Transmitting and receiving method, in particular for detection of an ID transmitter

• US 20030016140A1
• Filed: 09/09/2002
• Published: 01/23/2003
• Est. Priority Date: 03/09/2000
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Siemens AG
• Inventors: Bernard Brillon, Alain Marc, Piesch, Wolfgang, Hofbeck, Klaus, llg, Johannes
• Granted Patent: US 7,023,321 B2
• Time in Patent Office: Days
• US Class Current: 340/825.72
• CPC Class Codes: G07C 2009/0038 whereby the wake-up circuit is situated in the keyless data carrier
• 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 9/00309 operated with bidirectional data transmission between data carrier and locks

Abstract

The invention relates to a request signal that is transmitted between a first and an additional transmitting and receiving device by means of a bi-directional first communications path. According to said request signal, a second communications path is established for a predetermined time interval and the receiving power in the additional transmitting and receiving device is measured by means of a measuring device.

Claims

1. A method for transmitting and receiving signals between at least one first transmitting and receiving device and at least one further transmitting and receiving device, in particular for unlocking and/or locking a vehicle,

a) with the presence of the further transmitting and receiving device being monitored by the first transmitting and receiving device by means of a bidirectional first communication path,

b) the first transmitting and receiving device transmitting a request signal via the first communication path on detection of the further transmitting and receiving device of this further transmitting and receiving device,

c) a second communication path being set up for a predetermined time interval between the first and the further transmitting and receiving device as a function of this request signal, and

d) the reception power level in the further transmitting and receiving devices being measured by means of a measurement device.

2. The method as claimed in claim 1, wherein the measurement result is transmitted via the first communication path to the first transmitting and receiving device.

3. The method as claimed in claim 1, wherein the first transmitting and receiving device or the further transmitting and receiving device evaluates the measurement result by means of an evaluation unit.

4. The method as claimed in claim 1, wherein the first and second communication paths use different frequency bands.

5. The method as claimed in claim 1, wherein a measurement amplifier unit is connected in the further transmitting and receiving device for setting up the second communication paths.

6. The method as claimed in claim 1, wherein the start and duration of the predetermined time interval are derived from the information content of the request signal.

7. The method as claimed in claim 1, wherein the second communication path uses the LF band.

8. The method as claimed in claim 1, wherein the second communication path is unidirectional.

9. The method as claimed in claim 1, wherein, in order to identify the position of the further transmitting and receiving device, steps a) to d) are repeated a number of times using a different transmission power and/or physically different transmission areas.

10. The method as claimed in claim 9, characterized in that the measurement results are evaluated in the first transmitting and receiving device by means of an evaluation unit.

11. The method as claimed in claim 10, characterized in that the evaluation unit evaluates the measurement results for detection of the further transmitting and receiving device by means of a fixed table.

13. The transmitting and receiving device as claimed in claim 12, wherein the first transmitting unit and the first receiving unit are in the form of a RF transmitter and RF receiver.

14. The transmitting and receiving device as claimed in claim 12, wherein the further transmitting or receiving unit is in the form of an LF transmitter or LF receiver.

16. The arrangement as claimed in claim 15, wherein the first transmitting and receiving device has an LF transmitter as the further transmitting and/or receiving unit, and the further transmitting and receiving device has an LF receiver as a further transmitting and/or receiving unit.

12. A transmitting and receiving device having a first transmitting and a first receiving unit for a first communication path with at least one further transmitting and receiving device, wherein the transmitting and receiving device has at least one further transmitting and/or receiving unit which can be switched on and off and has a measurement device in order to measure the reception power of a further transmitting and receiving device.

15. An arrangement comprising at least a first transmitting and a first receiving unit for a first communication path and at least one further transmitting and receiving device which can be switched off.