A fast high-performance array processing technique for angle-of-arrival estimation and detection of the number of incident signals

A new projection-based algorithm is proposed for estimating the angles of arrival of plane waves incident onto arrays of sensors. The method is based on a single QR decomposition of the signal covariance matrix; hence, it is much faster than eigen-based methods, which require many QR decompositions. It is shown that optimum performance is attained only if the columns of the covariance matrix are permuted in a prescribed manner before the QR decomposition proceeds. An adjunct to the angle-of-arrival estimation process is a new eigenvalue-free technique for estimating the number of incident signals. The performance penalty associated with these new methods is insignificant. The real-time performance of this technique is enhanced through the use of systolic arrays. A novel systolic array structure is proposed for extracting both the Q and R matrices generated by the QR decomposition.