中文摘要：

针对微波着陆系统（MLS）测距与测角功能分别独立工作带来的高复杂度、低机动性的问题,提出了基于伪随机码的自适应测距方法。该方法首先利用测距信号过采样后的欠采样值通过多周期伪码的并行频率搜索完成伪码捕获、多普勒频移精确估计和数据字提取,实现自适应测距;然后通过确定过采样值翻转点实现伪码跟踪,减小测距误差。仿真分析表明伪随机码可以被快速、准确地捕获跟踪,从而验证了方法的可行性。

英文摘要：

To solve the problems of high complexity and low mobility brought by functions of ranging and direction finding of microwave landing system（MLS）working independently,a self-adaptive ranging method based on PN code was proposed.At first,the ranging signal of under-sampling from over-sampling was used to realize functions of PN code acquisition,Doppler frequency shifted estimation and dates acquisition by parallel frequency searching of multiple cycles PN code,which achieved self-adaptive ranging.And then the system achieved PN code tracking by making turning point of oversampling sure,which could reduce ranging error.Simulations indicated that the PN code could be captured and tracked quickly and accurately,which verified the method feasibility.