| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for appropriately demodulating an ASK signal including a noise in a frequency that is close to a carrier frequency, at low cost.SOLUTION: An edge detection part 11 detects an edge of an ASK signal. A margin period setting part 12 sets a margin period including a time in which detection of a subsequent edge is predicted on the basis of a time in which a leading edge is detected. A detection standby mode setting part 13 sets a detection standby mode in response to arrival of a start time of the margin period and cancels the detection standby mode in response to the detection of the edge or arrival of a finish time of the margin period. An abnormal edge count part 17 counts the number of edges which are detected while the detection standby mode is not set, among edges which are detected during a demodulation object period. In the case where the number of edges is equal to or more than a predetermined number, a binary data determination part 16 determines that demodulation data are abnormal, prolongs the margin period and appropriately decodes the ASK signal.SELECTED DRAWING: Figure 2 |
