参数字典动态更新的SOMP离网格直接定位方法

Dynamic Grid Direct Position Determination Algorithm Based on SOMP

在网格直接定位方法的精度依赖于网格划分的精细程度,传统离网格方法缓解了对网格划分的依赖,但是仍然存在补偿精度低、算法复杂度过高的问题。针对这些问题,本文提出了一种参数字典动态更新的SOMP(Simultaneous Orthogonal Matching Pursuit)离网格直接定位方法。首先,利用子空间适应的方法对初始信号进行降噪处理,对二维空间进行粗网格的划分。其次,引入网格量化误差,不同于JSOMP(Joint Simultaneous Orthogonal Matching Pursuit)方法迭代后结算补偿值的方式,该方法在迭代的过程中使用泰勒补偿对每一次匹配相关度最高的网格点进行单源补偿,更新原有字典矩阵参数,从而得到较为理想的字典矩阵。仿真结果表明,本文所提算法能够有效克服网格失配的问题,得到精准的信源位置估计结果,相比于JSOMP、OG-SBI(Off-Grid Sparse Bayesian Inference)、MUSIC-Taylor(Multiple Signal Classification Based on Taylor Compensation)离网格方法,本文所提方法的运算速度更快、定位精度更高。

The accuracy of the direct positioning determination depends on the fineness of the grid division,and the traditional off-grid method alleviates the dependence on the grid division,but it still has the problems of low compensation accuracy and high algorithm complexity.In order to solve these problems,this paper proposes a dynamic grid direct position determination algorithm based on SOMP.Firstly,the initial signal was denoised by employing subspace adaptation method,and the two dimension space of interest was divided into scattered grids.Secondly,the grid quantization error was considered in this paper and the influence on direct position determination was analyzed.Lastly,the proposed method was introduced.The method was different from the traditional method of JSOMP which was also based on SOMP and settled the compensation value after all iterations.In the process of each iteration,the method employed Taylor compensation to improve the location of the grid point which had the highest correlation with the received signal.At the same time,the related parameter of the original dictionary matrix was replaced with the updated one,so as to obtain a more optimal dictionary matrix.The results of the computer simulation tests showed that the proposed algorithm could overcome the grid mismatch problem effectively and estimate position of radiation source accurately.Compared with JSOMP,OG-SBI and MUSIC-Taylor algorithms,the proposed method has higher speed of operation and lower deviation of position location.