伪码测距接收机中MET技术误差建模与分析

Modeling and Analysis of Multipath Eliminating Technique of PN Code Ranging Receiver

为了分析多径干扰对多径消除技术(MET)的影响,建立了MET的跟踪误差模型.MET的鉴相函数既可表示为窄相关技术鉴相函数的复合形式,又可表示为直接信号的鉴相函数与多径信号鉴相函数之和.同时多径信号的鉴相函数本质上是直接信号鉴相函数的平移和尺度变换,利用鉴相函数的这一特性对MET的跟踪误差进行分析和建模.通过仿真比较了MET、窄相关技术以及strobe相关器技术的多径误差抑制性能.结果表明MET可以完全消除中等长度时间延迟的多径信号造成的误差,并且可以通过调整相关间距来减小MET跟踪误差.

To analyze the effect of multipath disturbance on multipath eliminating technique（MET）,the error model of MET is established.The discriminator function of MET not only can be expressed as the composition of discriminator function in narrow correlative technique but also can be formulated by the sum of discriminator function with respect to the direct signal and that with respect to multipath.Meanwhile,since the discriminator function with respect to multipath is the shifting and scaling of that with respect to direct signal in natural,the tracking error of MET can be analyzed and modeled utilizing this characteristic of discriminator function.The performance of MET,narrow correlator technique and strobe correlator technique is compared via simulation.The results indicate that the error caused by medium multipath can be removed by MET,and the tracking error of MET can be reduced by small correlator spacing.