全数字差拍频率测量方法  

All-digital beat-frequency measurement method for precise frequency standard comparison

作　　者：朱祥维[1] 龚航[1] 黄新明[1] 欧钢[1] 

机构地区：[1]国防科技大学电子科学与工程学院,湖南长沙410073

出　　处：《中南大学学报（自然科学版）》2015年第4期1296-1301,共6页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(61403413)(Project(61403413)~~

摘　　要：针对目前卫星导航系统中原子频率标准的高精度频率测量需求,提出一种全数字差拍频率测量方法,对被测标准频率信号直接进行数字采样,以解决模拟差拍频率测量方法受温度影响大的问题。利用最大似然估计实现相位估计,采用相位差分完成频率测量,并引入小波阈值去噪处理进一步提高相位估计精度。研究结果表明:当测量间隔为1 s、估计点数为3 000时的频率测量精度为2.0×10-14/s,经过小波阈值去噪处理后频率测量精度达到10-15/s量级。An all-digital beat-frequency measurement method was proposed to meet high measurement requirement of atomic oscillators widely used in global position system. The measurement frequency signal was directly sampled without any analogue processing to avoid the influence on environment. The method adopted the maximum likelihood estimation（MLE） to acquire phase estimation values, and frequency measurement was realized by phase difference estimation. The wavelet threshold de-noising was introduced to improve the precision of phase estimation. Performance of the method was analyzed and verified by simulation. The results show that when the frequency measurement precision reaches 2.0×10^-14 /s and measurement points reaches 3 000, the frequency measurement precision reaches 10^-15 /s order with wavelet threshold de-noising.

关 键 词：频率测量 差拍 相位估计 小波阈值去噪 

分 类 号：TF803.21[冶金工程—有色金属冶金]