Integrated Sensing and Communication via Orthogonal Time Frequency Space Signaling with Hybrid Message Passing Detection and Fractional Parameter Estimation

Abstract

For the orthogonal time frequency space (OTFS) modulation, we generally multiplex symbols on a new type of carrier waveform in the delay-Doppler (DD) domain. These two parameters can be used to infer the range (R) and velocity (V) of the communication user and sensing target; thus, it is natural for the OTFS to be implemented in integrated sensing and communication (ISAC). A framework for ISAC based on OTFS modulation is proposed in this paper, in which the matched filter scheme with fractional parameter estimation is implemented for radar sensing. In addition, the hybrid message passing (MP) detection algorithm is developed for OTFS symbol demodulation. According to the simulation results, fractional DD shifts associated with multiple targets can be accurately obtained through the proposed framework. Meanwhile, the bit error rate under the proposed detector is less than 10−4 when the signal-to-noise ratio is high enough.

ISAC towards 6G Satellite–Terrestrial Communications: Principles, Status, and Prospects

“…The authors of [48] used OTFS for ISAC-assisted receiver design and utilized the novel deep residual denoising network framework to achieve effective channel estimation, which has higher performance and system robustness. An ISAC framework based on OTFS modulation was proposed in [49], which adopts a matched filter radar sensing scheme based on fractional parameter estimation to achieve better BER and estimation performance. In addition, in [50], the authors proposed the novel universal frequency multi-carrier waveform and compared it with the conventional OFDM.…”