Threshold performance analysis of maximum likelihood DOA estimation

The purpose of this paper is to investigate the nonasymptotic behavior of the maximum likelihood method in the context of lacunar array processing. We derive an analytical expression of the maximum likelihood mean square error, which is now valid for all signal-to-noise ratio (SNR) ranges. We also provide an analysis of the SNR threshold phenomena, which allows us to derive closed-form formulas for the threshold values. Computer simulations confirm the validity of the theoretical investigations.