基于时间反转的非均匀线列阵超指向性阵元分布模型

以目标信号为前提，建立了基于时间反转(TR)的非均匀线列阵(NLA)的设计模型；采用均匀浅海多径信道的经典射线理论，以直达路径信号分量的时延为参考因子，推导了NLA的TR聚焦性能及方向图的影响因子.仿真结果表明，基于TR的NLA设计通过TR自适应修正多径信道传输时延的特性，不但克服了多径信道对目标方位估计(DOA)的影响，且提高了低信噪比下的DOA准确性，其方向图特性F(θ)与信号频带、阵列排布di、多径数目M以及快拍数K有关.基于7阵元分布的NLA方向图仿真结果相比均匀阵列具有超指向性，且在信噪比-6和-13 dB下均准确估计出目标方位.

Super-Directional Element Distribution Model of NLA Based on TR

The establishment of a designed model was discussed based on time reversal(TR) of non-uniformed linear array(NLA) as a precondition of the target signal. By using the multi-path channel classic ray theory under symmetrical shallow water environment, and adopting the line of sight signal components as a reference factor, the impact factor of NLA’s TR focusing performance and directional diagram was derived. The conclusion shows that the designed model not only overcomes multi-path channel influence, but improves direction of arrival(DOA) accuracy under low signal-to-noise, based on TR adaptive correction characteristics of multi-path propagation delay, while the directional diagram F(θ) is related to bandwidth, arrayed factor di, multi-path M and snapshots K. The simulation results show that directional diagram of 7 elements distribution NLA has super-directivity compared to uniformed linear array via TR, and accurately estimates the target orientation under both -6 dB and -13 dB signal-to-noise condition.