ELECTRONIC KEY SYSTEM AND METHOD

摘要

An electronic key system and a method thereof are provided to improve response by reducing time for achieving synchronization in despreading. An electronic key system includes a portable device(2), an in-vehicle LF(Low Frequency) transmitter(1), and an in-vehicle LF receiver. The portable device is carried by a user. The in-vehicle LF transmitter and receiver are mounted to a vehicle and perform radio communication with the portable device to obtain authentication of the portable device for performing various control on the vehicle. The in-vehicle LF transmitter transmits a synchronization signal when transmitting an LF radio signal to the portable device. The portable device transmits an RF(Radio Frequency) radio signal to the in-vehicle LF receiver with a spread spectrum method. The portable device synchronizes a period of a spread code with a period of a spread code used in the in-vehicle LF receiver by adjusting the period of the spread code based on the synchronization signal.