Patent ID: 11899096
Assignee: DENSO CORPORATION
Field: Measurement (Instruments)
Classification: CPC G  H  B  E | IPC B  G  H

Claim 10:
11. A transmission control method executed by a transmission control device, which is mounted on a vehicle and drives a plurality of antennas to detect a position of a portable device relative to the vehicle using a wireless communication between the portable device and the plurality of antennas, the plurality of antennas being arranged at respective positions of the vehicle and having different transmission ranges from one another, and the portable device being carried by a user, the transmission control method comprising:
transmitting, with use of a carrier wave from a first transmission antenna, a genuine code that activates the portable device and a first burst signal following the genuine code, and the first transmission antenna being one of the plurality of antennas; and
transmitting, with use of a carrier wave from a second transmission antenna, a second burst signal having a 180 degrees shifted phase from the first burst signal concurrently with a transmission of the first burst signal from the first transmission antenna, and the second transmission antenna being one of the plurality of antennas and having a transmission range that does not overlap with a transmission range of the first transmission antenna.