Passive Millimeter Wave Direction Finding Technology Based On Compressed Sensing

Millimeter-wave wireless communication or radar signals has characteristics of narrow-beam,low side-lobe and low-power,it has attracted more and more attention in the civil and military fields.The characteristics of millimeter-wave radiation sources pose difficulties to existing passive direction-finding techniques.To solve this problem,this paper combines the spatial sparse characteristics of radiating sources to study synthetic aperture millimeter-wave passive direction-finding techniques based on compressed sensing.The main work in this paper is divided into the following aspects:(1)This paper first introduces the theoretical basis of compressed sensing in detail,including the compression process and the reconstruction process under the compressed sensing framework.The sparse representation of spatial signals,the design of the observation matrix and the respective principles and characteristics of the four reconstruction algorithms are briefly introduced.Among them,the greedy algorithm and the convex optimization algorithm are mainly introduced.(2)This paper analyzes the direction finding of millimeter-wave radiation sources in space.Due to the characteristics of narrow-beam,low side-lobe,low-power and other characteristics of millimeter-wave sources,it has low interception characteristics.Conventional direction-finding methods are not effective.By referring to synthetic aperture technology,a synthetic aperture direction finding technique based on compressed sensing is proposed to solve the millimeter-wave passive direction finding problem,and a compressed sensing model of synthetic aperture passive direction finding is established.(3)In this paper,a reconstructed model with noisy measurement is established.The optimization model is adjusted by introducing a priori information or regularization parameters together with consideration of sparsity and noise suppression to facilitate accurate reconstruction,and simulation is performed to verify the effectiveness of the method.(4)At the end of this paper,the V band synthetic aperture radiometer is used to carry out the experiment.The theoretical derivation and the high performance reconstruction under noise measurement are analyzed and verified,so as to verify the feasibility of the new method.