Second-order moment-based direction finding of a single source for ULA systems

We address the problem of direction of arrival (DOA) finding for uniform linear arrays (ULAs). We derive a new and very simple method for estimating the DOA of a single source based on the covariance matrix of the received signal. The new method is non-data-aided (NDA) and does not therefore impinge on the whole throughput of the system. The noise components are assumed spatially and temporally white. The new method is derived in closed form and it exhibits exactly - over a wide practical SNR range - the same performance of the popular root-MUSIC algorithm, a powerful DOA estimation technique for ULA configurations. Therefore, the new estimator offers a way for a rapid and very easy DOA evaluation; making it very attractive for practical implementation as compared to the root-MUSIC algorithm that relies on the heavy operation of eigen decomposition.