Self-adaptive low-pass digital filter of variable frequency signals and method thereof

The invention discloses a self-adaptive low-pass digital filter of variable frequency signals and a corresponding filtering method thereof, which can perform variable frequency filtration and real-time filtration to signals with variable frequency. The self-adaptive low-pass digital filter of variable frequency signals comprises a latch for latching input signals, a signal spectrum analyzer for analyzing input signals latched by the latch so as to obtain spectrum distribution of input signals, a signal frequency arbiter for arbitrating needed signal frequency according to the spectrum distribution received by the signal spectrum analyzer; a self-adaptive filtering frequency calculator for calculating limiting frequency of the signal frequency arbitrated by the signal frequency arbiter, and a variable limiting frequency low-pass filter for receiving input signals latched by the latch, filtering input signals according to limiting frequency sent by the self-adaptive filtering frequency calculator, and outputtin