A novel OFDM-MIMO radar with non-equidistant subcarrier interleaving and compressed sensing

A novel concept of orthogonal frequency division multiplexing (OFDM) multiple input multiple output (MIMO) radar for automotive applications is presented in this paper. Multiple transmit antennas are multiplexed via OFDM subcarrier interleaving. Such a multiplexing enables a simultaneous operation of transmit antennas, while the complete bandwidth is utilized by each of them. Whereas the known OFDM-MIMO radar concepts perform multiplexing via equidistant subcarrier interleaving, we propose the use of non-equidistant subcarrier interleaving for multiplexing of transmit antennas. The advantage of this approach over the equidistant interleaving is the full unambiguously measurable distance range, not reduced through the subcarrier interleaving. To cope with the increased sidelobes in distance estimation due to the non-equidistant subcarrier interleaving, we propose a novel two-dimensional distance-velocity estimation algorithm based on compressed sensing that incorporates the radar images from all antennas. The proposed algorithm is able to detect weak targets, originally masked by the sidelobes of more dominant ones.