基于SIC的伪卫星系统抗远近效应捕获算法研究  

SIC-based anti near-far effect acquisition method for pseudolites systems

作　　者：刘旭 姚铮[1,2] 吕红丽 陆明泉 LIU Xu;YAO Zheng;LYU Hongli;LU Mingquan(Department of Electronic Engineering,Tsinghua University,Beijing 100084,China;Beijing National Research Center for Information Science and Technology,Beijing 100084,China;Shaanxi Key Laboratory of Integrated and Intelligent Navigation,Xi'an 710068,China;The 20th Research Institute of China Electronics Technology Corporation,Xi'an 710068,China)

机构地区：[1]清华大学电子工程系,北京100084 [2]北京信息科学与技术国家研究中心,北京100084 [3]陕西省组合与智能导航重点实验室,陕西西安710068 [4]中国电子科技集团公司第二十研究所,陕西西安710068

出　　处：《全球定位系统》2020年第1期12-18,共7页Gnss World of China

基　　金：国家自然科学基金(61771272);装备预研基金重点项目(6140518010101)。

摘　　要：地基伪卫星系统中由于远近效应的影响,近场伪卫星信号可能对远场伪卫星信号形成压制干扰,导致远场伪卫星信号无法被捕获.针对该系统中使用的跳时直接序列扩频(TH-DSSS)信号的捕获问题,引入串行干扰消除(SIC)技术,缓解伪卫星系统中的远近效应问题,通过本地重构强信号和干扰对消降低强信号对弱信号捕获的影响,并从理论和仿真两方面对其性能进行了分析.仿真结果表明,相比传统未采用干扰消除的捕获算法而言,基于SIC的信号捕获方法在不改变伪卫星基站结构和接收机框架的基础上,可有效降低远近效应的影响,提高弱信号捕获概率,扩大系统工作范围,从而为接收机在强远近效应场景下的捕获、跟踪和定位解算提供有效保障.In the Ground-based Pseudolites System,near-field pseudolite signals may interfere and suppress the far-field signals since the existence of near-far effect,causing failure acquisition of the far-field signals.A SIC-based acquisition method anti near-far effect is proposed in this paper,aiming at the acquisition of time-hopping direct sequence spread spectrum(TH-DSSS)signal implemented in this system.Interferences of strong signals to weak signals are reduced by reconstructing local replica of the strong signal and interference cancellation.The proposed method is analyzed in theory and simulation.Simulation results indicate that the SIC-based acquisition method has the ability to reduce the influence of near-far effect,increase the detection probability of weak signals and enlarge the operating range of system without changing the pseudolite base station structure and the framework of corresponding receiver,which provides an effective guarantee for the receiver to capture,track and position in scenarios with strong near-far effect.

关 键 词：地基伪卫星系统 远近效应 TH-DSSS信号 SIC 信号捕获 

分 类 号：P228.4[天文地球—大地测量学与测量工程]