An Experimental Proof of Concept for OFDM-based ISAC System Utilizing Stepped-Carrier and TDM MIMO scheme

The problem with orthogonal frequency-division multiplexing (OFDM)-based integrated sensing and communication (ISAC) system is that the bandwidth required for high range resolution cannot be obtained. This problem can be overcome by using a stepped-carrier method, where the carrier frequency of each OFDM signal increases linearly to achieve wide overall RF bandwidth. In this article, for the first time we present a proof of concept for OFDM-based ISAC system utilizing both stepped-carrier and time-division multiplexing (TDM) multiple-input and multiple-output (MIMO) schemes. We propose time domain radar response estimation and target detection algorithms applicable to stepped-carrier TDM MIMO systems and provide the detailed description of the testbed implementation and setup. We also present experiment results in the millimeter wave band to validate the proposed algorithm and implemented system.