大误差条件下单频干扰引起的伪码跟踪误差研究  

Effects of Continuous Wave Interference on Pseudorandom Code Tracking Error under Large Error Conditions

作　　者：瞿智[1] 杨俊[1] 杨建伟[1] 

机构地区：[1]国防科学技术大学机电工程与自动化学院,长沙410073

出　　处：《电子与信息学报》2016年第1期222-228,共7页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(61201031)~~

摘　　要：单频干扰能够引起较大的伪码跟踪误差,基于小误差条件的跟踪误差分析会失效。在大误差条件下,由于码环鉴相器不再工作在线性区域,利用鉴相器输出的二阶泰勒展开式代替一阶线性化近似,该文给出了单频干扰下伪码跟踪误差的解析表达式。通过数值分析和仿真实验分析验证了在单频干扰下伪码跟踪误差随干扰起始相位、干扰频率和干信比的变化特性。结果表明:当干扰引起的伪码跟踪误差较大时,基于鉴相器线性化的理论预测的准确性显著下降,而基于鉴相器二阶泰勒近似的理论分析能够准确预测大误差条件下的伪码跟踪误差,在跟踪误差不超过0.34 chip时,理论分析误差不超过20%。Continuous Wave Interference（CWI） can induce large code tracking error, and the tracking error analysis based on small error conditions becomes invalid. Under large error conditions, since code loop discriminator is no longer working in the linear region, the second-order Taylor series expansion of discriminator output is introduced instead of linear approximation, and analytical expressions of the tracking error in the presence of CWI are derived. Numerical analysis and simulation results are presented to evaluate the code tracking error with different initial phases,interference frequencies and interference-to-signal power ratio（ISR）. The experimental results show that, when the code tracking error induced by CWI is large, the prediction accuracy of theoretical analysis based on linearized discriminator decreases noticeable, while the new theoretical expressions based on second-order Taylor series expansion provide accurate predictions of code tracking errors under large error conditions. If the code tracking error is smaller than 0.34 chip, the theoretical prediction error is no more than 20%.

关 键 词：单频干扰 伪码跟踪误差 鉴相器 大误差条件 二阶泰勒展开 

分 类 号：TN98[电子电信—信息与通信工程]