Study On Multidimensional Parameter Estimation For Near-Field Sources

Estimation of the direction-of-arrival (DOA) of the multiple signals,as arepresentative technique in estimation of signal parameters, is an important researchdirection and one of the two basic topics of array signal processing. It has beenwidely used in some areas such as radar, sonar, communication, electronicsurveillance, seismic exploration. The traditional high-resolution algorithms forsolving the DOA estimation problem generally operate under the assumption that allsources are in the far field of the array and each signal received by the array hasplanar wavefront. However, when sources are located close to the array and in theFresnel region of the array aperture, the plane-wave approximation to the sphericalwave-fronts is no more valid, in which case near-field sources is introduced. Thisthesis deals with the multidimensional parameter estimation problem of frequency,range and DOA of near-field sources. A performance analysis of the fourth-ordercumulant based algorithms for estimating range and DOA of near-field sources ismade. When the frequency of a signal is unknown, the estimation problem of thenear-field sources can be extended to three-dimensional parameters estimation.Based on state-space like,A new algorithm for jointly estimating frequency, rangeand DOA of the near-field sources which can automatically make the parameterpairing is presented. Computer simulations show that the proposed algorithm canachieve a better and robust performance.