Research On Integrated Direction-finding Technology Of Radar And Communication Signal

The concept of electronic warfare first appeared in the First World War,and in the Second World War,it has been widely used.With the development of electronic technology,many countries began to develop navigation system and radar system,so today electronic warfare not only includes the communication countermeasure,but also the navigation countermeasure and the radar countermeasure.The scope of the electronic warfare not only includes the land and the sky but also the ocean and the outer space.It plays an important role in a war,and the change has promoted countries to research the integrated electronic warfare of the radar and communication.At present,foreign countries have made some achievements in this field.Although we have made outstanding progress in communication countermeasure and radar countermeasure,in the integration of the two studies,we still don't have enough progress.The main work of this thesis is to study the integration direction finding algorithm of radar and communicaton signal.The main contents can be summarized as follows:Firstly,the general design of the integrated direction finding system is introduced,and the main modules and the functions of each module are introduced in detail.Then the operation timing diagram of the integrated direction finding system and the design of the PDW are given,which describe the running timing and the data interaction between the modules.What's more,this paper studies the channelized receiving system based on the digital filter bank.And the LFM signal is taken as an example to study the detection and recovery technology of the broadband cross channel signal.Finally,the classical signal number estimation algorithm is introduced.Secondly,the classical direction finding algorithms have been studied.We have studied and simulated the typical algorithms of phase interferometer direction finding algotithm,multi-beam direction finding algorithm and spatial spectrum direction finding algorithm.Then,we compare the direction finding performance and the direction finding efficiency of all the three algorithms.Thirdly,to solve the problem of amplitude and phase error correction of motion array,an amplitude-phase error correction algorithm based on orthogonal subspace is proposed.The snapshots collected at different positions are used to estimate the amplitude and error vector.Fourth,the integrated direction finding algorithm has been studied.And in order to evaluate the accuracy of direction finding,the concept of direction finding confidence is introduced.Finally,the block diagram of the integrated direction finding algorithm is given,and the advantages and disadvantages of each algorithm are introduced respectively.The algorithms are combined to realize the integrated direction finding based on the number of the direction signal and the judgment criterion of the direction finding.Fifth,In order to demonstrate the performance of the integrated direction finding algorithm better,we develope the simulation software,a set of demonstration system which is written by MATLAB,to demonstrate the algorithm.And the demonstration module,simulation interface and system settings and other functions are introduced detailedly.Finally,some simulation examples are given to illustrate the effectiveness of the integrated direction finding algorithm.