Method for searching for signals among interference signals in a multi-channel radio receiver

• US 8,588,716 B2
• Filed: 01/24/2007
• Issued: 11/19/2013
• Est. Priority Date: 02/06/2006
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive AG (Continental AG)
• Inventors: Kursawe, Christian, Reisinger, Thomas, Stolz, Franz, Schmid, Jrgen
• Primary Examiner(s): Vuong, Quochien B
• Application Number:
  US11/910,617
• Publication Number:
  US 20100029232A1
• Time in Patent Office: 2,491 Days
• Field of Search: 455/41.2, 455/41.3, 455/161.3, 455/334, 455/343.1, 455/343.2, 455/343.4, 455/574, 340/438, 340/442, 340/539.1, 340/870.16
• US Class Current: 455/161.3
• CPC Class Codes: H04B 17/318 Received signal strength

Abstract

In a method for searching for signals among interference signals in a multi-channel radio receiver, at least two different data signals are transmitted on at least one physical channel of a radio system to a common receiver. The search for a signal is initiated on any channel, starting with a sequential search of a useful signal by measuring the current signal strength in the form of the RSSI value; a search is made for a signal criterion of the signal and when said criterion has been identified, the measured RSSI value is compared with a predefined RSSI threshold value; if the RSSI threshold value is exceeded, the search for a signal is switched to a search for a data frame and if a data frame is found, the useful data is read; if no signal criterion is identified, if the RSSI threshold value is not exceeded and if no data frame is found, the procedure is interrupted and a new search operation is initiated once a new RSSI threshold value has been defined. The invention is particularly suitable for radio transmission systems in motor vehicles to implement RKE and TPMS functions and for multi-channel transmissions, used for example in remote metering and remote control systems.

Claims

1. A method for searching for signals among interference signals in a multi-channel radio receiver in which at least two different data signals are transmitted on at least one physical channel of a radio system to a common receiver, the method which comprises:

starting from a sequential search for a useful signal, initiating a signal search on any given channel by measuring a current signal strength to determine a measured RSSI value;

searching for a signal criterion for the useful signal being sought on the given channel and, after the signal criterion is identified, comparing the measured RSSI value with a predetermined RSSI threshold value;

if the measured RSSI value exceeds the RSSI threshold value, switching from a signal search to a data frame search on the given channel and, if the data frame search is successful, reading the useful data; and

if no data frame is found on the given channel, aborting the search on the given channel, defining a new RSSI threshold value for the given channel, and initiating a new search process.

2. The method according to claim 1, which comprises, after receipt of the data frame has ended, updating the RSSI threshold value.

3. The method according to claim 1, which comprises deactivating or ignoring a channel, in which interference signals are identified.

4. The method according to claim 1, which comprises changing a sequence in which the channels are searched.

5. The method according to claim 1, which comprises searching all channels and subsequently classifying the channels according to a quality of signal detection on the different channels.

6. The method according to claim 1, which comprises reducing a sensitivity of the receiver.

7. The method according to claim 1, which comprises adapting the RSSI threshold value to an interference level determined in the process.

8. The method according to claim 1, which comprises defining the RSSI threshold value as a threshold value range with an upper boundary and a lower boundary.

9. The method according to claim 1, wherein the signal criterion is a bit pattern.