Noncoherent versus coherent MIMO radar for joint target position and velocity estimation

Recent research indicates that one can obtain improved MSE performance from employing a coherent processing approach in MIMO radar with properly placed antennas. This paper demonstrates that the magnitude of these gains decreases with an increase in the product of the number of transmit and receive antennas if the antennas for the noncoherent system are also suitably placed, using a placement which is generally different from the one for the coherent processing approach. In particular, the mean square error (MSE) of the noncoherent system approaches that of the coherent system when the product of the number of transmit and receive antennas is sufficiently large. A theorem is presented for the case of orthogonal signals in temporally and spatially white noise-plus-clutter, but numerical results for nonorthogonal signals and colored noise-plus-clutter follow a similar pattern.