초록 ▼

A Two-Stage Hybrid algorithm offers significant improvement in the false alarm rate and detection performance of Space-Time Adaptive Processing in non-homogeneous environments for both radar and digital communications. The first stage analyzes data from a range cell of interest by direct data domain

A Two-Stage Hybrid algorithm offers significant improvement in the false alarm rate and detection performance of Space-Time Adaptive Processing in non-homogeneous environments for both radar and digital communications. The first stage analyzes data from a range cell of interest by direct data domain processing, suppressing discrete interferers within the range cell of interest. The second stage implements a purely statistical STAP algorithm, preferably an enhanced version of the Joint-Domain Localized ("JDL") statistical algorithm. For radar this second stage estimates the interference within the range cell of interest from the surrounding range cells. For a communications system, the second stage estimates the covariance matrix of the interference from the entire data block. For both radar and communications, an adaptive filter that suppresses the interference is generated from the estimate by second-order statistics. The present invention is the first two-dimensional STAP technique; all prior-art is one-dimensional.

대표청구항 ▼

[ What is claimed is:] [15.]15. Apparatus for adaptive signal processing, which comprises:first selection means for selecting at least one primary cell from a plurality of signals by spatially and temporally sampling from said plurality;means for sequentially choosing a main angle-look direction and

[ What is claimed is:] [15.]15. Apparatus for adaptive signal processing, which comprises:first selection means for selecting at least one primary cell from a plurality of signals by spatially and temporally sampling from said plurality;means for sequentially choosing a main angle-look direction and a main Doppler in relation to said at least one primary cell;means for forming a steering vector based on said angle-look direction and said Doppler;first computing means for computing, for said at least one primary cell, a first set of adaptive weights based on said steering vector;first application means for applying said first set of adaptive weights to signals in said at least one primary cell to form a primary localized processing region ("LPR");second selection means for selecting from said plurality of signals a set of secondary cells associated with said at least one primary cell;second application means for applying said first set of adaptive weights to said set of secondary cells to form a plurality of secondary LPRs and to convert said steering vector to a LPR steering vector;means for estimating, from first interference statistics of said plurality of secondary LPRs, second interference statistics for said primary LPR;second computing means for computing a second set of adaptive weights from said second interference statistics and said LPR steering vector;third application means for applying said second set of adaptive weights to said primary LPR; andmeans for comparing a result from said third application means to a threshold value to determine presence or absence of a desired signal.