PORTABLE-DEVICE POSITION DETERMINATION SYSTEM, PORTABLE-DEVICE POSITION DETERMINATION METHOD, AND PORTABLE-DEVICE POSITION DETERMINATION APPARATUS
First Claim
1. A portable-device position determination system comprising:
- a portable device that is configured to be possessed by a user; and
an in-vehicle device that is mounted on a vehicle and conducts wireless communication with the portable device,wherein the in-vehicle device transmits a request signal to the portable device,wherein the portable device detects a received signal intensity of the request signal to send back the received signal intensity to the in-vehicle device,wherein the in-vehicle device compares the received signal intensity of the request signal detected by the portable device to a threshold to determine a position of the portable device,wherein the in-vehicle device includes;
a transmission controller that generates the request signal, supplies an electric power to a transmitting antenna, and transmits the request signal from the transmitting antenna;
a current detector that detects a current passed through the transmitting antenna when the request signal is transmitted; and
a threshold changing part that changes the threshold based on the current detected by the current detector.
1 Assignment
0 Petitions
Accused Products
Abstract
A portable-device position determination system has a portable device that is configured to be possessed by a user, and an in-vehicle device that is mounted on a vehicle and conducts wireless communication with the portable device. The in-vehicle device transmits a request signal to the portable device. The portable device detects a received signal intensity of the request signal to send back the received signal intensity to the in-vehicle device. The in-vehicle device compares the received signal intensity of the request signal detected by the portable device to a threshold to determine a position of the portable device. The in-vehicle device includes a transmission controller that generates the request signal, supplies an electric power to a transmitting antenna, and transmits the request signal from the transmitting antenna, and a current detector that detects a current passed through the transmitting antenna when the request signal is transmitted.
-
Citations
10 Claims
-
1. A portable-device position determination system comprising:
-
a portable device that is configured to be possessed by a user; and an in-vehicle device that is mounted on a vehicle and conducts wireless communication with the portable device, wherein the in-vehicle device transmits a request signal to the portable device, wherein the portable device detects a received signal intensity of the request signal to send back the received signal intensity to the in-vehicle device, wherein the in-vehicle device compares the received signal intensity of the request signal detected by the portable device to a threshold to determine a position of the portable device, wherein the in-vehicle device includes; a transmission controller that generates the request signal, supplies an electric power to a transmitting antenna, and transmits the request signal from the transmitting antenna; a current detector that detects a current passed through the transmitting antenna when the request signal is transmitted; and a threshold changing part that changes the threshold based on the current detected by the current detector. - View Dependent Claims (2, 3)
-
-
4. A portable-device position determination method in which an in-vehicle device mounted on a vehicle conducts wireless communication with a portable device possessed by a user to transmit a request signal to the portable device, comprising:
-
detecting via the portable device a received signal intensity of the request signal to send back the received signal intensity to the in-vehicle device; comparing via the in-vehicle device the received signal intensity of the request signal detected by the portable device to a threshold to determine a position of the portable device; generating via the in-vehicle device the request signal; supplying via the in-vehicle device an electric power to a transmitting antenna; transmitting via the in-vehicle device the request signal from the transmitting antenna; detecting via the in-vehicle device a current passed through the transmitting antenna when the request signal is transmitted; and changing via the in-vehicle device the threshold based on the detected current. - View Dependent Claims (5, 6)
-
-
7. A portable-device position determination apparatus that is of an in-vehicle device mounted on a vehicle,
wherein the portable-device position determination apparatus: -
conducts wireless communication with a portable device configured to be possessed by a user to transmit a request signal to the portable device, receives a received signal intensity of the request signal detected by the portable device from the portable device, and compares the received signal intensity to a threshold to determine a position of the portable device, wherein the portable-device position determination apparatus comprises; a transmission controller that generates the request signal, supplies an electric power to a transmitting antenna, and transmits the request signal from the transmitting antenna; a current detector that detects a current passed through the transmitting antenna when the request signal is transmitted; and a threshold changing part that changes the threshold based on the current detected by the current detector. - View Dependent Claims (8, 9, 10)
-
Specification