Title:
SPEED MEASURING APPARATUS AND POSITION DETECTOR
Document Type and Number:
Japanese Patent JPH10148670
Kind Code:
A
Abstract:
To perform measurement of relative speed or detection of position accompanying it accurately from a frequency shift based on Doppler effect using a reference frequency of lower accuracy in radio transceiver for two-way data communications.
Frequency shift is measured for transmitting and receiving frequencies by frequency shift detectors 104, 108 in first and second radio transceivers 100, 101. An operating unit 109 in the second radio transceiver 101 adds a frequency shift data transmitted from the first radio transceiver 100 and a frequency shift data transmitted measured by the frequency shift detector 108 to offset the error of both frequency references thus determining the relative speed.
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Inventors:
TAKAI HITOSHI
URABE YOSHIO
YAMAZAKI HIDESATO
URABE YOSHIO
YAMAZAKI HIDESATO
Application Number:
JP23714297A
Publication Date:
June 02, 1998
Filing Date:
September 02, 1997
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD
International Classes:
G01S1/68; G01S13/50; G01S13/524; (IPC1-7): G01S13/50; G01S1/68; G01S13/524
Attorney, Agent or Firm:
Shiro Ogasawara