一阶动态条件下伪随机码信号相关函数研究

在直接序列扩频系统中,受收发两端的相对运动和时钟频率不稳定等因素的影响,接收伪码和本地伪码之间会存在一定的码率偏移.本文首次采用对常规伪码相关函积分的方法推导了一阶动态即恒定码率偏移条件下任意长积分时间伪随机码信号相关函数公式,对所得公式进行了仿真验证,在此基础上分析了一阶动态条件下伪随机码信号相关函数的特征,包括主瓣展宽、峰值移位和损耗等现象.本文结论为高动态接收机伪码同步技术提供了理论基础.

Correlation of PN Spread Spectrum Signal Under First-Order Dynamics

In direct sequence spread spectrum systems,due to dynamic factors such as the relative motion between the transmitter and the receiver and the instability of clock,there is code-frequency offset between the received and the local PN codes.In this paper,assuming first-order dynamic,namely,constant code-frequency offset,the formulas for the correlation function of PN code are derived for the first time by the method of integrating the normal PN code correlation function with an integration time interval of arbitrary length and then verified by simulation.Accordingly the characteristics of PN code correlation function under first-order dynamic are studied,including spread of main-lobe,shift and loss of peak.The conclusions drawn in this paper can guide the design of code synchronization in high dynamic receiver.