摘要
从相位差法测频的基本原理出发,考虑到直接平均相位差法不能适应低信噪比和短时数据的要求,对相位数据做解卷绕和翻转预处理,从而解决了相位跳周和频率反转的固有问题。做完预处理的相位数据,通过2种测频算法高阶相位差法和相位加权平均法,2种算法都不会出现直接平均的数据抵消,而且充分利用了相位差信息。仿真试验表明,2种算法能适应短时数据低信噪比的要求,能应用于工程实践。
According to the fundamental principle of frequency measurement by phase difference method, considering that the direct average phase difference method is not fit for the low signal-to-noise ratio and short time sample data, preprocesses of unwrapping and reversion are performed for the phase data, so the issues of phase cycle-skipping and frequency reversion are resolved. Then phase data preprocessed are applied to two frequency measurement algorithms, high order phase difference algorithm and weighted phase average algorithm. Both algorithms make full use of phase information and meet the requirement of short time low SNR data and engineering practice.
出处
《无线电工程》
2007年第4期48-50,共3页
Radio Engineering
关键词
相位差法
加权平均相位法
相位解卷绕
阈值
phase difference algorithm
weighted average phase method
phases unwrapping
threshold value
