基于参量模型估计的周期信号等效采样方法研究

New Equivalent Time Sampling Method Based on Parametric Model Estimation

针对现有的常规的等效时间采样方法必须具备准确的模拟触发电路,必须具备精确的定时电路或时长检测电路,并且波形重建时间长甚至不能完全重建的问题,提出一种基于参量模型估计的周期信号等效时间采样方法.该方法采用三个两两互质频率进行三轮采样,从三轮采样数据估计出被测周期信号的基频和其它参数,从而重构出被测周期信号波形.实验证明,该方法在信噪比较高时重构出被测周期信号波形的正确概率很高,重构误差很小.该方法已被成功运用到数字存储示波器的高速数据采集系统中.

A new equivalent time sampling method based on parametric model estimation is invented to solve the problem of normal equivalent time sampling method, which needs accurate trigger circuit, precision timing circuit or time measuring circuit. Sometimes the normal equivalent time sampling method even cannot wholly reconstruct the signal waveform. In the equivalent time sampling method based on parametric model estimation, three kinds of sampling clock, frequency of which are coprime each other, are adopted to sample three times. And three groups of data are acquired. The basic frequency and other parameters of the periodic signal are estimated from three groups of data. And the periodic signal waveform is reconstructed. It has been tested by experiments that the equivalent time sampling method based on parametric model estimation can accurately reconstruct the periodic signal waveform and the reconstruction error is little. The equivalent time sampling method based on .parametric model estimation has been applied in the high-speed data acquisition system of the digital storage oscilloscope successfully.