Efficient and Accurate Single-Snapshot DOA Estimation for Massive ULA via Enhanced ApFFT
摘要
Addressing the dual challenges of high computational complexity in traditional algorithms and spectral leakage in discrete Fourier transform (DFT)-based methods for single-snapshot direction of arrival (DOA) estimation in massive uniform linear array (ULA), this study proposes a rapid, high-accuracy DOA estimation algorithm that leverages the enhanced all-phase fast Fourier transform (ApFFT). The process begins with an initial estimation using enhanced ApFFT, which provides preliminary DOA estimates with higher accuracy compared to traditional algorithms based on DFT. Then, a refinement process involving a Taylor expansion of the steering vector and Newton iteration for angle offset adjustment follows. The initial estimation based on the enhanced ApFFT confines the estimated angles within a tighter range around the true DOA, enabling the optimization phase to yield exact estimates quickly. Simulation results confirm the superior performance of our algorithm over existing DFT-based methods and Root-MUSIC algorithm.