针对应用中存在的阵列幅相误差扰动问题,结合MUSIC(Multiple Signal Classification)算法,以均匀Y型阵列为基础,提出了一种针对幅相误差的校正及DOA(Direction Of Arrival)估计算法。先利用传统的MUSIC算法初步估计出信源的波达方向角,并计算出幅相误差的初始值,再通过迭代的方法计算得到更精确的幅相误差和DOA估计值。仿真实验验证了自校正算法具有良好的幅相误差校正效果,能够准确地估计出信源的波达方向和阵元的幅相误差值。
在具有循环平稳特性的信号环境中,传统DOA(Direction Of Arrival)估计算法精度很差,甚至失效。为此,将Cyclic-Music算法运用在MIMO(Moltiple Inpat and Multiple Output)雷达系统中,利用循环统计量理论计算接收信号间的循环相关函数,基于此构造循环互相关矩阵,并对其进行奇异值分解和谱峰搜索,从而得到信号的波达方向角。理论推导和仿真结果均表明,该方法可以有效估计具有循环平稳特性的人工信号波达方向,从有效性和精度两个方面改善了MIMO雷达的估计性能。
针对空间谱估计算法在实际应用中的误差问题,讨论了在存在阵列幅相误差背景下,多重信号分类法(MUSIC:MUltiple SIgnal Classification)测向算法在DSP(Digital Signal Processor)上实现的一种方法。通过设置方位精确的辅助阵元对幅相误差进行校正,辅助阵元的方位信息为误差参数的计算提供了必要的信息量,然后利用MUSIC算法进行波达方向估计,同时利用TI公司高速DSP芯片(TMS320C6713)实现了在阵列幅相误差背景下的MUSIC测向方法。仿真结果证明了该方法的有效性。
In the paper,polarization-sensitive array is exploited at the receiver of multiple input multiple output (MIMO) radar system,a novel method is proposed for joint estimation of direction of departure (DOD),direction of arrival (DOA) and polarization parameters for bistatic MIMO radars.A signal model of polarimetric MIMO radar is developed,and the multi-parameter estimation algorithm for target localization is described by exploiting polarization array processing and the invariance property in both transmitter array and receiver array.By making use of polarization diversity techniques,the proposed method has advantages over traditional localization algorithms for bistatic MIMO radar.Simulations show that the performance of DOD and DOA estimation is greatly enhanced when different states of polarization of echoes is fully utilized.Especially,when two targets are closely spaced and cannot be well separated in spatial domain,the estimation resolution of traditional algorithms will be greatly degraded.While the proposed algorithm can work well and achieve high-resolution identification and accurate localization of multiple targets.
