Using geographical coordinates to determine mobile station time position for synchronization during diversity handover

• US 20020072370A1
• Filed: 12/03/2001
• Published: 06/13/2002
• Est. Priority Date: 12/04/2000
• Status: Active Grant

• Current Assignee: Unwired Planet LLC (JP Morgan Chase & Co)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Jonsson, Erik, Johansson, Staffan
• Granted Patent: US 6,954,644 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 36/322 by location data

Abstract

A telecommunications system comprises a source base station (BS_S), a destination base station (BS_D) having a synchronization searcher (s), and a synchronization start position determination unit (101) which establishes a start position (SP) of a synchronization search window for the synchronization searcher of the destination station. The synchronization search window detects, for synchronization purposes, a transmission of the specified mobile station received at the destination base Station during a handover of a connection involving the specified mobile station from the source station to the destination base station. In accordance with an aspect of the present invention, the synchronization start position determination unit establishes the start position of the synchronization search window with reference to a calculated distance of the mobile station from the destination base station.

Claims

1. For use in a code division multiple access communication system having a source base station and a destination base station where a specified mobile station establishes a connection with the source base station, a method comprising:

initiating a handover of the connection involving the specified mobile station to the destination base station; and

establishing a start position of a synchronization search window for the specified mobile station with reference to a perceived geographical location of the mobile station.

2. The method of claim 1, wherein the perceived geographical location is a geographical coordinate position of the mobile station.

3. The method of claim 1, wherein the step of establishing the start position involves determining a distance from the base station to the perceived geographical location of the mobile station.

4. The method of claim 1, further comprising determining the perceived geographical location of the mobile station at a radio network control node of a code division multiple access communication system.

5. The method of claim 4, further comprising communicating the start time position from the radio network controller node to the destination base station.

6. For use in a code division multiple access communication system having a source base station and a destination base station where a specified mobile station establishes a connection with the source base station, a method comprising:

initiating a handover of the connection involving the specified mobile station to the destination base station; and

establishing a start position of a synchronization search window for the specified mobile station with reference to a calculated distance of the mobile station from the destination base station.

7. The method of claim 6, wherein the step of establishing the start position includes calculating a distance from a geographical coordinate position of the mobile station to a geographical coordinate position of the destination base station.

8. The method of claim 6, further comprising calculating the distance of the mobile station from the destination base station at a radio network control node of a code division multiple access communication system.

9. The method of claim 8, further comprising communicating the start time position from the radio network controller node to the destination base station.

10. A telecommunications system comprising:

a source base station;

a destination base station having a synchronization searcher;

a synchronization start position determination unit which establishes a start position of a synchronization search window for the synchronization searcher of the destination station, the synchronization search window being used to detect a transmission of a specified mobile station received at the destination base station during a handover of a connection involving the specified mobile station from the source station to the destination base station, the synchronization start position determination unit establishing the start position of the synchronization search window with reference to a perceived geographical location of the mobile station.

11. The apparatus of claim 10, wherein the perceived geographical location is a geographical coordinate position of the mobile station.

12. The apparatus of claim 10, wherein the synchronization start position determination unit establishes the start position using by calculating a distance from the base station to the perceived geographical location of the mobile station.

14. The apparatus of claim 13, wherein the synchronization start position determination unit establishes the start position by calculating a distance from a geographical coordinate position of the mobile station to a geographical coordinate position of the destination base station.

15. The apparatus of claim 14, wherein the synchronization start position determination unit calculates the distance of the mobile station from the destination base station at a radio network control node of a code division multiple access communication system.

16. The apparatus of claim 15, wherein the radio network controller node communicates the start time position to the destination base station.

18. The apparatus of claim 17, wherein the perceived geographical location is a geographical coordinate position of the mobile station.

19. The apparatus of claim 17, wherein the synchronization start position determination unit establishes the start position using by calculating a distance from the base station to the perceived geographical location of the mobile station.

13. A telecommunications system comprising:

a source base station;

a destination base station having a synchronization searcher;

a synchronization start position determination unit which establishes a start position of a synchronization search window for the synchronization searcher of the destination station, the synchronization search window being used to detect a transmission of a specified mobile station received at the destination base station during a handover of a connection involving the specified mobile station from a source base station to the destination base station, the synchronization start position determination unit establishing the start position of the synchronization search window with reference to a calculated distance of the mobile station from the destination base station.

17. A synchronization start position determination unit situated at a node of code division multiple access communication system comprising, the synchronization start position determination unit serving to establish a start position of a synchronization search window for a synchronization searcher of a destination base station, the synchronization search window being used to detect a transmission of a specified mobile station received at the destination base station during a handover of a connection involving the specified mobile station from a source base station to the destination base station, the synchronization start position determination unit establishing the start position of the synchronization search window with reference to a perceived geographical location of the mobile station.

20. A synchronization start position determination unit situated at a node of code division multiple access communication system comprising, the synchronization start position determination unit serving to establish a start position of a synchronization search window for a synchronization searcher of a destination base station, the synchronization search window being used to detect a transmission of a specified mobile station received at the destination base station during a handover of a connection involving the specified mobile station from a source base station to the destination base station, the synchronization start position determination unit establishing the start position of the synchronization search window with reference to a calculated distance of the mobile station from the destination base station.

21. The apparatus of claim 20, wherein the synchronization start position determination unit establishes the start position by calculating a distance from a geographical coordinate position of the mobile station to a geographical coordinate position of the destination base station.

22. The apparatus of claim 20, wherein the synchronization start position determination unit calculates the distance of the mobile station from the destination base station at a radio network control node of a code division multiple access communication system.

23. The apparatus of claim 22, wherein the radio network controller node communicates the start time position to the destination base station.