一种低信噪比正弦信号高精度频率测量方法

摘要

The effect of noise to frequency measurements on the condition of lowSNR is studied,on the basis of multi-cycle synchronization frequency measurement,method of an multi-multi-cycle synchronization frequency measurement is put forward and the formula of frequency measurement & error calculation is deduced. At the end,the implementation method and calculationformula based on STM32 MCU are given. Experimentresult shows that for the low SNR sinusoidal signal,the method introduced can effectively suppress noise,and increases the accuracy of frequency measurement.%在研究噪声对低信噪比正弦信号频率测量的影响、分析触发误差对多周期同步频率测量影响的基础上，提出了一种多-多周期同步频率测量方法，推导了频率测量计算公式和误差计算公式，并对两种测频方法的触发误差做了对比分析；最后给出了用STM32单片机实现多-多周期同步频率测量的方法。实验表明：该方法能有效压制噪声，提高低信噪比正弦信号频率测量精度。