Patent ID: 8170148

Claim:
A demodulation circuit, comprising: a first circuit, configured to perform bandpass filtering on input signals; a second circuit, configured to increase gains of signals generated by the first circuit after the bandpass filtering; a third circuit, configured to extract pulse signals from signals output from the second circuit; and a fourth circuit, comprising: a first unit, configured to count the pulse signals extracted by the third circuit; a second unit, connected with the first unit, and configured to perform a data decision based on the counting according to a determined demodulation scheme, and output demodulated data; and a component, connected with the second unit, and configured to record label information for the demodulation scheme; wherein the performing the data decision comprises one of the following two ways: if the input signals are amplitude shift keying (ASK) signals and the label information implies that the ASK signals are to be demodulated, the second unit judges whether original data has no pulses or contains continual pulses through a counting value in a predefined time, so as to restore the demodulated data; and if the input signals are frequency shift keying (FSK) signals and the label information implies that the FSK signals are to be demodulated, the second unit judges whether the original data is pulses in a first frequency or pulses in a second frequency through a counting value in the predefined time, so as to restore the demodulated data.