VARIABLE STRENGTH WIRELESS COMMUNICATION SYSTEM

• US 20100007462A1
• Filed: 07/10/2008
• Published: 01/14/2010
• Est. Priority Date: 07/10/2008
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: PROEFKE, David T., BIONDO, William A.
• Granted Patent: US 8,659,388 B2
• Time in Patent Office: Days
• US Class Current: 340/5.720
• CPC Class Codes: G08C 17/02 using a radio link

Abstract

A wireless communication system is provided. The communication system comprises a key fob comprising a wireless transmitter adapted to transmit a first signal having a first transmission field strength and first transmission duration, and a second signal having a second transmission field strength and second transmission duration and a vehicle comprising a wireless receiver adapted to receive the first and second signals.

Claims

1. A wireless communication system comprising:

a key fob comprising a wireless transmitter adapted to transmit a first signal having a first transmission field strength and first transmission duration, and a second signal having a second transmission field strength and second transmission duration; and

a vehicle comprising a wireless receiver adapted to receive the first and second signals.

2. The wireless communication system of claim 1, wherein the first transmission field strength is less than the second transmission field strength.

3. The wireless communication system of claim 2, wherein the first transmission field strength is between 60 and 85 dBμ

V/m.

4. The wireless communication system of claim 2, wherein the second transmission field strength is between 85 and 105 dBμ

V/m.

5. The wireless communication system of claim 1, wherein the first transmission duration is longer than the second transmission duration.

6. The wireless communication system of claim 5, wherein the first transmission duration is between 80 and 200 milliseconds.

7. The wireless communication system of claim 5, wherein the second transmission duration is between 10 and 50 milliseconds.

8. The wireless communication system of claim 1, wherein the wireless transmitter is further adapted to transmit a third signal having a third transmission field strength and third transmission duration.

9. The wireless communication system of claim 8, wherein the second transmission field strength is less than the third transmission field strength and the second transmission duration is greater than the third transmission duration.

10. The wireless communication system of claim 1, wherein the wireless receiver is adapted to detect signals at a signal detection rate, the first and second signals are transmitted at a first and second signal transmit rate, respectively, and the first and second signal transmit rates are faster than the signal detection rate.

11. A method of transmitting a wireless key fob signal comprising:

transmitting a first key fob signal at a first transmission field strength, the first signal having a first transmission duration;

transmitting a second key fob signal after the first signal, the second signal having a second transmission field strength and a second transmission duration, wherein the first transmission field strength is less than the second transmission field strength and the first transmission duration is longer than the second transmission duration.

12. The method of claim 11, wherein transmitting the first signal comprises transmitting only one cycle of the first signal before transmitting the second signal.

13. The method of claim 11, further comprising transmitting a third signal after the second signal, the third signal having a third transmission field strength and a third transmission duration, wherein the second transmission field strength is less than the third transmission field strength and the second transmission duration is greater than the third transmission duration.

14. The method of claim 13, wherein transmitting the second signal comprises transmitting at least two cycles of the second signal before transmitting the third signal.

15. The method of claim 11, further comprising receiving either of the first and second signals with a wireless receiver, the wireless receiver adapted to poll for the first and second signals.

16. The method of claim 15, further comprising performing a vehicular interaction operation in response to receiving at least one of the first and second signals.

17. The method of claim 16, wherein performing a vehicular interaction operation comprises at least one of unlocking a door of a vehicle, unlatching a hatch of a vehicle, activating an alarm of a vehicle, and adjusting a height of a window of a vehicle.

18. A wireless communication system comprising:

a wireless transmitter adapted to transmit a first signal having a first transmission field strength and a first transmission duration, and a second signal having a second transmission field strength and a second transmission duration, where the first transmission field strength is less than the second transmission field strength and the first transmission duration is greater than the second transmission duration; and

a wireless receiver adapted to detect signals at a signal detection interval and to receive the first and second signals.

19. The wireless communication system of claim 18, wherein the signal detection interval is constant.

20. The wireless communication system of claim 19, wherein the first transmission duration is longer than the signal detection interval.