扩频码跟踪及同步失锁的研究与实现

Research and Implementation of Spread-Spectrum Code Tracking and Synchronization Loss

针对扩频通信系统中的PN码同步问题,在分析扩频码跟踪方法的基础上,讨论了同步失锁问题,给出非相干延迟锁定环的计算公式和降低同步失锁误判的方法,并对其进行Matlab仿真及FPGA硬件调试。结果表明:该同步系统能够很好地跟踪接收端PN码的相位变化,失锁电路能够有效工作,并准确判断出同步失锁状况。

To solve the problem of PN code synchronization,synchronization loss was discussed based on the analysis of spreading code tracking methods in spread-spectrum communication system.Calculation formula for noninterference delay locked loop and method to reduce misjudgement for synchronization loss were presented.Simulation in Matlab and FPGA-based hardware debugging were conducted.Results showed that the synchronization system performed well in tracking phase change of receiver PN code,and the loss circuit,which did an effective job,could determine status of synchronization loss accurately.