存在基站误差的稳健时差定位算法  

Robust source location algorithm using TDOA in the presence of sensor position errors

作　　者：房嘉奇[1] 冯大政[1] 李进[1] 

机构地区：[1]西安电子科技大学雷达信号处理国家重点实验室,陕西西安710071

出　　处：《系统工程与电子技术》2015年第5期998-1003,共6页Systems Engineering and Electronics

基　　金：国家自然科学基金(61271293)资助课题

摘　　要：针对存在基站误差的目标无源定位问题,提出了一种基于修正牛顿算法的时差定位技术。众所周知,牛顿法对初值要求较高,较差初值会导致迭代发散,而且基站位置误差也会导致牛顿算法Hessian矩阵维数扩大和目标函数的缓慢下降,使运算量变大。该算法利用最大似然方法确定目标函数,运用牛顿法对目标位置进行迭代求解,对于计算过程中可能出现的病态Hessian矩阵,引入正则化理论修正病态的Hessian矩阵,使保证迭代收敛,同时简化算法降低Hessian矩阵的维数并且加速目标函数的下降趋势,使目标位置解脱离局部最小值,算法能够稳健高效的运行。实验结果表明:相对于传统牛顿法,此算法在初始值的选取上具有稳健性,对误差选取较大的初始值,仍能够保证算法的收敛性,同时加速了收敛速度,降低了计算量;相对于现有闭合式定位方法,此算法在噪声较大时具有较好的定位精度。For the source localization problem in the presence of sensor position errors, this paper presents a time-difference-of-arrival（TDOA）technique based on the modified Newton（MNT）algorithm. It is known that the NT algorithm suffers from the initialization problem. A bad initial may cause the iteration divergence. In ad- dition, inaccurate sensor position condition also causes the NT algorithm computationally intensive due to the high-dimension matrix and the slow downtrend of the objective function. The new algorithm uses the maximum like- lihood method to determine the objective function. For the problem of the ill-condition Hessian matrix caused by the bad initial, the algorithm introduces the regularization theory to modify the Hessian matrix, which ensures the iteration convergence. Meanwhile, the proposed algorithm reduces the degree of the high-dimension matrix and increases the downtrend of the objective function, and makes the solution escape from the local minimum value via a simplified iterative criterion. Experiment results show that compared with the classical Newton method, this new algo- rithm is robust to the initial value, and is still able to ensure its convergence even with an inaccurate initial value of large errors, it also speeds up the convergent rate and cuts the computation. Compared with some other closed-form source location methods, the new algorithm has better accuracy in large noise levels.

关 键 词：时差定位 基站误差 HESSIAN矩阵 正则化算法 克拉美罗界 

分 类 号：TN97[电子电信—信号与信息处理]