DISTANCE ESTIMATE METHOD, WIRELESS DEVICE USING THE METHOD, AND WIRELESS COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To recognize whether the attenuation of receive field strength is resulted from a distance or the other cause.

SOLUTION: In a signal processing unit 40 of a radio device 10, the strength of a receive signal from a radio device as a communication object is measured in a predetermined cycle. In a memory unit 46, the measured strength is stored. In a comparator 48, it is determined that the distance from the radio device as the communication object becomes long if the measured strength is smaller than a threshold and the strength stored sequentially in the memory unit 46 is attenuated continuously in a predetermined period. A function control unit 50 informs validated results.

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