IN-VEHICLE WIRELESS SYSTEM

• US 20090322475A1
• Filed: 06/25/2009
• Published: 12/31/2009
• Est. Priority Date: 06/30/2008
• Status: Active Grant

• Current Assignee: Toyota Boshoku Kabushiki Kaisha
• Original Assignee: Toyota Boshoku Kabushiki Kaisha
• Inventors: TODA, Shigeyoshi, UNO, Hideki
• Granted Patent: US 8,570,146 B2
• Time in Patent Office: Days
• US Class Current: 340/5.64
• CPC Class Codes: H04B 7/0602 using antenna switching H04B7/0686 takes precedence; antenna beam directivity switching H01Q3/24
• CPC Class Codes: H04B 7/0817 with multiple receivers and antenna path selection
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity

Abstract

An in-vehicle wireless system, capable of operating at least in a copy mode and a transmission mode, comprises: at least one receiving unit receiving a wireless signal transmitted from a remote control transmitter and demodulates a control code signal; and at least one transmitting unit transmitting wireless signals at a plurality of carrier frequencies; and a control unit controlling so as to obtain a control code from the control code signal and store it in the copy mode, and so as to perform transmitting the modulated wireless signals at all carrier frequencies unique to a plurality of the garage door opening-closing mechanisms or the like. The receiving unit may include a detection circuit connected to a reception antenna directly.

Claims

1. An in-vehicle wireless system that is placed in a vehicle so as to control a garage door opening-closing mechanism and/or household equipment that are remotely controlled by a high-frequency wireless signal, and is capable of operating at least in a copy mode and a transmission mode,

the in-vehicle wireless system comprising:

at least one receiving unit that receives a wireless signal transmitted from a remote control transmitter for performing control on the garage door opening-closing mechanism and/or household equipment through a reception antenna, and demodulates a control code signal for performing the control from the received signal;

at least one transmitting unit that transmits wireless signals at a plurality of carrier frequencies through a transmission antenna; and

a control unit that controls the at least one receiving unit and the at least one transmitting unit,

wherein the control unit in the copy mode detects a control code from the control code signal and stores the control code, and the control unit in the transmission mode controls the transmitting unit to perform transmission of a wireless signal modulated by the stored control code, the transmission of the modulated wireless signal being performed at all carrier frequencies unique to a plurality of the garage door opening-closing mechanisms and/or household equipments in accordance with predetermined procedures.

2. The in-vehicle wireless system according to claim 1, wherein:

the wireless signal transmitted from the remote control transmitter is an ASK-modulated high-frequency signal; and

the receiving unit includes an envelope detection circuit that is connected to the reception antenna.

3. The in-vehicle wireless system according to claim 2, wherein:

the receiving unit further includes a comparator circuit that compares an output signal of the envelope detection circuit with a reference voltage; and

the control unit includes a microcontroller that has a digital input having an output signal of the comparator circuit input thereto.

4. The in-vehicle wireless system according to claim 2, wherein the control unit includes a microcontroller that has an analog input having an output signal of the envelope detection circuit input thereto.

5. The in-vehicle wireless system according to claim 1, wherein:

the control unit includes a carrier frequency setting unit that generates a frequency setting signal for selecting the carrier frequency; and

the transmitting unit includes a voltage controlled oscillator circuit that is controlled with the frequency setting signal, and an output circuit that multiplies the frequency of an output signal of the voltage controlled oscillator circuit and ASK-modulates the output signal.

6. The in-vehicle wireless system according to claim 5, wherein:

the transmitting unit further includes a plurality of transmission antennas and an antenna switching circuit that switches between the transmission antennas; and

the control unit switches between the transmission antennas to be used by outputting an antenna select signal to the antenna switching circuit.

7. The in-vehicle wireless system according to claim 6, wherein each of the transmission antennas has a different antenna center frequency or a different transmission wave polarization from the other transmission antennas.

8. The in-vehicle wireless system according to claim 1, wherein each of the transmitting units includes a transmission antenna having a different antenna center frequency or a different transmission wave polarization from transmission antennas of the other transmission units.

9. The in-vehicle wireless system according to claim 1, wherein the transmitting units transmit the wireless signals at the same carrier frequency from all the transmitting units in turn.

10. The in-vehicle wireless system according to claim 1, wherein the transmitting units simultaneously transmit the wireless signals at the different carrier frequencies.

11. The in-vehicle wireless system according to claim 1, wherein the predetermined procedures are carried out to perform transmitting the wireless signals successively in ascending or descending order of the carrier frequency.

12. The in-vehicle wireless system according to claim 10, wherein the predetermined procedures are carried out so that one of the two transmitting units performs transmitting the wireless signals successively in ascending order of the carrier frequency, and the other one of the two transmitting units performs transmitting the wireless signals successively in descending order of the carrier frequency.

13. The in-vehicle wireless system according to claim 2, wherein:

each of the receiving units has a reception antenna having a different reception sensitivity with respect to a center frequency or wave polarization from reception antennas of the other receiving units; and

the control unit detects the control code by selecting or processing the control code signals that are input from the respective receiving units.

14. The in-vehicle wireless system according to claim 6, further comprising

a transmission antenna unit that includes the transmission antenna and is located at a distance,

wherein:

the transmission antenna unit is connected to the output circuit with a high-frequency cable,

the control unit includes a circuit that superimposes the antenna select signal as a DC voltage on the high-frequency cable; and

the transmission antenna unit includes the antenna switching circuit that is activated by value of the DC voltage.

15. The in-vehicle wireless system according to claim 5, further comprising

a transmission antenna unit that includes the transmission antenna and is located at a distance,

wherein:

the transmission antenna unit is connected to the output circuit with a high-frequency cable,

the control unit includes a circuit that superimposes an impedance matching signal as a DC voltage on the high-frequency cable, the impedance matching signal being for impedance matching with the transmission antenna; and

the transmission antenna unit includes the impedance matching circuit that is activated by value of the DC voltage.

16. The in-vehicle wireless system according to claim 1, wherein the control unit receives data for updating the garage door opening-closing mechanism and/or household equipment or the control procedures through the receiving unit, and changes the carrier frequency and/or the control procedures in accordance with the data.

17. The in-vehicle wireless system according to claim 3, wherein:

the control unit includes a carrier frequency setting unit that generates a frequency setting signal for selecting the carrier frequency; and

the transmitting unit includes a voltage controlled oscillator circuit that is controlled with the frequency setting signal, and an output circuit that multiplies the frequency of an output signal of the voltage controlled oscillator circuit and ASK-modulates the output signal.

18. The in-vehicle wireless system according to claim 17, wherein the predetermined procedures are carried out to perform transmitting the wireless signals in ascending or descending order of the carrier frequency.