Automotive MIMO OFDM radar: Subcarrier allocation techniques for multiple-user access and DOA estimation

This paper presents the analysis of the spectrally interleaved OFDM signal used for the system concept of the MIMO OFDM Radar for automotive applications at 24GHz. The purpose of such a signal model besides the conventional sensing capability is twofold - 1) to enable multiple-user access and communication, 2) to accomplish angle estimation for object positioning by exploiting spatial diversity. There are however challenges associated with such a signal model in a multi-user and multi-path environment, which will incapacitate the radar's sensing capabilities. The signal model implemented in a full radar system simulation is analyzed in this paper and the possible solutions are then presented.