Frequency Comb MIMO OFDM Radar With Nonequidistant Subcarrier Interleaving

To overcome the necessity of high sampling rates for common orthogonal frequency-division multiplexing (OFDM)based radar waveforms with a good range resolution, a scheme called frequency comb OFDM radar has recently been proposed. It keeps the sampling rates at the transmitter and receiver constant while simultaneously increasing the signal bandwidth in the radar channel. This letter describes the extension of the scheme for multiple-input multiple-output (MIMO) applications where a nonequidistant subcarrier interleaving can be used to prevent a reduction of the unambiguous range that occurs in case of regular allocation to the transmit channels. The functionality is demonstrated for the first time with a 4×4 MIMO system in a measurement scenario with static and emulated moving targets.