Abstract:
An on-vehicle device includes a determination unit, an instruction unit, and a modification unit. The determination unit determines whether to unlock doors based on a rolling code from a portable device and a reference rolling code to be collated with the rolling code. When the determination unit determines to unlock the doors, the instruction unit instructs the portable device to increase a value of the rolling code. When the portable device accepts the instruction from the instruction unit, the modification unit increases a value of the reference rolling code to be used in the determination unit.
Abstract:
This vehicular near field communication system has a configuration where a portable device receives a first signal and a second signal respectively transmitted from a vehicle-exterior antenna and a vehicle-interior antenna of an on-board instrument mounted in a vehicle, measures a first received signal strength from the first signal, measures a second received signal strength from the second signal, adds an offset to the second received signal strength, and transmits a response signal to the on-board instrument in accordance with the first received signal strength and the second received signal strength added with the offset, so as to be able to prevent a portable device from being locked in a cabin even though the portable device is shielded by a metal in the cabin.
Abstract:
A portable device performs two-way communication with an on-board device. The portable device has an operating circuit, a communication circuit, and a controller circuit. The operating circuit accepts an operation for stopping communication with the on-board device. The communication circuit receives a first signal from the on-board device and transmits to the on-board device a second signal including information on reception strength of the first signal and information on communication stop corresponding to the operation accepted by the operating circuit. When the reception strength of the first signal received by the communication circuit is less than or equal to a first threshold, the controller circuit causes the communication circuit to stop the communication with the on-board device.
Abstract:
This short-distance radio communication system for a vehicle includes an in-vehicle unit having more than one antenna and a portable unit performing radio communications with the in-vehicle unit. The in-vehicle unit transmits a first burst together with a call signal for calling the portable unit through a first antenna, and transmits a second burst subsequent to the first burst through a second antenna. The portable unit receives the signals transmitted from the in-vehicle unit, measures respective received signal strength indicators from the first burst and the second burst contained in the received signals, and responds to the in-vehicle unit according to results of comparing the respective indicators with given thresholds.