摘要
针对非相干数据调制破坏周期性伪码的相关特性、高动态引起严重的多普勒效应导致信号捕获频率估计精度低、码载搜索时间长的问题,提出了一种码载分离处理的快速高精度捕获算法。相位搜索支路采用平均分组压缩和相位延时差分相结合进行扩频伪码相位的高精度捕获,频率测量支路采用捕获到的本地伪码对采样数据进行相关解扩,再采用非线性变换、补零快速傅里叶变换(Fast Fourier Transform,FFT)和抛物线拟合相结合实现载波多普勒频移的高精度估计。实验与分析表明,该算法在载波多普勒频移±75 kHz条件下信号捕获时间仅约20 ms,频率估计精度优于10 Hz。
The worse periodic pseudo-code correlation of direct sequence spread spectrum(DSSS)signal destroyed by non-coherent data modulation leads to low frequency estimation accuracy,and the serious Doppler effect caused by high dynamic results in more code phase/carrier frequency search time.A fast and high-accuracy acquisition algorithm based on pseudo-code and Doppler frequency separation is proposed to overcome above problems.Firstly,the combined method with average grouping compression and phase delayed difference is applied to accurately acquire spread spectrum pseudo-code phase in phase search branch.Then,the local pseudo-code from phase search branch is used to decode the sampled data,and the combined method with the nonlinear transform,the zero-filled fast Fourier transform(FFT)and the parabola fitting is employed to accurately estimate carrier Doppler frequency shift in Frequency measurement branch.The experiments and analysis verify that the proposed algorithm can achieve the acquisition time only about 20 ms and the frequency estimation accuracy is up to 10 Hz with±75 kHz Doppler frequency shift.
作者
金磊
吴卓亮
曾富华
王媛
蒋友邦
JIN Lei;WU Zhuoliang;ZENG Fuhua;WANG Yuan;JIANG Youbang(Southwest China Institute of Electronic Technology,Chengdu 610036,China;Unit 93209 of PLA,Beijing 100085,China)
出处
《电讯技术》
北大核心
2026年第2期281-288,共8页
Telecommunication Engineering
关键词
直扩信号
高精度捕获
非相干数据调制
高动态
多普勒频移
DSSS signal
high-accuracy acquisition
non-coherent data modulation
high dynamic
Doppler frequency shift
