Target Localization And Signal Detection For Frequency Diverse Array Radar Based On Information Geometry

Frequency diverse array(FDA)radar is a new radar system whose beam pattern is angle-range-dependent.Because there is a very small frequency offset between adjacent elements on the transmitting array.This is different from phased array(PA)whose beam pattern is angle dependent.The angle-range-dependent beam pattern of FDA radar provides a great potential in target localization and signal detection.To analyze the problems of FDA radar target localization and signal detection,information geometry theory is applied in this thesis.Information geometry is a new method that analyzes probabilistic problem by means of modern geometry.Uniform linear frequency diverse array cannot be directly used in target localization because range and angle parameters are coupled in signal peak.While FDA-MIMO radar can overcome the coupled problem.And this thesis focuses on target localization resolution analysis and signal detection scheme based on information geometry method.The main work and contributions of this thesis are:(1).The fundamentals and characteristics of uniform linear frequency diverse array is analyzed.The signal model of FDA-MIMO radar before matched filtering and matched filtered signal model is introduced.And the probability model of FDA-MIMO radar considering Gaussian white noise is introduced.(2).The basic principles of information geometry theory are summarized.As an inspiring example of information geometry method application in radar signal processing,the information resolution of pulse radar is introduced.It shows the unique advantages of information geometry in analyzing probabilistic problem in radar signal processing.(3).The resolution of FDA-MIMO radar is analyzed by means of information geometry method,and target localization scheme based on information geometry is provided.To analysis resolution of FDA-MIMO radar,the signal model of FDA-MIMO radar before matched filtering is used first.Different from traditional resolution analyzing method such as radar ambiguity function,noisy influence is considered,and the differential equations of geodesic of statistical manifold consisted of Gaussian probability functions is deduced.Because the solutions of the differential equations are hard to be simulated and information resolution of FDA-MIMO radar before matched filtering is related with waveform,the geodesic length on the manifold is replaced with Kullback-Leibler divergence(KL divergence),and matched filtered signal model of FDA-MIMO radar is adopted.KL divergence resolution and KL resolution cells are proposed.The KL divergence resolution provides a geometric perspective to the resolution analysis of FDAMIMO radar.Simulation examples confirm that KL divergence resolution is available in analyzing the resolution of FDA-MIMO radar.And the influence of parameters of FDAMIMO radar to its KL divergence resolution is analyzed.Inspired by KL resolution cells,a target localization scheme is proposed.(4).To study the signal detection problem of FDA-MIMO radar,this thesis states a traditional method based on generalized likelihood test(GLRT)and proposes a method based on information geometry theory.By means of GLRT,the single-frame detection method and multiple-frame detection method are derived.According to information geometry,the geometric interpretation of GLRT is shown.And a signal detection method based on information geometry is proposed.The detection performance of phased-array radar,FDA radar,MIMO radar and FDA-MIMO radar are compared,and conclusions show that the detection performance of FDA-MIMO radar achieves the state of art.This thesis takes advantage of information geometry and applies it on the problem of target localization and signal detection of FDA-MIMO radar.The proposed KL divergence resolution in this work provides a geometric view on the resolution of FDAMIMO radar based on the probabilistic model of matched filtered signal model of FDAMIMO radar.It is a new attempt for application of information geometry in FDA-MIMO radar signal processing.