Vehicle Transmission Control Device Antenna Crosstalk Prevention
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Solution Overview
Problem
Existing vehicle authentication systems are prone to erroneous detection of a portable device's position due to crosstalk from driven antennas and radiation noise generated by transmission control devices, especially when the device is close to the transmission control device or at longer distances, leading to incorrect positioning inside or outside the vehicle compartment.
Innovation Solution
A transmission control device that drives multiple antennas with different transmission ranges, transmitting a genuine code and noise determination burst signals at distinct time points to prevent erroneous detection by ensuring the portable device receives radiation noises from all antennas, allowing it to determine if all noise signals are received, thereby preventing false position detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple antennas are driven to detect portable device position, then position detection coverage is improved, but crosstalk between antennas causes erroneous detection
Solution Approach 1:
The patent divides the antenna system into a genuine transmission antenna and remaining antennas. The genuine transmission antenna transmits the genuine code, while the remaining antennas transmit noise determination purpose burst signals at different time points. This segmentation allows the system to maintain multiple antenna coverage while preventing crosstalk-induced erroneous detection by clearly separating the functions of different antennas.
Solution Approach 2:
The patent transmits the noise determination purpose burst signal from the genuine transmission antenna before transmitting the genuine code. This preliminary action allows the portable device to determine the presence of radiation noise in advance, enabling it to correctly identify the genuine code even when crosstalk from other antennas is present during code transmission.
2Length of stationary object
If transmission range is extended to detect distant devices, then detection range is improved, but radiation noise causes erroneous detection
Solution Approach 1:
The patent introduces the noise determination purpose burst signal as an intermediary element. This signal serves as a reference that helps the portable device distinguish between genuine transmission signals and radiation noise. By comparing the received burst signals with the expected pattern, the portable device can identify and filter out noise, enabling accurate position detection even at extended transmission ranges where noise levels are higher.
3Area of stationary object
If antennas are positioned to cover all areas, then detection coverage is improved, but overlapping transmission ranges cause crosstalk
Solution Approach 1:
The patent employs periodic action by transmitting noise determination purpose burst signals from different antennas at different time points in a sequential manner. The genuine transmission antenna transmits its burst signal at one time point, while remaining antennas transmit their burst signals at shifted time points. This time-division approach allows multiple antennas to operate simultaneously with overlapping coverage areas without causing crosstalk, as each antenna transmits at a distinct time.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively prevents erroneous detection of the portable device's position by ensuring the portable device can differentiate between genuine code and noise signals, enhancing the accuracy of position detection within the vehicle compartment.
Implementation Method 1
transmit, with use of a carrier wave, a genuine code for activating a portable device and a noise determination purpose burst signal
Data Source
AI summary
A transmission control device that drives multiple antennas having different transmission ranges controls a genuine transmission antenna among the multiple antennas to transmit, with use of a carrier wave, a genuine code for activating a portable device and a noise determination purpose burst signal for determining a noise in the portable device after the transmission of the genuine code, and controls each antenna of a remaining antenna group, which includes remaining antennas except the genuine transmission antenna, to transmit the noise determination purpose burst signal at a transmission time point, which is set different from one another and shifted from a transmission time point of the noise determination purpose burst signal from the genuine transmission antenna. The transmission ranges of the multiple antennas including the genuine transmission antenna are set to not have a common area.