Sources Parameters Estimation Based On Array Signal Processing

Arrays signal processing is based on an array of sensors with multi sensors in different spatial positions. By this space distributed array of sensors, spatial signal field is received, sampled and processed, characteristic information is obtained and disturb and noise is restrained effectively. Consequently multi dimension information of the signal in time field and in spatial field is obtained; signal testing and parameter picking up are achieved. The problem of source parameter estimation in the environments of far-field and near-field is considered in this paper based on arrays signal processing. The status of source parameter estimation is summarized and the new methods for source parameter estimation are proposed.Source parameter estimation is important in array signal processing. The traditional algorithm is to compute and decompose the covariance matrix. Because of its decomposition characteristics, the algorithm for Multistage Wiener filters does not require to obtain and decompose the covariance matrix. Signal subspace and noise subspace are obtained by nesting decomposing computation in the process of source parameter estimation, and the computational complexity decreases obviously. The characteristics of Multistage Wiener filters are analyzed in this paper. Sources numbers and source parameter estimation are studied for 2D arrays such as uniform circular array, uniform planar array and cross array in the additive noise environments. A fast method for parameter estimation based on Multistage Wiener filters of forward decomposition characteristic is proposed. Methods for 2D ESPRIT parameter estimation based on Multistage Wiener filters are also proposed. Without covariance array estimation and decomposition this kind of methods has the advantage of low computational complexity. An algorithm for sources numbers estimation is analyzed.Polarization is the inherent characteristic of the spatial electromagnetic wave and it can provide the movement characters of it. The direction of arrival and polarization are important character parameters of space electromagnetic wave. When multi signals much closely in space can not be distinguished effectively, they can be separated in polarization field by their polarization difference. An Algorithm for jointly source parameter estimation by polarization sensitive array has the advantage of high resolving power of array signal processing system and high capability of spatial spectrum estimation. A method for source parameter estimation of polarization sensitive array in near field is discussed by high order cumulant and then is proposed. By this method many parameters such as carrier frequency, azimuth, ranging and polarization etc. can be estimated synchronously and can be obtained directly without spectral peak searching. Contract with traditional algorithms, the number of the array's sensors and its hardware cost decrease. Its effectiveness is illustrated by the simulation results.By the analysis of flexibility and blind Gaussian characteristic of high order cumulant, the orientation problem in the 2D near field is studied; a root MUSIC algorithm based on four order cumulant pretreatment is proposed. Some simulation examples show the validity of this algorithm in the 2D near field. The azimuth and ranging in the near field can be estimated no needing of spectral peak searching. Contract with the presented method for 2D source parameter estimation, the proposed method has the advantage of low computational complexity by overcoming the disadvantages of searching calculation. The Gaussian white noise and color noise can be restrained effectively by four order cumulant.The main creative contents in this paper includes:An algorithm for 2D source parameter estimation based on MSWF is proposed to decrease the computation complexity of source parameter estimation under a 2D array of sensors without the computation and decomposition of covariance matrix. And the method for sources numbers estimation is proposed too. The simulation results based on 2D array such as uniform circular array, uniform planar array and cross array etc. illustrate that the sources numbers and source parameter can be estimated, thereby having the advantage in precision and computational complexity.The second, an algorithm for jointly source parameter estimation in spatial near field by polarization sensitive array is presented. Contracted with traditional algorithm, the parameter can be obtained directly, the number of array's sensors decreases. At the same time, it also has the merits of no needing spectral peak searching and low hardware cost.At last, by the analysis of flexibility and blind Gauss characteristic, a root MUSIC algorithm based on four order cumulant pretreatment is proposed, and overcomes the disadvantages of searching calculation. Contracted with the presented nonlinear optimal algorithm, by four order cumulant the proposed algorithm needn't complex computation, can restrain the Gauss white noise or color noise, and resolves the contradiction between good estimate precision and computation complexity in near field parameter estimation.