Researches On Robust Spectrum Estimation Algorithms

An important research field in modern signal processing is the research of robust parameter estimation techniques. High resolution direction-finding method using array signal processing technique plays a pivotal role in the new electronic reconnaissance satellite system. This dissertation devotes to explain the theory of spectrum estimation and put the emphasis on researches of robust direction-of-arrival estimation algorithms. At first the classical direction-finding algorithms in array signal processing are introduced, some of them are simulated. Secondly, some high resolution direction-finding algorithms using Doppler-shifts are discussed and a modified space-time two-dimensional high-resolution isolated-dimensional estimation method is presented and its effectiveness is confirmed by computer simulations. As Doppler-shifts are widely exists in satellite communications, we attempt to discover how much of them will be caused while satellite moves. At the end of this paper some direction-finding and aperture extension algorithms by cumulants are emphatically researched and a colligate direction-of-arrival estimation scheme suits to deformed uniform circular arrays is presented.