提高北斗BOC信号捕获精度的伪码相位估计法  

Pseudo code phase estimation method for improving BOC signal acquisition accuracy of BeiDou

作　　者：朱建良[1] 王兴全[2] 薄煜明[1] 吴盘龙[1] 赵婉璐[1] 

机构地区：[1]南京理工大学自动化学院,南京210094 [2]天津航海仪器研究所,天津300131

出　　处：《中国惯性技术学报》2014年第1期79-82,88,共5页Journal of Chinese Inertial Technology

基　　金：国家自然科学基金(61104196)

摘　　要：针对北斗二号将要采用的BOC信号粗捕获精度不足的问题,提出一种改进的伪码相位估计法。首先根据北斗将要采用的MBOC(6,1,1/11)调制方式,利用ASPeCT方法大幅削弱BOC信号旁瓣的影响;其次,利用频域FFT码相位循环相关法进行MBOC信号的粗捕获;最后,采用最小二乘拟合和三次样条插值的伪码相位估计法提高捕获精度。仿真结果表明,使用ASPeCT方法削弱旁瓣的影响后,最小二乘拟合和三次样条插值都能够使捕获误差均值减少到粗捕获误差的约1/10,三次样条插值误差均值最小,最小二乘拟合稳定性较好,具有更小的方差,适合干扰较大的场合。Due to the inaccuracy of BOC signal acquisition method to be used by BeiDou, the idea of using Pseudo code phase estimation is proposed to improve the acquisition accuracy. First, the paper greatly eliminates the effect of sidelobe by using the ASPECT method according to the MBOC（6,1,1/11） modulation method to be used by BeiDou. Second, the paper acquires MBOC signal by using the frequency domain FFT code phase circulation correlation algorithm. And last, the paper uses the least square fitting and cubic spline interpolation algorithm to improve acquisition accuracy. Our simulation results show that after eliminating the sidelobe effect using ASPECT, the least square fitting and the cubic spline interpolation algorithm can both reduce the mean error to 1/10 of its original value. Compared with the cubic spline interpolation algorithm, the least square fitting has better stability and smaller variance, which is fit for some scenarios with large interference, while the cubic spline interpolation algorithm has the smallest mean error.

关 键 词：北斗二号 捕获 BOC 三次样条插值 最小二乘拟合 

分 类 号：U666.1[交通运输工程—船舶及航道工程]