Multi-Scatter-Point Target Estimation for Sensing-Assisted OTFS Automotive Communication

We consider radar parameter estimation for multiscatterer targets with an Integrated Sensing and Communication (ISAC) system employing a Hybrid Digital-Analog (HDA) architecture and Orthogonal Time Frequency Space (OTFS) digital modulation. To deal with the beamforming restrictions imposed by the HDA architecture, we investigate parameter estimation under a multi-block observation scheme and formulate this as two distinct variations of the Multiple Measurement Vector (MMV) framework. The Fast-Iterative Shrinkage Thresholding Algorithm (FISTA) is then used to solve the problem. Our numerical results demonstrate that using this technique, it is possible to reliably resolve a multi-scatter-point target and obtain an estimation of the target's geometric extent, which can be used for post-processing requirements such as tracking or orientation estimation.