For the problem of signal leakage into noise subspace using Multi-stage wiener filter (MSWF) technique to estimate the signal subspace

this paper presents a subspace estimation algorithm.This method does not require the training signal and pre-knowledge of source number.Then

a post detection method is proposed for the source number estimation.And the source number detection and DOA estimation can be simultaneously completed.The whole algorithm does not need computing covariance matrix and eigen-decomposition

so the complexity is greatly decreased.Compared with the classical eigen-value decomposition (EVD) based methods

the procedure has less computation complexity with the approximation performance in the simulation of uniform linear array and uncorrelated signals.The simulation results demonstrate its effectiveness.