A communication signal demodulation apparatus demodulates a communication signal to generate an output signal. The communication signal demodulation apparatus includes: plural sensor circuits which sense different electrical characteristics of one same communication signal and generate corresponding sensing modulation signals respectively; plural processing filters which filter the corresponding sensing modulation signals respectively and generate corresponding filtered modulation signals respectively; plural demodulators which demodulate the plural filtered modulation signals and generate corresponding demodulation signals respectively, wherein each of the filtered modulation signals corresponds to at least one of the demodulators; and a determination circuit which receive the plural demodulation signals, determine whether each unit signal of each of the demodulation signals is correct or not according to a determination mechanism, and combine one or more correct unit signals to generate the output signal.