锁相环中鉴相器的设计与仿真

Design and simulation of phase detector in PLL

根据软件无线电技术的特点和锁相环的基本原理,对常用的3种鉴相方法原理进行了分析与总结。将3种鉴相法分别应用到Costas环中,通过MATLAB在不同信噪比下对锁相环进行仿真,并从锁相精度和速度2个方面对锁相环的性能进行比较。仿真结果表明在相同的信噪比下,采用了不同鉴相法的锁相环表现不尽相同,这说明在一定条件下锁相环中鉴相器可以实现最优。最后针对比较结果总结出3种鉴相法的一般使用准则,可以节省设计时间,提高开发效率。

According to the characteristics of software radio technology and the basic principles of PLL,the three commonly used methods of phase detect are analyzed and summarized.The three kinds of methods are applied to the phase Costas loop,then we use MATLAB to simulate the PLL in conditions of different SNR,compare the performances of the PLL from both accuracy and speed.Simulation results show that even under the same SNR,performances of PLL are different if we use different phase detect methods,this suggests that under certain conditions,phase detector in PLL can achieve the best.Finally,according to the comparisons we summarize guidelines in general for the three kinds of phase detect methods,it can save design time and improve efficiency.