一种初相注入式快速符号同步算法

A Fast Symbol Synchronization Algorithm Based on Initial Phase Presetting

在非合作信号分析中,接收机的采样频率通常与发送信号的符号速率之间不存在整数或者近似整数倍的关系,且要求定时同步捕获时间短。文中借助符号速率估计算法的结果对数控振荡器(NCO)进行初始化,利用NCO实现基带信号的采样率变换,从而满足平方滤波算法对过采样率为整数的要求,并由平方滤波算法得到时钟初相的估计值,实现了Gardner算法下时钟初相的注入,使得定时环路快速入锁。文中对初相注入的方法进行了详细的公式推导、计算机仿真和工程应用介绍,证实了该方法的有效性。

In the analysis of non-cooperative signals,the sampling frequency of the analysis receiver usually does not have an integer or approximately integral multiple relationship with the symbol rate of the transmitted signal,and the receiver is required to use a short time for timing synchronization acquisition.The numerical control oscillator(NCO)was initialized with the result of the symbol rate estimation algorithm,and the sampling rate conversion of the baseband signal was realized by using NCO to meet the requirement of the square filtering algorithm for the oversampling rate to be an integer.The estimated value of the initial phase of the clock was obtained by the square filtering algorithm,and the presetting of the initial phase of the clock under Gardner algorithm was realized,which makes the timing loop lock quickly.The method of initial phase presetting was deduced in detail in this article,computer simulation and practical application have confirmed the effectiveness of the method.