| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve location accuracy of a mobile unit, and reduce the time required for locating the mobile unit. <P>SOLUTION: An in-vehicle device 1 transmits a signal obtained by performing direct sequence spread spectrum on data signal including different antenna identification patterns with different spread codes, from antennas A-C arranged in a vehicle, according to different patterns, while gradually changing the waveform intensity, in the same period. The mobile unit 2 performs inverse spread spectrum on the received signal, extracts the antenna identification patterns included in the data signals, locates the mobile unit in the vehicle by use of the extracted antenna identification patterns, and transmits it to the in-vehicle device. <P>COPYRIGHT: (C)2013,JPO&INPIT |
