卫星时分多址信号高精度快速时频差联合估计方法High-accuracy and Fast TDOA/FDOA Estimation Method for Satellite TDMA Signals
陈潇扬,邱乐德,李帅,李明,辛宁
摘要(Abstract)：
针对传统时频差估计方法对时分多址(TDMA)信号进行参数估计时会出现不同用户相互影响、估计精度差,以及计算复杂度高不利于系统实时信号处理等问题,文章提出一种高精度快速时频差联合估计方法。首先,基于循环平稳特征对主站接收数据进行信号检测;然后,基于小波阈值去噪和短时电平和进行TDMA信号时隙分离;在此基础上,基于不同调制信号特征参数设计多级分类器,对每个分离的信号时隙进行调制样式判别,进而分选不同用户对应的信号时隙;接着,利用主站分选的各个用户信号分别与辅站信号进行时频差粗值估计;根据粗时频差估计值减小细化时差搜索范围,以获取精细时频差估计值;最后,利用二阶曲面拟合方法进一步提升参数估计精度。仿真结果表明:文章所提方法能够有效实现TDMA信号高精度快速时频差联合估计,可为后续卫星频谱感知体系的建设提供理论支撑。
关键词(KeyWords)： 卫星时分多址信号;互模糊函数;时频差估计
基金项目(Foundation): 国家重点研发计划项目(2020YFB1807900)
作者(Author): 陈潇扬,邱乐德,李帅,李明,辛宁
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