Novel beam former approach to direction-finding problem
Jeffrey Y. Byun, Stelios C. A. Thomopoulos · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1996
Estimation of the direction-of-arrival (DOA), also known as direction-finding (DF) problem, has been an active research area for some time. While one DOA estimation method may be better than another depending on the application, these methods can be categorized into either subspace decomposition methods or beamforming methods. Subspace decomposition methods are usually known to provide higher resolution but most of them assume relatively high signal to noise ratio. For low array-signal-to-noise-ratio (ASNR), however, their performance degenerates in a similar way as conventional beam forming methods do. In this paper, we introduce a new method which we refer to as 'MaxMax' method for ASNR below zero. The new method does not depend entirely on either the subspace decomposition technique or the conventional beamforming technique and is attractive for extremely low ASNR environment with small number of sensors at the price of higher computational complexity. Its performance is superior to the others for multipath signals for the same number of sensors. The number of signals need not be known and more than M-1 signals can be resolved where M is the number of sensors. The increased computational complexity can be reduced through parallel processing implemented on massively parallel computers.