一种应用于地基导航系统的发射分集抗多径技术

摘要

Compared with the satellite navigation, the ground-based navigation has more complicated multipath environment. The receiver achieves anti-multipath effect by receiving a plurality of transmitted ground-based navigation signals, and then selecting the one that is affected least by multipath for the range and position. It is a key part of transmit diversity to choose a reasonable method to judge the multipath severity degree. As the Non-Symmetry Degree of correlation peak can not embody the multipath error effectively when the multipath signal and the direct signal are inverted superposition, a method named NSU judgement is proposed based on the Non-Symmetry Degree of the correlation peak and SNR. The anti-multipath effect can be achieved by selecting and receiving the right signal from several ground-based navigation signals. Simulation results verify the effectiveness of this approach.%与卫星导航相比,地基导航的多径环境更加复杂.接收机接收多路发射分集的地基导航信号,选择其中受多径影响最弱的一路导航信号参与测距定位,从而消弱多径效应的影响.选择一种合理的算法对多径严重程度进行判决便成为发射分集抗多径技术的关键.针对相关峰不对称度在多径信号与直达信号反相叠加时无法有效反映多径误差的问题,提出一种基于不对称度和信噪比的NSU判决法,对发射的多路地基导航信号进行选择接收,达到抗多径目的.仿真结果验证了这种方法的有效性.