【摘要】 移动通信系统中,针对移动台的定位精度问题,提出基于A-GPS的混合定位方法。当GPS无法独立完成定位需求时,则切换至基于移动台的定位方法完成定位服务。在基于移动台的定位算法上,采用到达时间差(TDOA)的方法,并通过最小二乘法降低由非视距传播带来的误差影响,提高TDOA的定位精度。经过计算机的仿真试验,证实此算法在一定噪声环境中能够达到克拉美罗下限,并且优于其它同类算法,取得了较好的定位效果:适用范围广,定位速度快、精度高,完全可以满足定位服务的要求。更多还原

【Abstract】 In mobile communication system,a new method of mobile station location was presented to improve the location precision,which was based on assist Global Position System,and combined with TDOA method.In this method,when GPS cannot locate MS independently,TDOA algorithm will be used to locate the position.Least Squares algorithm was used to mitigate the influence,which was brought by NLOS,and improved the precision of TDOA.The performance of the proposed algorithm is evaluated analytically and via computer simulations.Simulation results show that the LS estimator achieves the Cramér-Rao lower bound under sufficiently high signal to noise conditions,and better than other similar algorithms.This method is faster,more accurate,and fit for more situations.It meets the requirement of position services completely.更多还原