Receiving circuit and associated signal processing method

The present invention provides a receiving circuit, wherein the receiving circuit comprises a first ADC, an attenuator, a second ADC, a harmonic signal generator and an output circuit. In the operation of the receiving circuit, the first ADC performs an analog-to-digital converting operation upon an analog input signal to generate a first digital input signal, the attenuator attenuates a strength of the analog input signal to generate an attenuated analog input signal, the second ADC performs the analog-to-digital converting operation upon the attenuated analog input signal to generate a second digital input signal, the harmonic signal generator generates at least one harmonic signal according to the second digital input signal, and the output circuits cancels harmonic components of the first digital input signal by using the at least one harmonic signal to generate an output signal.