In order to reduce the interference of the NLOS environment to the wireless location system,a time-delay estimation scheme based on genetic algorithm is proposed. This scheme utilizes the characteristics of heuristic stochastic search ability of genetic algorithm, and the delay of LOS-path under NLOS environment can be obtained. Firstly,it uses the time of arrival and the angle of arrival as the o-riginal information in genetic algorithm. Secondly,according to the original information,it constructs an adaptive fitness function. Finally, the solution of the objective function is calculated,and the delay of LOS-path is obtained. The simulation shows that compared with the traditional time-delay estimation based on generalized cross correlation,the proposed scheme can effectively reduce the ambient noise un-der NLOS environment. On the premise of the objective function being able to describe the environment,genetic algorithm has the ability of fast solving the dominant solution under the complex environment,and it can meet the requirements of positioning service response speed and positioning accuracy for various kinds of position-service-based applications.%为降低NLOS环境对无线定位系统的干扰,文中提出了一种基于遗传算法的定位服务时延估计方案.该方案利用遗传算法启发性随机搜索的能力,求出NLOS环境下基站与移动台间的直视径时延.以各路径的到达时延以及到达角作为遗传算法的初始化信息,构建具有自适应性的适应度函数,通对目标函数求解得到直视径时延.仿真结果表明,该方案与传统的基于广义互相关的时延估计方案相比,可以有效降低NLOS环境下的环境噪声.在目标函数基本能够描述环境的前提下,遗传算法具有快速求解复杂环境下优势解的能力,可以满足各类依赖定位服务的应用对定位服务响应速度以及定位精度的要求.
展开▼
