CAJ | 학술논문

在超宽带(UWB)定位系统中，非视距(NLOS)传播是降低通信与定位精度可靠性的主要原因。因此，区分NLOS环境对提高定位精度尤为重要。针对该问题，提出了一种新的基于信道统计特性———偏度(Skewness)的NLOS区分算法。该算法首先将偏度在IEEE 802.15.4a信道模型(特别是室内家居和办公环境)中建模为对数正态分布，然后对其概率密度函数( PDF)做似然比检验来区分视距( LOS)与NLOS环境。仿真结果表明：室内UWB定位系统中，偏度可以更好地区分信道状态，在室内办公环境中，正确区分NLOS环境的概率可达99.99%。在定位模块中融入所获得的区分NLOS的结果将有助于定位精度的进一步提升。
재초관대(UWB)정위계통중，비시거(NLOS)전파시강저통신여정위정도가고성적주요원인。인차，구분NLOS배경대제고정위정도우위중요。침대해문제，제출료일충신적기우신도통계특성———편도(Skewness)적NLOS구분산법。해산법수선장편도재IEEE 802.15.4a신도모형(특별시실내가거화판공배경)중건모위대수정태분포，연후대기개솔밀도함수( PDF)주사연비검험래구분시거( LOS)여NLOS배경。방진결과표명：실내UWB정위계통중，편도가이경호지구분신도상태，재실내판공배경중，정학구분NLOS배경적개솔가체99.99%。재정위모괴중융입소획득적구분NLOS적결과장유조우정위정도적진일보제승。
Non-line-of-sight( NLOS) propagation can severely degrade the reliability of communication and localization accuracy in indoor ultra-wide-band( UWB) positioning systems. It was important to dis-tinguish NLOS for positioning precision. For this problem,a novel NLOS identification technique based on skewness is proposed,which is one of the channel statistics. The IEEE 802. 15. 4a channel models are employed for simulation. Skewness can be well modelled as a log-normal distribution especially in the indoor and office environments. Subsequently, a likelihood ratio test for Probability Density Function ( PDF) is used to identify LOS/NLOS. The simulation results show that skewness can better distinguish the channel state with up to 99 . 99 percent accuracy on the quiz responses in the indoor office environ-ments. Localization accuracy is expected to be improved by incorporating the NLOS identification results into the positioning module.