MULTI-ANTENNA SYSTEM AND METHOD FOR REMOTELY CONTROLLING A FUNCTION

• US 20070085658A1
• Filed: 10/18/2005
• Published: 04/19/2007
• Est. Priority Date: 10/18/2005
• Status: Active Grant

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Tang, Tom, King, Ronald, Turovsky, Art
• Granted Patent: US 7,683,757 B2
• Time in Patent Office: Days
• US Class Current: 340/5.720
• CPC Class Codes: B60R 25/24 using electronic identifiers containing a code not memorised by the user
• CPC Class Codes: G07C 2009/00793 by Hertzian waves
• CPC Class Codes: G07C 2209/63 Comprising locating means for detecting the position of the data carrier, i.e. within the vehicle or within a certain distance from the vehicle
• CPC Class Codes: G07C 9/00182 operated with unidirectional data transmission between data carrier and locks

Abstract

A system and method for remotely controlling a function. The system includes a transmitter and a receiver control circuit having a plurality of antennas. The transmitter transmits a wireless control signal having first and second signal portions. An antenna is selected based on the first signal portion. A function is performed when the second signal portion is received by the selected antenna and successfully decoded.

Claims

1. A system for remotely controlling a function, the system comprising:

a transmitter for transmitting a wireless control signal having a first signal portion and a second signal portion, the first signal portion being indicative of a function request; and

a receiver control circuit having a first antenna, a second antenna, and a controller for selectively enabling and disabling the first and second antennas and decoding the wireless control signal;

wherein the first antenna receives the first signal portion; and

wherein the controller enables the second antenna when the first signal portion is indicative of a function that is to be performed when the transmitter is within a first predetermined distance from the receiver, and wherein the function is performed when the second signal portion is received by the second antenna and successfully decoded.

2. The system of claim 1 wherein the controller enables the second antenna when the first signal portion is indicative of a function that is to be performed when the transmitter is within a second predetermined distance from the receiver and wherein the function is performed when the second signal portion is received by the second antenna and successfully decoded.

3. The system of claim 2 wherein the first predetermined distance is less than the second predetermined distance.

4. The system of claim 1 wherein the receiver control circuit further comprises a third antenna, and wherein the controller enables the third antenna when the first signal portion is not indicative of a function that is to be performed when the transmitter is within the second predetermined distance from the receiver, wherein the function is performed when the second signal portion is received by the first antenna and successfully decoded.

5. The system of claim 4 wherein the first antenna is a high gain antenna, the second antenna is a low gain antenna, and the third antenna is a very low gain antenna.

6. The system of claim 1 wherein the transmitter transmits the wireless control signal at a single power level.

7. The system of claim 1 wherein the receiver control circuit is disposed on a motor vehicle and the transmitter is a remote keyless entry fob.

8. The system of claim 7 wherein the remote keyless entry fob is an active remote keyless entry fob.

9. The system of claim 7 wherein the remote keyless entry fob is a passive remote keyless entry fob.

13. The method of claim 9 wherein the transmitter is part of an active remote keyless entry fob.

14. The method of claim 9 wherein the transmitter is part of a passive remote keyless entry fob.

16. The method of claim 1 wherein the vehicle-mounted receiver control circuit further comprises a third antenna that is selectively enabled and disabled by the controller and the method further comprises the steps of:

enabling the third antenna and disabling the first and second antennas when the first signal portion is indicative of a second function that is to be performed when the transmitter is within a second predetermined distance from the vehicle; and

performing the second function when the second signal portion is received by the third antenna and successfully decoded;

wherein the third antenna provides lower gain than the second antenna.

10. A method of controlling a function, the method comprising:

transmitting a wireless control signal with a transmitter, the wireless control signal having a first signal portion and a second signal portion;

receiving the first signal portion with a first antenna;

determining whether the first signal portion is indicative of a range-limited function;

enabling a second antenna when the first signal portion is indicative of a range-limited function; and

performing the range-limited function when the second signal portion is received by the second antenna and successfully decoded;

wherein the first antenna provides higher gain than the second antenna.

11. The method of claim 10 wherein the range-limited function is not performed when the second signal portion is not received by the second antenna or when the second signal portion is not properly decoded.

12. The method of claim 10 wherein the transmitter transmits the wireless control signal at a single power level.

15. A method of controlling a vehicle function with a remote keyless entry system having a remote keyless entry fob having a transmitter and a vehicle-mounted receiver control circuit that includes first and second antenna, and a controller for selectively enabling and disabling the first and second antennas, the method comprising:

transmitting a wireless control signal having a first signal portion and a second signal portion with the transmitter;

receiving the first signal portion with the first antenna;

enabling the second antenna and disabling the first antenna when the first signal portion is indicative of a first function that is to be performed when the transmitter is within a first predetermined distance from the vehicle; and

performing the first function when the second signal portion is received by the second antenna and successfully decoded;

wherein the first antenna provides higher gain than the second antenna.

17. The method of claim 15 further comprising disabling the second and third antennas when the first signal portion is not indicative of a first function that is to be performed when the transmitter is within a first predetermined distance from the vehicle or a second function that is to be performed when the transmitter is within a second predetermined distance from the vehicle.

18. The method of claim 15 wherein the first function includes at least one of locking a vehicle closure, closing a vehicle window, and starting a vehicle engine.

19. The method of claim 15 wherein the second function includes at least one of unlocking a vehicle closure and actuating a vehicle closure.

20. The method of claim 15 wherein the transmitter transmits the wireless control signal at a single power level.