| No matter in residential areas or military realm, the high resolution methods ofparameters estimation all plays important roles on aspects of sources location,classify, tracking and so on. Both the spatial domain and the polarization domain ofparameters estimation of narrowband signals are concerned as main topics in thispaper. And the following aspects are researched in detail.First of all, after fully studied the conventional high resolution method ofparameters estimation by subspace decomposition, the advantages and disadvan-tages on the adaptive of generalized array geometry and the capability of estimatingparameters of coherent sources are analyzed. It is argued that a general method ofparameters estimation should be valid for sources with any correlation, and has noarray geometry constraint and also will not introduce effective array aperture loss.Based on this argument, a pretransformative MUSIC method which accords withthis demand is proposed after deriving the advantages of the MUSIC method and theDOA matrix method. And its performance is also concisely analyzed.Next, the polarization characteristics of electromagnetic wave signals are in-vestigated and an idea of improve the spatial filter performance of the pretrans-formative MUSIC method by using polar parameters is presented. This idea ismainly used to solve the problem that the spatial parameters of incidenting signalscan not be recognized when their differences are small. Partly polarized waves arecommonly appears in real propagation free space. Though methods for estimatingspatial and polar parameters of completely polarized signals are available, and alsoideas for using polar information to estimate spatial parameters of coherent signalsturn up, there is still no clear and useful literature available to estimate the mainpolar parameters of partly polarized waves. In order to solve this problem, this paperextends the method of spatial parameters estimation and come up with a usefultechnique on main polar parameters estimation of partly polarized waves. It isdemonstrated that this technique is useful for polar and spatial parameters estimationof complete and incomplete polarized waves with arbitrary correlation.Again, it is well known that not all of the signals impinged on array are desiredsignals. Based on the idea of reducing or removing the influences of the unwantedsignals, a method of interference suppression based on generalized obliqueprojection operators is proposed after theoretical analysis of the principle of theoblique projection filter. According to the second-order cone programming theory,the method of generalized oblique projection filter is expanded, and a low side-lobegeneralized oblique projection filter is designed. By using multiple generalized oblique projection filters, a multi-beam matrix pre-filter weight vector is given andfiltering regions of interest are covered. This filter can suppress interference ofout-selected areas automatically, and finally improve the performance of highresolution parameter estimation of desired signals with the minimal influences ofinterference.At last, a method of high resolution parameter estimation based on signals’sparse character is investigated after analyzing the sparse reconstruct theory. It isused to solve the disadvantage of the proposed spatial high resolution parameterestimation technique of the pretransformative MUSIC method which needs largesnaps. And the array data processing model of this method makes use of the fact thatthe incident angles of signals impinged on sensor arrays are sparse enough compar-ing with all the possible bearing angles. Theoretical analysis shows that this methodis also one kind of general methods of high resolution parameter estimation, and it isvalid for array with arbitrary geometry, and parameters of uncorrelated, partlycorrelated and even coherent signals can be estimated with small number of arraysnaps. |
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