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Abstract: Parameter estimation methods have wide applications in signal processing, communication and system identification. This paper derives an iterative least squares algorithm to estimate the parameters of output error systems and uses the partitioned matrix inversion lemma to implement the proposed algorithm in order to enhance computational efficiencies. The simulation results show that the proposed algorithm works well. [Copyright &y& Elsevier]

Abstract: The Fiedler vector of a graph is the eigenvector corresponding to the smallest non-trivial eigenvalue of the graph''s Laplacian matrix. The entries of the Fiedler vector are known to provide a powerful heuristic for topology inference, e.g., to identify densely connected node clusters, to search for bottleneck links in the information dissemination, or to increase the overall connectivity of the network. In this paper, we consider ad hoc networks where the nodes can process and exchange data in a synchronous fashion, and we propose a distributed algorithm for in-network estimation of the Fiedler vector and the algebraic connectivity of the corresponding network graph. The algorithm is fully scalable with respect to the network size in terms of per-node computational complexity and data transmission. Simulation results demonstrate the performance of the algorithm. [Copyright &y& Elsevier]

Abstract: In this paper, an algorithm for sparse channel estimation, called least-absolutes (), and an algorithm for equalization, called linear least-absolutes (LLA), in non-Gaussian impulsive noise are proposed. The proposed approaches are based on the minimization of the absolute error function, rather than the squared error function. By replacing the standard modulus with the of complex numbers, the resulting optimization problem can be efficiently solved through linear programming. The selection of an appropriate regularization parameter is also addressed. Numerical results demonstrate that the proposed algorithms, compared with the classical methods, are more robust to impulsive noise and have a superior accuracy. [Copyright &y& Elsevier]

Abstract: In this paper a new method for direction of arrival estimation of direct sequence code division multiple access (DS-CDMA) signals in multipath fading environments is proposed. The method is based on suppressing the effect of coherent signals from different paths by orthogonal projection of the antenna''s spatial-temporal output vector onto the undesired subspace. The method assumes the knowledge of the spreading code sequence and delays of the paths of the desired user and then applies the MUSIC algorithm with new transformed vectors. This method is applicable to all array geometries and does not need any spatial smoothing that is usually applied for coherent signals. The estimates of the proposed method are consistent and its performance is investigated through simulations. [Copyright &y& Elsevier]