关键词: B1C信号捕获, 多峰性, 伪相关函数, 联合捕获, 降采样

Abstract: In order to solve the problem of ambiguity in baseband signal processing due to the existence of multi-peaks in the autocorrelation function of B1C signal, a unambiguous acquisition algorithm based on the reconstruction of pseudo-correlation function(PCF)is proposed. The algorithm reconstructs the correlation function to eliminate the secondary peaks and increase the peak of the main peaks, and improves the acquisition sensitivity by combining the data and the pilot component of the B1C signal. At the same time, the algorithm uses downsampling strategy and FFT parallel capture strategy to reduce the computational complexity. Simulation analysis results show that: the improved algorithm can achieve B1C signal capture and completely eliminate the secondary peaks while improving the primary peaks, and- DOI:10.3969/j.issn.1000-1565.2023.03.013基于PCF重构的北斗B1C信号无模糊捕获算法王鹏^1,2,张展豪^1,3,金志威^1,2,徐庆^1,2(1.民航航空器适航审定技术重点实验室,天津 300300;2.中国民航大学 安全科学与工程学院,天津 300300;3.中国民航大学 中欧航空工程师学院,天津 300300)摘 要:针对B1C信号自相关函数存在多峰性会导致基带信号处理过程中存在模糊性问题,提出一种基于伪相关函数(pseudo-correlation function,PCF)重构的无模糊捕获算法,对互相关函数进行重构消除副峰并提高主峰峰值,将B1C信号的数据和导频分量进行联合捕获提高捕获灵敏度,同时引入降采样和FFT并行捕获策略降低计算复杂度.仿真结果分析表明:改进算法可以实现B1C信号捕获,改进算法在提高主峰的同时,完全消除了副峰,实现了B1C信号捕获的无模糊性.其捕获时间相比其他算法缩短近1/2,在信噪比高于13 dB时,主峰比例均值趋于稳定,最高相比Filtered法提高67.74%,在捕获概率为0.9时联合捕获载噪比低于导频单通道捕获1.8 dB·Hz,并在较低载噪比情况下较其他算法具有更好的适应能力.关键词:B1C信号捕获;多峰性;伪相关函数;联合捕获;降采样中图分类号:TM967.1 文献标志码:A 文章编号:1000-1565(2023)03-0320-10Unambiguous acquisition algorithm of Beidou B1C signal based on PCF reconstructionWANG Peng^1,2, ZHANG Zhanhao^1,3, JIN Zhiwei^1,2, XU Qing^1,2(1. Key Laboratory of Civil Aircraft Airworthiness Technology, CAAC,Tianjin 300300, China; 2. College of Safety Science and Engineering,Civil Aviation University of China,Tianjin 300300,China; 3. Sino-European Institute of Aviation Engineering, Civil Aviation University of China, Tianjin 300300, China)Abstract: In order to solve the problem of ambiguity in baseband signal processing due to the existence of multi-peaks in the autocorrelation function of B1C signal, a unambiguous acquisition algorithm based on the reconstruction of pseudo-correlation function(PCF)is proposed. The algorithm reconstructs the correlation function to eliminate the secondary peaks and increase the peak of the main peaks, and improves the acquisition sensitivity by combining the data and the pilot component of the B1C signal. At the same time, the algorithm uses downsampling strategy and FFT parallel capture strategy to reduce the computational complexity. Simulation analysis results show that: the improved algorithm can achieve B1C signal capture and completely eliminate the secondary peaks while improving the primary peaks, and- 收稿日期:2022-10-19 基金项目:国家重点研发计划项目(2021YFB1600600);中央高校基本科研业务费资助项目(XJ2021003601) 第一作者:王鹏(1982—),男,天津人,中国民航大学研究员,博士,主要从事系统安全性设计与评估、卫星导航信号处理、机载电子硬件适航技术方向研究.E-mail:pwang_cauc@163.com 通信作者:金志威(1987—),男,天津人,中国民航大学助理实验师,主要从事机载电子硬件适航审定、卫星导航信号处理等方向研究.E-mail:zwjin_87@163.com第3期王鹏等:基于PCF重构的北斗B1C信号无模糊捕获算法achieve the signal acquisition without ambiguity. Its acquisition time is shortened by nearly 1/2 compared with other algorithms, and the mean value of the main peak ratio tends to stabilize at signal-to-noise ratios higher than 13 dB, with a maximum improvement of 67.74% compared with the Filtered method. The 0.9 detection probability of the combined acquisition strategy is better than that of the pilot single-channel acquisition by 1.8 dB·Hz, and it has better adaptability than other algorithms at lower carrier-to-noise ratios.

Key words: B1C signal acquisition, multi-peakedness, pseudo-correlation function, combined acquisition, downsampling