一种CDMA蜂窝定位中减小NLOS误差的算法

随着下一代移动通信研究的热潮,移动定位技术的研究也方兴未艾。在移动定位方程的解算中,测量噪声和NLOS误差是主要误差源,尤其是NLOS已经成为影响定位精度的主要因素。本文研究了CDMA系统中的NLOS误差减小问题,基于残余函数概念提出了ARWA算法,在NLOS路径不能有效识别的条件下,有效地减小了NLOS误差;仿真结果显示这种算法的定位精度明显强于一般LS估计。

A NLOS error mitigation algorithm for location in CDMA cellular networks

The location estimation of mobile phones is of great interest along to next generation mobile communications. The two sources of range measurement errors in location techniques are measuring error and Non-Line-of-Sight (NLOS) error. NLOS errors, deriving from blocking of line of sight, have become a killer issue in mobile location. In this paper, we investigate the NLOS error mitigation algorithm for Time of Arrival based mobile phone in CDMA cellular systems. This algorithm, referred to as Adaptive Residual Weighting Algorithm (ARWA), assumes that the number of range measurements is greater than the minimum number required. Although NLOS cannot be availably identified from LOS, the location estimation error can be efficiently mitigated. The ARWA is compared with general LS estimator, and tested the performance under various scenarios and NLOS error models, which includes deterministic and random NLOS error models. In both cases, ARWA has shown the effectiveness of location accuracy improving.