DEVICE AND METHOD FOR MEASURING DISTANCE

摘要

PROBLEM TO BE SOLVED: To measure a distance between two transceivers by a simplified structure.SOLUTION: A transmission signal S5 including a first state A and a second state B in which a frequency or a phase of carrier waves is changed every half cycle of a first reference signal S1 based on the first reference signal is transmitted from a first transceiver to a second transceiver. The second transceiver demodulates the receiving signal from the first transceiver to detect the first state and the second state. During a period of a half cycle in which reception periods of the first and second states are equal, return carrier waves of a predetermined frequency are transmitted to the first transceiver. The first transceiver demodulates the transmission signal S5 by the return carrier waves S6 received from the second transceiver, and a distance is obtained based on a length of at least one of periods with two different states relating to the frequency or the phase of the demodulated signal.