frequency space （OTFS）. This design used the high tolerance of OTFS Doppler to realize the integration of radar communication in high-speed motion scenarios. Considering the similarity of the delay-Doppler domain of OTFS and the fast time and slow time of radar， this study used Doppler multiplexing to realize an integrated multiplexed signal design and used the communication and radar receiver processing flow under this waveform. The communication receiver could realize high-speed communication through OTFS demodulation； the radar receiver did not need to perform waveform separation and could directly complete the target information estimation using the conventional radar signal processing process. In this study， the feasibility of the proposed integrated multiplexed waveform is verified by simulation， and the advantages of the proposed waveform in radar target parameter estimation and communication bit error rate compared with the OFDM multiplexed waveform in high-speed motion scenarios are verified through simulation.