基于循环谱的直扩信号到达时差估计

以循环谱理论为基础,分析了直扩信号在平稳噪声及窄带干扰情况下的循环统计特性,研究了直扩信号的到达时差估计模型和提取方法。在单一循环频率的基础上,对算法进行改进,提出了全相干循环估计器的到达时差算法。通过计算机仿真,验证了改进算法不仅对信号具有选择能力,而且较单循环估计器和传统互相关方法具有更强的抑制噪声能力。最后通过仿真得到了估计性能曲线,验证了理论的正确性。

Estimation for Step-out Time Difference of DSSS Signal Based on Cyclic Spectrum

The cyclic statistics characteristic of DSSS signal in stationary noise and narrowband interference is analyzed based on the theory of cyclic spectrum.The model of the step-out time difference estimation and extraction method are investigated.On the basis of single cyclic frequency,the algorithm is improved and the time difference estimation is proposed with full coherence cyclic estimator.The computer simulation proves that the improved algorithm not only has the selectivity for signals,but also has stronger ability to suppress the niose than those of the single cyclic estimator and the traditional methods.The performance curves obtained by simulation are offered to verify the correctness of the theory.