摘要
针对二进制偏移载波调制及其衍生信号自相关函数的多峰特性带来的跟踪模糊问题,提出一种基于信号相关函数特点的子函数组合相关的无模糊跟踪算法。首先,通过构建的形状码向量得到二进制偏移载波调制基准及衍生调制信号的通用互相关函数表达式,将接收信号的伪码作为本地参考信号,设计特殊的本地码波形与相应的接收信号进行相关运算得到信号相关子函数,然后利用重构规则重新组合子函数,得到边峰完全消除,保留单峰的新的相关函数。改进跟踪算法的码跟踪环路结构,相比传统的码跟踪环路结构,减少了滤波电路,结构有了简化,硬件的实现复杂度也有所降低。仿真实验结果表明,相关函数副峰消除的同时保留了主峰的尖锐性。通过与传统跟踪算法对比可知,在相同载噪比的前提下,该算法的码跟踪精度更高,鉴相函数不存在除过零点外的其他误锁点,不会造成误锁现象。相比传统的跟踪模糊消除算法,该方法不仅能有效地适用于BOCs(m,n)一类的基准调制信号,对于复合类衍生信号CBOC(6,1,1/11)也能实现无模糊精准跟踪。
Aiming at the tracking ambiguity problem caused by the multi-peak characteristic of the Binary Offset Carrier and its derivative signals autocorrelation function,this paper proposes an unambiguous tracking algorithm based on the characteristics of the signal correlation function.First,the general expression for the cross-correlation function for the BOC reference and derivative modulation signal is obtained by the shape code vector constructed in this paper.The pseudo code of the received signal is used as a local reference signal,and a special local code waveform is designed to perform correlation operations with the corresponding received signal to obtain a signal correlation sub-function.Then,the sub-functions are recombined using the reconstruction rules proposed in this paper,and the edge peaks are completely eliminated and a new correlation function with a single peak is retained.The code tracking loop structure of the improved tracking algorithm,compared with the traditional code tracking loop structure,reduces the filter circuit,the structure is simplified,and the hardware implementation complexity is also reduced.Simulation results show that the secondary peak of the correlation function is eliminated while retaining the sharpness of the main peak.By comparing with the traditional tracking algorithm,it can be seen that the code tracking accuracy of this algorithm is higher under the premise of the same carrier-to-noise ratio.The phase discrimination function does not have any false lock points except the zero crossing point,and will not cause a false lock problem.Compared with the traditional tracking ambiguity elimination algorithm,this method can effectively apply BOCs(m,n)and CBOC(6,1,1/11)signals without ambiguity tracking.
作者
孙希延
宋少杰
纪元法
梁维彬
李有明
SUN Xiyan;SONG Shaojie;JI Yuanfa;LIANG Weibin;LI Youming(Guangxi Key Laboratory of Precision Navigation Technology and Application,Guilin University of Electronic Technology,Guilin 541004,China;National&Local Joint Engineering Research Center of Satellite Navigation and Location Service,Guilin 541004,China)
出处
《西安电子科技大学学报》
EI
CAS
CSCD
北大核心
2022年第2期58-66,共9页
Journal of Xidian University
基金
国家自然科学基金(61861008,62061010,62161007)
广西科技厅项目(桂科AA19182007,桂科AA19254029,桂科AA20302022,桂科AB21196041)
广西自然科学基金(2018GXNSFAA294054,2019GXNSFBA245072)
桂林电子科技大学研究生教育创新计划(2021YCXS029)。
关键词
二进制偏移载波
无模糊跟踪
形状码向量
子函数组合
binary offset carrier
unambiguous tracking
shape code vector
sub-function combination
