基于PAM分解的高阶部分响应CPM信号盲定时同步算法

针对高阶部分响应连续相位调制(CPM)信号盲定时同步中存在定时精度较低以及容易出现假锁等问题,该文从脉冲幅度调制(PAM)分解的角度出发,设计了一种新的适用于高阶部分响应CPM信号的定时同步器结构,并在此基础上结合基于马尔科夫链模型的定时假锁检测方法,提出了一种适用于高阶部分响应CPM信号的盲定时同步算法.该算法通过对CPM信号的PAM脉冲进行优化处理,有效减少了匹配滤波器以及网格状态的数目,同时使用辅助定时误差检测器和假锁检测器来实时监测假锁现象.理论分析和仿真结果表明,对于四阶部分响应CPM信号,在低信噪比并存在较大初始定时误差条件下,该算法也能够实现精确快速的定时同步.

Blind Timing Synchronization Algorithm Based on the PAM Decomposition for M-ary Partial-Response CPM Signals

To solve the issues of the poor performance and false lock in the blind timing synchronization for M-ary partial-response continuous phase modulation(CPM) signals,a new PAM-based timing synchronization scheme was developed from the perspective of pulse amplitude modulation(PAM) decomposition.A novel blind timing synchronization algorithm for M-ary partial-response CPM signals was proposed on the basis of the combination of this scheme and timing false lock detection based on Markov chain model.The algorithm reduced the number of matched filters and trellis states by optimizing the PAM pulse.Simultaneously,an auxiliary timing error detector and a false lock detector were used to monitor the appearance of false lock in real time.The analysis and simulation results show that the proposed algorithm provides accurate and rapid synchronization under low SNR and large initial timing error condition.