基于TDDM调制信号载波跟踪环路仿真

The Simulation of Carrier-track Loop on the Basis of the TDDM Signals

在对TDDM调制信号分析的基础上,对TDDM调制信号的载波跟踪方法进行了深入研究.对常用的科斯塔斯环和平方环进行了分析,并针对TDDM调制信号的特点,对原有的锁相环进行改进,把TDDM调制信号分成两路进入锁相环,选择无数据载波进行跟踪.在Matlab环境下对三种跟踪方法进行了仿真.仿真结果表明,在对TDDM调制信号进行跟踪时,改进的锁相环比其他两种跟踪环具有更精确的跟踪效果.

On the basis of the analysis of TDDM modulation signal, the tracking methods of TDDM modulation signal are carried out in-depth research. Costas loop ring and squaring loop ,which are used commonly, are analyzed. And the characteristics of TDDM modulation signal are considered, so the original PLL is improved. The TDDM modulation signal is divided into two groups to enter the PLL, Then the non - data carrier is chosen to carry on tracking. Then the three tracking methods are simulated in Matlab. The simulation results show that on the tracking process of TDDM modulation signal,the tracking effect of improved PLL is more accurate than the other two tracking loops.