Method and apparatus for measuring distance using low clock rate signal
First Claim
1. A method of measuring a distance, comprising:
- transmitting predetermined radio waves;
generating a first clock signal having a clock frequency b and counting N3 a number of clocks of the first clock signal;
generating a second clock signal having a clock frequency a and delaying the second clock signal until the transmitted radio waves are received to generate a delayed second clock signal;
counting N1 a number of clocks of the delayed second clock signal having the clock frequency a; and
measuring the distance using the count values N1, N3 of the clock signals having the clock frequencies a and b.
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Accused Products
Abstract
Provided is an apparatus and a method of measuring a distance between devices using a low clock frequency signal. The apparatus includes clock frequency generators, counters, a controller and a calculator for determining the distance based on clock signal overlap. Radio waves are transmitted and a number of clocks of a clock signal having a clock frequency b are counted, and if the transmitted radio waves are received again, a number of clocks of a clock signal having a clock frequency a are counted. If the clock signals having the clock frequencies a and b overlap with each other, counting of the numbers of the clocks of the clock signals having the frequencies b and a stops, and the distance is measured using the count values of the clock signals having the clock frequencies a and b. As a result, number of clocks of clock signals having low clock frequencies with a uniform difference can be counted to precisely measure a distance.
17 Citations
14 Claims
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1. A method of measuring a distance, comprising:
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transmitting predetermined radio waves;
generating a first clock signal having a clock frequency b and counting N3 a number of clocks of the first clock signal;
generating a second clock signal having a clock frequency a and delaying the second clock signal until the transmitted radio waves are received to generate a delayed second clock signal;
counting N1 a number of clocks of the delayed second clock signal having the clock frequency a; and
measuring the distance using the count values N1, N3 of the clock signals having the clock frequencies a and b. - View Dependent Claims (2, 3, 4, 5, 6, 13)
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7. An apparatus for measuring a distance between devices, comprising:
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a clock signal generator that generates a first clock signal having a clock frequency b and a second clock signal having a clock frequency a. a first counter that transmits radio waves of the first clock signal and counts N3 a number of clocks of the first clock signal;
a delayer that delays a second clock signal having a clock frequency a;
a second counter that counts N1 a number of clocks of the second clock signal delayed by the delayer;
a controller that determines when the transmitted radio waves are received and instructs the second counter to count the clocks of the second clock signal delayed; and
a calculator that calculates the distance between devices using count N1 and count N3. - View Dependent Claims (8, 9, 10, 11, 12, 14)
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Specification