一种二级分段PMF-FFT卫星信号捕获算法
A two-stage segmented PMF-FFT satellite signal acquisition algorithm
黄海生 1张弛 1李鑫 1丁福恒2
作者信息
- 1. 西安邮电大学 电子工程学院,陕西 西安 710121
- 2. 联通(陕西)产业互联网有限公司,陕西 西安 710086
- 折叠
摘要
针对在小点数快速傅里叶变换(Fast Fourier Transform,FFT)中,经典分段匹配滤波(Partial Matched Filte-ring,PMF)与 FFT 相结合的 PMF-FFT 卫星信号捕获算法存在增益损失,导致捕获灵敏度低、频率覆盖范围小和搜索速度慢的问题,提出了一种改进的二级分段PMF-FFT卫星信号捕获算法.截取部分 FFT 频率分量,缩短算法有效频率覆盖范围,以改善分段求和带来的包络增益衰减;采用在 FFT 频率分量中间位置追加搜索的方法,以改善FFT带来的扇贝损失;使用从粗略搜索到高精度搜索的策略,以减少搜索次数,提高搜索速度.仿真结果表明,相比经典PMF-FFT算法,在 FFT点数不大于 64 点的情况下,改进算法能有效提高搜索增益和搜索速度,在 8 点 FFT、125 Hz频率精度条件下,平均增益提升了 22.19%,搜索次数减少了 7.69%.
Abstract
In the case of fast Fourier transform(FFT)with a small number of points,the traditional partial matched filtering(PMF)combined with FFT satellite signal acquisition algorithm,PMF-FFT,has significant gain loss leading to low capture sensitivity and small frequency coverage range that results in slow search speed.An improved two-stage segmented PMF-FFT satellite signal ac-quisition algorithm is proposed to solve this problem.By truncating some FFT frequency compo-nents and shortening the effective frequency coverage range of the algorithm,the envelope gain at-tenuation caused by the segment summation is improved;by appending searches at the middle posi-tion of the FFT frequency components,the scallop loss caused by the FFT is improved;by adopting a strategy from rough search to high-precision search,the number of searches is reduced and the search speed is increased.Simulation results show that compared with the traditional PMF-FFT al-gorithm,the improved algorithm can effectively improve the search gain and search speed when the number of FFT points is not more than 64.Under the condition of 8-point FFT and 125 Hz frequen-cy accuracy,the average gain is increased by 22.19%,and the number of searches is reduced by 7.69%.
关键词
全球导航卫星系统/捕获算法/分段匹配滤波/快速傅里叶变换/包络衰减/扇贝损失Key words
global navigation satellite system/capture algorithm/partial matched filtering/fast Fou-rier transform/envelope attenuation/scallop loss引用本文复制引用
基金项目
陕西省重点研发计划(2022GY-011)
出版年
2024
NETL
NSTL
维普
万方数据