Multi-target direction finding in MIMO radar exploiting nested array

Abstract

In this paper, a novel multi-target direction finding approach is proposed for multiple input multiple output (MIMO) radar exploiting nested array. In our MIMO radar model, the transmit antennas are widely spaced to enable transmit diversity, while the receiver of the MIMO radar is configured with a 2-level nested array to enable direction finding. The nested array is an emerging non-uniform linear array (NLA) which can contain a large number of virtual sensors in MIMO radar system. When multiple targets are closely located in spatial domain, the proposed approach can significantly enhance the resolution and estimation accuracy relative to the conventional method with uniform linear array (ULA). In the proposed approach, no peaking searching is needed. Notably, it fits the situation that the number of targets is equal or even larger than that of the receive sensors, which is unavailable for the conventional MIMO radar system. The simulations validate the performance of the proposed approach.