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

Abstract

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 <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">QR</i> decomposition of the signal covariance matrix; hence, it is much faster than eigen-based methods, which require many <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">QR</i> 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 <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">QR</i> 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 <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i> and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> matrices generated by the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">QR</i> decomposition.