Optimal time division multiplexing schemes for DOA estimation of a moving target using a colocated MIMO radar

Abstract

A Multiple-Input-Multiple-Output (MIMO) radar can achieve a higher accuracy in direction of arrival (DOA) estimation compared to a corresponding Single-Input-Multiple-Output (SIMO) radar due to its larger virtual aperture. If the target is moving relative to the radar, an additional phase shift is introduced into the baseband signal because of the Doppler effect. Hence the Doppler frequency has to be estimated in addition to the DOA. In general, this decreases the DOA estimation accuracy. We investigate MIMO radars using time division multiplexing (TDM). We derive the Cramer-Rao bound (CRB) for a moving target and a general TDM scheme and compare it to other radar systems. Moreover we derive optimal TDM schemes which minimize the CRB under different constraints.