MIMO radar for direction finding with exploitation of time-frequency representations

In this paper we consider the exploitation of spatial time-frequency distribution (STFD) in multiple-input multiple-output (MIMO) radar systems. STFD has been found useful in solving various array processing problems, such as direction finding and blind separation, where nonstationary signals are involved. Such treatment has been primarily limited to traditional array processing whereas its use in MIMO radar scenario has received less attention. The emphasis of this paper lies in the reexamination of the STFD framework in an MIMO radar platform for the processing of maneuvering targets with nonstationary signatures. Within this framework, we consider the use of joint transmit and receive apertures for the enhancement and improved estimation of time-frequency signature and the application of STFD in joint direction-of-departure (DOD) and direction-of-arrival (DOA) estimations. As a result, it becomes clear that STFD is effective in MIMO radar processing when the targets are of signatures that are highly localized in the time-frequency domain.