Radar Sensing with OTFS: Embracing ISI and ICI to Surpass the Ambiguity Barrier

Orthogonal time frequency space (OTFS) is a promising alternative to orthogonal frequency division multiplexing (OFDM) in high-mobility beyond 5G communications. In this paper, we consider the problem of radar sensing with OTFS joint radar-communications waveform and derive a novel OTFS radar signal model by explicitly taking into account the inter-symbol interference (ISI) and inter-carrier interference (ICI) effects. On the basis of the new model, we show how ISI and ICI phenomena can be turned into an advantage to surpass the maximum unambiguous detection limits in range and velocity, arising in existing OFDM and OTFS radar systems. Moreover, we design a generalized likelihood ratio test based detector/estimator that can embrace ISI and ICI effects. Simulation results illustrate the potential of embracing ISI/ICI and demonstrate its superior detection and estimation performance over conventional baselines.This work was supported, in part, by Vinnova grant 2018-01929 and the Dutch Technology Foundation TTW, which is part of the Netherlands Organisation for Scientific Research (NWO), under the project Integrated Cooperative Automated Vehicles (i-CAVE)