Research On Single Antenna Power Measurements Based Direction Finding Algorithm

Based on the characteristics of electromagnetic wave propagation and the antenna radiation pattern,the direction of arrival(DOA)of radio sources can be estimated.The techniques for DOA estimate have been discussed intensively in the literatures of signal processing.Because of its high-resolution,multiple signal classification(MUSIC)algorithm has caught a lot of attentions,and much efforts have been made to conque its computationally demanding problem.In practice,due to the requirements of antenna array,multi-channel receiver and continuous spectrum searching for DOA,the applications of MUSIC will be limited in some situations.Single antenna may be one of the convenient radio direction finding technologies.In this thesis,the method of direction finding by single antenna power measurements is discussed.We first model the antenna pattern as a finite sum of complex exponentials,then transform the task of DOA estimate from the received power measured at different directions into a frequency estimation problem.Finally the annihilating filter method is used to provide solution of DOA estimates.In terms of one or multiple DOA estimates of incoherent far-field sources,the following research work is included:Firstly,under ideal conditions and noise situations,simulation is made to validate the capability of DOA estimates using single antenna power measures.Secondly,the factors which may influence the performance such as the signal-noise ratio(SNR),beamwidth of antenna,the number of power measurements,the angle resolution and the number of radio,have been discussed and verified from the simulation results.Thirdly,a modified algorithm based on existing method has been proposed to improve the estimate accuracy.Comparisons were made between those two approaches.Furthermore,field experiments in an actual propagation environments were made to verify the feasibility of the proposed method.