单基地MIMO雷达稀疏阵列结构设计:基于邮票问题和嵌入子阵互质阵列OA

The unauthorized flight of unmanned aerial vehicles has become an increasingly frequent phenomenon in soci-ety.Featuring a low flight altitude,small volume,and small radar cross-section,such unmanned aerial vehicle targets present prominent low observability,which poses severe challenges to low-altitude supervision work.Nevertheless,the traditional multiple input multiple output(MIMO)radar structure is plagued by the drawbacks of a small aperture and low degree of freedom,making it difficult to meet the direction-finding requirements for such low-observability targets.Traditional MIMO radar structures suffer from limited aperture and low degrees of freedom(DOFs),making it difficult to meet the multi-target observation requirements.To address this issue,this paper proposes a design strategy based on the monostatic coprime MIMO radar structure from the perspective of the postage-stamp problem(PSP)to improve the direction of arrival(DOA)estimation performance.The construction process of the difference co-array of sum co-array(DCSC)generally consists of two steps:calculating the second-order sum co-array(SC)of the receiving and transmit-ting arrays,and constructing the DCSC.The proposed design strategy first models the step of calculating the SC as a PSP and arranges physical sensors according to the solution of the PSP.Second,it introduces an expansion factor to ex-pand the array aperture flexibly.Finally,it optimizes the expansion factor based on the principle of maximizing continu-ous DOFs.This study combines this design strategy with the padded coprime array to propose a padded coprime array-based MIMO radar.Simulation results verify the superiority of the proposed design strategy and MIMO radar structure in terms of DOA estimation.