DEVICE, METHOD, AND PROGRAM FOR INTERFERENCE DETERMINATION, DATA READING APPARATUS, AND RFID SYSTEM

摘要

PROBLEM TO BE SOLVED: To select an optimal response coding system and perform communications in an environment in which radio wave environment changes every moment.

SOLUTION: A carrier sensing part 14 performs carrier sensing. A radio wave environment information recording part 24 stores detection values of each frequency channel detected in a past predetermined period by the carrier sensing. A comparator 16 compares a predetermined threshold with the detection values of each frequency channel in the past predetermined period stored by the recording part 24, and determines for each channel whether all of the detection values in the past predetermined period are equal to or lower than the threshold value. A controller 19 judges by a processor that frequency channels determined by the comparator 16 that all of the detection values in the past predetermined period are equal to or lower than the threshold, are frequency channels where electric waves do not interfere. Moreover, the controller 19 determines a response coding system to ought to use, depending on which frequency channels out of the individual frequency channels are judged to be frequency channels where electric waves do not interfere.

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