Method of signal processing using polling and related analog-to-digital converting system

An analog-to-digital converter system, comprising:

• an analog-to-digital converter configured to convert an analog signal into a digital signal;
• and
• a signal processor coupled to the analog-to-digital converter, and configured to perform signal processing to the digital signal to generate a delegate value, wherein the signal processing comprises:
• determining a candidate interval corresponding to multiple sampling points in a sampling space of the digital signal, wherein the candidate interval is one of multiple candidate intervals;
• calculating numbers of sampling points corresponding to each of the multiple candidate intervals to determine a delegate candidate interval;
• and
• calculating a delegate value of the sampling space according to a number of sampling points corresponding to the delegate candidate interval and values of the sampling points corresponding to the delegate candidate interval.