| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electronic key system for a vehicle, which can analyze radio signals transmitted and received between a vehicle onboard unit and a portable machine even in the case where spread spectrum communication is adopted as a wireless communication method. <P>SOLUTION: In the electronic key system of a vehicle, the execution of various vehicle controls by the vehicle onboard unit 10 is permitted by transmitting and receiving request signals Sr and response signals Sa between the vehicle onboard unit 10 and the portable machine 20. When the vehicle onboard unit 10 and the portable machine 20 transmits and receives the response signals Sa, the response signals Sa are FSK-modulated and the FSK-modulated response signals Sa are spread-modulated, and the modulated response signals Sa are transmitted and received by the vehicle onboard unit 10 and the portable machine 20. A transmission mode of a transmitting set 22 is switched from a transmission mode of transmitting the spread-modulated response signals Sa to a transmission mode of transmitting the FSK-modulated response signals Sa based on the reception of a communication mode switching signal, transmitted from an inspection machine, by the portable machine 20. <P>COPYRIGHT: (C)2011,JPO&INPIT |
