Frequency Measurement with Short Time Data Phase Difference Method
XU Bo-tao · Radio Engineering of China · 2007
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.