Adaptive detection and sidelobe signal rejection for MIMO radar

Antenna beam pattern in MIMO radar systems, like any other radar, exhibits sidelobes. Naturally it is possible for clutter and other sort of interference to be detected accidently via these sidelobes. This has the effect of mis-aligning the main beam steering vector and reducing detection performance. In addition, the performance is dependent on the precision of the array calibration process. This paper examines the competing effects of both those components. Specifically, we examine adaptive processing that operates across the whole MIMO system aiming to reduce sidelobe clutter, restore the steering vector to its true position and hence maximize signal to clutter ratio and therefore detection performance. The MIMO version of an Adaptive Detector with Conic Acceptance and Rejection (ADCAR) is developed, resorting to a generalized likelihood ratio principle. Constant False Alarm Rate (CFAR) properties of the detector are demonstrated. The performance of the MIMO- ADCAR is numerically evaluated. The results show the proposed detector is capable of achieving a compromise between sensitivity of mainlobe signal and rejection of sidelobe signal.