New real-space direction finding method for wideband sources

In order to reduce the computational complexity and resolution threshold of classical TCT method for wideband signals, the real value processing and an improved MUSIC method based on subspace projection are incorporated for central symmetric arrays to propose a new direction finding method for wideband sources. This method first transforms the complex data covariance matrices after noise removal and forward-backward smoothing at different frequencies into real ones by left-real transforming matrix, which achieves a substantial reduction of computational load in later eigen-decompositions; then resorts to classical TCT algorithm to compute focusing matrices for different frequencies and use them to align data covariance matrices at a reference frequency; finally the direction of sources are obtained by a series of one-dimensional search of the maxima of an improved MUSIC estimator based on subspace projection. Simulations show that the proposed method reduces not only the computational overhead but also the resolution threshold and RMSE remarkably.