Signal processing system and method thereof

A signal processing method, adapted to an analog-to-digital converter outputting a digital signal, the signal processing method comprising:

• using an adjustable filter to filter the digital signal, to generate a filtered signal;
• calculating and outputting a signal difference value between the digital signal and the filtered signal;
• comparing the signal difference value with a preset threshold value, to generate a comparison result, and then generating a selection signal and a bandwidth adjustment signal according to the comparison result;
• according to the selection signal, outputting one of the digital signal and the filtered signal;
• and
• adjusting a bandwidth of the adjustable filter according to the bandwidth adjustment signal.

A signal processing system, adapted to an analog-to-digital converter, the signal processing system comprising:

• a plurality of filters configured to receive a digital signal outputted from the analog-to-digital converter, and filter the digital signal to generate a plurality of filtered signals, wherein the plurality of filters have different bandwidths;
• a signal difference calculating unit configured to calculate and output a plurality of signal difference values between the digital signal and the plurality of filtered signals, and output a minimal signal difference value among the plurality of signal difference values, and output the filtered signal corresponding to the minimal signal difference value;
• a determining unit configured to compare the minimal signal difference value with a preset threshold value to generate a comparison result, and then generate a selection signal according to the comparison result;
• and
• a selecting unit configured to receive the digital signal and the filtered signal corresponding to the minimal signal difference value, and output one of the digital signal and the filtered signal corresponding to the minimal signal difference value, according to the selection signal.

A signal processing system, adapted to an analog-to-digital converter, the signal processing system comprising:

• a plurality of filters configured to receive a digital signal outputted from the analog-to-digital converter, and filter the digital signal to generate a plurality of filtered signals, wherein the plurality of filters have different bandwidths;
• a signal difference calculating unit configured to calculate and output a plurality of signal difference values between the digital signal and the plurality of filtered signals, and output a minimal signal difference value among the plurality of signal difference values, and a filter ID code corresponding to the minimal signal difference value;
• a determining unit configured to compare the minimal signal difference value with a preset threshold value to generate a comparison result, and then generate a selection signal according to the comparison result and the filter ID code;
• and
• a selecting unit configured to receive the digital signal and the filtered signal, and output one of the digital signal and the plurality of filtered signals according to the selection signal.