Array Signal Processing and Spectrum Estimation.

The major emphases of the research proposal submitted to the Office of Naval Research in 1986 were in the development of new technique for coherent signal identification using multiple sensor elements and performance analysis of eigenstructure-based high resolution methods for direction finding. This research report concerns primarily with new development since the last report data in the detection of signals from measurements made at the output of a set of spatially deployed sensor element. Three key results that have obtained during this investigation is reported in section 2 with all details. To be specific, they are In the context of coherent signal classification, a spatial smoothing scheme first suggested Evans et al., and subsequently studied by Shan et al., is further investigated. It is proved in section 2.1 that by making use of a set of forward and complex conjugated backward subarrays simultaneously, it is always possible to estimate any K directions of arrival using at most 3K2 sensor elements. Section 2.2 presents a detailed asymptotic analysis of a class of high resolution estimators for resolving correlated and coherent plane waves in noise. These estimators are in turn constructed from certain eigenvectors associated with spatially smoothedor unsmoothed covariance matrices generated from a uniform array. Finally, a technique for estimating the directions of arrival of multiple signals utilizing the generalized eigenvalues associated with certain matrices generated from the signal subspace eigenvectors is proposed in section 2.3. RH