OTFS-Aided Waveform Design for MU-MIMO Joint Sensing and Communication Systems

An orthogonal time frequency space (OTFS) modulation-based joint sensing and communication (JSAC) system is proposed. A multi-user multi-input multi-output (MU-MIMO) system is also considered for the JSAC system. OTFS can mitigate the channel-induced dispersion, while the OTFS signal has a low peak-to-average power ratio (PAPR). OTFS is a modulation scheme where delay-Doppler domain transmit grids are formed by appropriately mapping the constellation symbols. OTFS is capable of providing significant advantages in challenging scenarios with severe fading, delay spread, and Doppler shift. The proposed OTFS-based dual-functional wave-form optimizes spectral efficiency by sharing the same frequency band and enhances the overall performance of the MU-MIMO JSAC scheme. The performance of the OTFS-based MU-MIMO JSAC has been investigated in terms of ambiguity function, sum rate, and range-angle response. The proposed OTFS MU-MIMO JSAC provides remarkable performance compared to the traditional JSAC system.