Channel Modeling and Target Identification for FMCW MIMO Radar Using DDM and CFAR

This paper presents a detailed signal and channel model for FMCW (Frequency-Modulated Continuous Wave) multiple-input multiple-output (MIMO) radar systems using Doppler Division Multiplexing (DDM) while dealing with interference. DDM offers a simple way to separate transmitted signals in space, but interference from outside sources is still a major issue. We create a specific variable delay channel model that addresses both target and interference paths, considering two-way and one-way Doppler effects, respectively. The receiver setup features a three-stage FFT processing chain, standard cell averaging CFAR (constant false alarm rate) detection, and a DDM demultiplexer for the final target extraction. Simulations in both near- and far-interference situations show how effective the system is at reducing interference and accurately identifying targets. This highlights the reliability of the DDM-CFAR method in difficult spectral conditions.