一种可克服非相干数据影响的直扩信号捕获算法

摘要

This paper proposes a kind of acquisition algorithm for Direct Sequence Spread Spectrum (DS-SS) signal, which can overcome the adverse impact of the non-coherent data modulation effectively. In the algorithm,the received signal is multiplied by its delay conjugate result to eliminate the impact of the data transition.Then the Fast Fourier Transform (FFT) is used to calculate the circular correlation to estimate the PN code phase. After that, we use the estimate result of the PN code phase to despread the received signal and get the estimate of the Doppler frequency, which is achieved by frequency spectrum analysis with FFT. Theoretical analysis and simulation results show that, compared with the traditional algorithms, the proposed algorithm is not sensitive with the moment the data transition occurs and it saves the acquisition time significantly.The algorithm proposed in this paper can be applied to capture high-speed non-coherent data modulated signals.%本文提出了一种可克服非相干数据调制影响的直扩信号捕获算法.该算法首先通过延迟共轭相乘克服数据位跳变影响,并通过快速傅立叶变换(FFT)计算圆周相关获得接收信号伪码相位的快速预测；然后使用捕获到的伪码相位对接收信号进行解扩,并利用FFT频谱分析完成接收信号载波多普勒频率的捕获.理论分析及仿真均表明,与已有的算法相比,本文提出的算法对数据位跳变时刻不敏感,捕获时间短,适用于非相干数据位调制直扩信号的快速捕获.