关键词: 宽带信号, 实值处理, 聚焦矩阵, 子空间投影, 计算复杂度

Abstract: In order to reduce the computational complexity and resolution threshold of classical TCT algorithm for wideband signals，the real value transforming process and an improved MUSIC method based on subspace projection are introduced for central symmetric arrays to propose a new direction finding method for wideband sources.In this method，firstly，noise removal and forward-backward smoothing are conducted on the data covariance matrices at different frequencies，then these matrices are transformed into real ones by left-real transforming matrix，which achieves a substantial reduction of computational load in later eigen-decomposition operations，next focusing matrices for different frequencies are computed by conventional TCT method to transform data covariance matrices into ones at a common 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 bias noticeably compared with conventional TCT method.

Key words: wideband sources, real value processing, focusing matrices, subspace projection, computational complexity