Patent ID: 8369457

Claim:
A demodulation apparatus comprising: operation determination means for determining whether said demodulation apparatus operates as part of either a first device or a second device with which said demodulation apparatus communicates, said first device being configured to amplitude shift keying (ASK) modulate and transmit data, said second device being configured to load-modulate and transmit data; first demodulation control means configured such that if said demodulation apparatus is determined to operate as part of said first device, then said first demodulation control means detects a phase change of a transmitted signal generated by said second device on the basis of an in-phase signal and an orthogonal signal obtained by orthogonally detecting said transmitted signal, said first demodulation control means further demodulating data sent from said second device on the basis of the detected phase change; and second demodulation control means configured such that if said demodulation apparatus is determined to operate as part of said second device and if the communication scheme of said first device is estimated to be a predetermined communication scheme, then said second demodulation control means detects an amplitude change of a transmitted signal generated by said first device on the basis of a detection signal obtained by envelope-detecting said transmitted signal, said second demodulation control means further demodulating data sent from said second device on the basis of the detected amplitude change.