OTFS-Based ISAC: How Delay Doppler Channel Estimation Assists Environment Sensing?

Environment sensing has become a crucial aspect of next-generation wireless networks. The orthogonal time-frequency space (OTFS) waveform, a recently introduced technique that harnesses the delay-Doppler domain for information transmission, exhibits significant potential to uncover the physical wireless propagation environments. In this letter, we develop an OTFS communication-based integrated sensing and communication (ISAC) framework to jointly estimate the target state and transmitter location by formulating a weighted least squares (WLS) problem, which can be accurately solved by semidefinite relaxation (SDR) technique. Besides, we treat the previously estimated target states as auxiliary information for sensing, making the proposed OTFS-based ISAC framework still effective even when the available receivers are inadequate. The effectiveness of the proposed OTFS-based ISAC framework is demonstrated by simulation results.