面向地面CDMA定位系统的微频分互相关减轻方法  

Mitigation of cross correlation based on micro-frequency division for terrestrial CDMA positioning systems

作　　者：余彦培[1,2] 邓中亮[1,2] 袁协[1,2] 万能[1,2] 

机构地区：[1]北京邮电大学电子工程学院,北京100876 [2]信息光子学与光通信国家重点实验室,北京100876

出　　处：《高技术通讯》2013年第11期1124-1130,共7页Chinese High Technology Letters

基　　金：863计划(2012AA120801;2012AA120802)资助项目

摘　　要：为解决地面码分多址（CDMA）定位系统互相关干扰现象严重的问题，从信号体制的角度进行互相关干扰理论分析，分析了CDMA信号频率间隔、扩频码周期及积分时间等三要素与信号互相关干扰分量的关系，提出了基于微频分技术的互相关干扰减轻方法：对不同信号节点发射的信号进行微小频移（即微频分），设计扩频码周期并调整积分时间实现互相关干扰消除。该方法与现有基带互相关干扰抑制方法并不冲突，仿真结果表明，它可面向室内等应用场景，在不增加基带处理复杂度的情况下实现强弱信号差达34～40dB的弱信号检测，有效提高系统的互相关干扰抑制能力。For mitigation of the serious cross correlation interference in a terrestrial code division multiple access （CDMA） positioning system, the theory of crosscorrelationinterference, time on cross correlation, were analyzed, and the im pacts of CDMA signal frequency interval, spreading code period and integration from the perspective of signal struc ture. Based on that, a microfrequencydivision based solution to mitigate cross correlation interference was pro posed. It works by 3 steps of settings ： microfrequencyoffsets in between signals, setting period of spreading code and time of integration. This method does not conflict with the existing methods for baseband cross correlation inter ference mitigation. The simulation results show that the new method can be applied to scenarios such as indoor, and it can detect the weak signals whose strength are 3440dB lower than the strong ones without increasing the base band complexity, while mitigating crosscorrelationinterference significantly.

关 键 词：互相关 频分 码分多址(CDMA) 扩频码 弱信号 

分 类 号：TN929.5[电子电信—通信与信息系统]