Algorithm of improving vertical resolution of digital storage oscilloscope

Abstract

Vertical resolution is a significant indicator of digital storage oscilloscope (DSO) and the key to improving it is to increase digitalizing bits and lower noise. Averaging is a common digital processing method to improve signal to noise ratio (SNR) and the effective number of bits (ENOB). However, its effect is sometimes limited by the gross error in quantization and the nonperiodic of signal. An information entropy-based data fusion and average-based decimation filtering algorithm is proposed in this paper to improve the resolution of oscilloscope. For either periodic or nonperiodic signal, resolution is improved through eliminating gross error in quantization by data fusion utilizing the maximum entropy of sample data, and with further noise filtering via average-based decimation under the premise of oversampling. No subjective assumptions and constraints are added to the signal in the whole process, and without any impact on the analog bandwidth of oscilloscope under actual sampling rate.