Low‐Complexity DOA Estimation: Combining VSSLMS With FFT Spectrum Estimation

ABSTRACT Direction of arrival (DOA) estimation algorithms, such as multiple signal classification(MUSIC) and variable step size least mean square (VSSLMS), often encounter significant challenges due to their high computational complexity, which arises from the large sample sizes required for spatial spectrum estimation (SSE). In this letter, we propose a low‐complexity DOA estimation method. Initially, coarse estimates of the DOA are obtained using fast fourier transform (FFT), which are then refined within a localized region. Compared with existing SSE‐based algorithms, the proposed method reduces computational complexity by substituting the dominant term O ( ML ) with O ( M log L ), while simultaneously improving DOA estimation accuracy. Simulation results validate the efficacy of our method.This study employs a low‐complexity spectrum estimation method that ensures high accuracy while maintaining low complexity, making it suitable for hardware implementation and practical applications.