NON-CONTACT RF ID SYSTEM COMMUNICATION METHOD, NON-CONTACT RF ID SYSTEM, TRANSMITTER, AND RECEIVER

摘要

A communication method of a non-contact RF ID system using first, second, and third waveforms. The first and second waveforms are each composed of a basic waveform having a state transition, a rise or fall, in its generally central waveform portion. The third waveform is composed of basic waveforms each having a state transition in its generally central waveform portion, and the state transition occurs only in the generally central waveform portion of each basic waveform. When communication is carried out by using the first and second waveforms, and if the state transition occurs in a portion other than the generally central waveform portion, the third waveform can be used for the communication in place of the first and second waveforms.