Wireless communication method and system for minimizing interference by determining mobile station zone locations and potential conflicts between cell zones

• US 7,046,655 B2
• Filed: 12/30/2002
• Issued: 05/16/2006
• Est. Priority Date: 08/15/2002
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Marinier, Paul, Roy, Vincent
• Primary Examiner(s): Nguyen, Steven HD
• Application Number:
  US10/334,459
• Publication Number:
  US 20040032850A1
• Time in Patent Office: 1,233 Days
• Field of Search: 370/310, 370/328, 370/329, 370/339, 370/441, 370/442, 370/479, 370/480, 370/498, 370/280, 370/275, 370/276, 370/277, 370/465, 370/330, 370/347, 370/377, 370/336, 455/422, 455/450, 455/452, 455/456, 455/509, 455/513, 455/515, 455/517, 455/523, 455/69, 455/562, 455/522, 455/562.1, 455/452.2, 455447-448
• US Class Current: 370/347
• CPC Class Codes: H04W 16/00 Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
• CPC Class Codes: H04W 16/02 Resource partitioning among network components, e.g. reuse partitioning
• CPC Class Codes: H04W 16/12 Fixed resource partitioning
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• CPC Class Codes: H04W 92/20 between access points

Abstract

A wireless communication method and system for minimizing severe interference to one or more wireless transmit/receive unit (WTRUs). A plurality of non-overlapping zones (e.g., an inner zone and an outer zone) is defined for each cell of a wireless multi-cell communication system, such as a time division duplex (TDD) system. Information regarding potential conflicts between the non-overlapping cell zones is obtained. Each potential conflict indicates that there is a high likelihood of one of the WTRUs using a specific time slot for transmitting in a zone of one cell causing severe interference to a second one of the WTRUs using the specific time slot for receiving in a zone of another (i.e., a different) cell. Time slot usage (e.g., uplink, downlink or none) is then determined on a zone-by-zone basis using the obtained information to minimize interference caused by a conflicting uplink assignment or a conflicting downlink assignment.

Claims

1. A method of minimizing interference in a wireless multi-cell communication system that serves a plurality of wireless transmit/receive units (WTRUs), the method comprising:

(a) defining a plurality of non-overlapping zones in a conflicting zone lookup table for each cell in the system;

(b) obtaining information from the conflicting zone lookup table regarding potential conflicts between the non-overlapping cell zones, wherein the conflicting zone lookup table specifically identifies each of the zones of the cells, and each potential conflict indicates that there is a high likelihood of one of the WTRUs using a specific time slot for transmitting in one of the specifically identified zones of one cell causing severe interference to a second one of the WTRUs using the specific time slot for receiving in one of the specifically identified zones of another cell; and

(c) determining time slot usage on a zone-by-zone basis using the information obtained from the conflicting zone lookup table to minimize interference caused by a conflicting uplink assignment or a conflicting downlink assignment.

2. The method of claim 1 wherein the wireless multi-cell communication system assigns channels to the WTRUs.

3. The method of claim 1 wherein a current zone location is determined for each of the WTRUs based on a signal delay measurement.

4. The method of claim 3 wherein the determination of the current zone location for each of the WTRUs is further based on a received power measurement.

5. The method of claim 3 wherein the current zone location identifies a specific cell of the system in which the WTRU is located.

6. The method of claim 3 wherein the non-overlapping zones include an inner zone and an outer zone, and the current zone location indicates whether the WTRU is located in the inner zone or the outer zone.

7. The method of claim 1 wherein the wireless multi-cell communication system is a time division duplex (TDD) system.

8. The method of claim 1 wherein the specific time slot can be simultaneously used by WTRUs in zones of different cells if the conflicting zone lookup table indicates that the different cell zones do not conflict.

9. The method of claim 1 wherein a slow dynamic channel allocation (SDCA) process is used to determine the best use of each time slot in each cell zone based on constraints imposed by conflicting zones indicated by the conflicting zone lookup table, and average traffic characteristics.

10. A wireless multi-cell communication system comprising:

(a) a plurality of wireless transmit/receive units (WTRUs);

(b) a plurality of cells, each of the cells having a plurality of non-overlapping zones;

(c) means for obtaining information from a conflicting zone lookup table regarding potential conflicts between the non-overlapping cell zones, wherein the conflicting zone lookup table specifically identifies each of the zones of the cells, and each potential conflict indicates that there is a high likelihood of one of the WTRUs using a specific time slot for transmitting in one of the specifically identified zones of one cell causing severe interference to a second one of the WTRUs using the specific time slot for receiving in one of the specifically identified zones of another cell; and

(d) means for determining time slot usage on a zone-by-zone basis using the information obtained from the conflicting zone lookup table to minimize interference caused by a conflicting uplink assignment or a conflicting downlink assignment.

11. The system of claim 10 wherein the wireless multi-cell communication system assigns channels to the WTRUs.

12. The system of claim 10 wherein a current zone location is determined for each of the WTRUs based on a signal delay measurement.

13. The system of claim 12 wherein the determination of the current zone location for each of the WTRUs is further based on a received power measurement.

14. The system of claim 12 wherein the current zone location identifies a specific cell of the system in which the WTRU is located.

15. The system of claim 12 wherein the non-overlapping zones include an inner zone and an outer zone, and the current zone location indicates whether the WTRU is located in the inner zone or the outer zone.

16. The system of claim 10 wherein the wireless multi-cell communication system is a time division duplex (TDD) system.

17. The system of claim 10 wherein the specific time slot can be simultaneously used by WTRUs in zones of different cells if the conflicting zone lookup table indicates that the different cell zones do not conflict.

18. The system of claim 10 wherein a slow dynamic channel allocation (SDCA) process is used to determine the best use of each time slot in each cell zone based on constraints imposed by conflicting zones indicated by the conflicting zone lookup table, and average traffic characteristics.