DOA Estimation of Signals Using Fourth-Order Cumulant Method

In this document, we discuss Direction of Arrival (DOA) estimation of signals, a critical signal processing task. DOA estimation refers to determining the incident direction of signals, which plays significant roles in numerous practical applications including radar systems, sonar technology, wireless communications, and astronomical observations. We implement this objective using the fourth-order cumulant method - a statistical approach that estimates signal DOA by computing fourth-order cumulants of input signals. This technique has been extensively researched and applied, demonstrating robust performance across various system configurations. The implementation typically involves calculating fourth-order statistics using matrix operations, where key functions include cumulant matrix construction and eigenvalue decomposition for signal subspace identification. We believe this method constitutes an effective DOA estimation approach applicable to diverse practical scenarios, with MATLAB implementation potentially involving functions like cumest for cumulant estimation and MUSIC-like algorithms for direction finding.