| 摘要 |
PROBLEM TO BE SOLVED: To implement a communication system by a phase modulation signal inexpensively by achieving demodulation of a phase modulation wave by a general purpose microcomputer. SOLUTION: The phase modulation processing period of a general purpose microcomputer and the carrier wave period are approximated, the demodulation processing includes an edge detection processing of three continuous carriers, an up/down counter is incremented when an edge is detected during first edge detection, is not changed when an edge is detected during intermediate edge detection, and decremented when an edge is detected during last edge detection. The demodulation processing is decreased by one machine cycle when the up/down counter reaches an upper specified value, but increased by one machine cycle when it reaches a lower specified value, and phase demodulation processing having a processing for synchronizing with the carrier phase and a processing for detecting the carrier immediately after edge detection is performed. COPYRIGHT: (C)2007,JPO&INPIT
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