基于最大似然准则的CHAN改进算法

摘要

Chan algorithm is a classical and effective solving algorithm for TDOA (time difference of arrival)localisation with closed-formsolution,however,in practical application there exists some difficulties and deficiencies.In this paper we first illustrate the solutions set ofChan algorithm in 2-D plane,and propose a maximum likelihood criterion-based location ambiguity removal method to obtain the only finalsolution.Secondly,aiming at the phenomenon that the location accuracy of Chan algorithm decreases obviously at large TDOA measuringerror,we propose a method to modify the position estimation obtained by Chan algorithm,which is based on approximate maximum likelihood,to improve its location performance.At last,the results of simulations show that the improvement measures proposed on Chan algorithm arefeasible and effective.%Chan算法是一种经典的具有闭式解的高效时差定位解算算法，但在实际应用中却存在一些困难和不足。首先对Chan算法在二维平面下的解集作了说明，并提出一种基于最大似然准则的定位模糊消除方法以得到唯一最终解，其次，针对Chan算法在较大时差测量误差下定位精度下降明显的现象，提出一种基于近似最大似然的方法对Chan算法定位估计进行修正，以改善其定位性能。仿真结果表明，对Chan算法提出的改进措施是有效可行的。