一种QPSK载波恢复环防错锁优化方法

针对QPSK信号的相干解调器中存在载波捕获错锁的实际工程问题,研究了目前常用的防错锁方法;在此基础上,提出了一种改进的中频信号数字频域处理方法,通过设计合适的等效滤波器,并对数字锁相环载波频率增加限制条件,有效地降低了载波捕获时发生错锁的概率。仿真试验结果和实际工程系统均验证了该防错锁优化方法的可行性。

An Anti-false-lock Optimization Method on Carrier Recovery Loop of QPSK Demodulation

The most commonly used methods of false-lock prevention in QPSK carrier acquisition are studied for QPSK demodulator in practical engineering problems. Based on the research, an optimized method of IF signals frequency domain processing is raised. By adding restrictive condition on the frequency of digital phase locked loop and the design of appropriate equivalent filters, the probability of false-lock in carrier acquisition is reduced obviously. The feasibility of the new method is verified by simulation results and application in practical engineering systems.