ADAPTIVE RESOURCE ALLOCATION PROTOCOL FOR NEWLY JOINING RELAY STATIONS IN RELAY ENHANCED CELLULAR SYSTEMS

• US 20100260113A1
• Filed: 04/10/2009
• Published: 10/14/2010
• Est. Priority Date: 04/10/2009
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Liu, Yong, Ngo, Chiu
• Application Number:
  US12/422,107
• Publication Number:
  US 20100260113A1
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 7/15542 Selecting at relay station its transmit and receive resources selection of wireless resources by user or terminal H04W72/02; arrangements affording multiple use of the transmission path by two-dimensional division of the resources H04L5/0003, or by allocating sub-channels H04L5/003
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• 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 88/04 adapted for relaying to or from another terminal or user

Abstract

A method and system for allocating subcarrier frequency resources in a relay enhanced cellular communication system including a base station, multiple relay stations and mobile stations. One implementation involves, for a new relay station joining the relay enhanced cellular communication system, identifying mobile stations that the new relay station can service, and assigning sufficient resources to the new relay station to accommodate minimum data rate requirements of the access links of the identified mobile station. The resources are assigned by adjusting existing resource assignments essentially in an optimal manner while reducing impact on existing stations in the relay enhanced cellular communication system.

Claims

1. A method of allocating subcarrier frequency resources in a relay enhanced cellular communication system including a base station, multiple relay stations and mobile stations, comprising:

for a new relay station joining the relay enhanced cellular communication system;

identifying mobile stations that the new relay station can service; and

assigning sufficient resources to the new relay station to accommodate minimum data rate requirements of the access links of the identified mobile stations;

wherein said resources are assigned by adjusting existing resource assignments essentially in an optimal manner while reducing impact on existing stations in the relay enhanced cellular communication system.

2. The method of claim 1 wherein identifying mobile stations that the new relay station can service further comprises:

determining local communication channel conditions for the new relay station; and

based on the local channel conditions of the new relay station, identifying a mobile station that may be serviced by the new relay station to accommodate minimum data rate requirements of the access links of the identified mobile station.

3. The method of claim 2 wherein:

identifying mobile stations that may be serviced by the new relay station further comprises;

dividing the mobile stations near the new relay station into multiple types including;

first type;

a mobile station outside the coverage of the base station and other relay stations;

second type;

mobile station directly served by the base station; and

third type;

a mobile station served by adjacent relay stations; and

assigning sufficient resources to the new relay station further comprises;

if the new relay station can more efficiently utilize resources previously assigned to second and third type mobile stations, then adjusting resource assignments such that the resources previously assigned to the second and third type mobile stations are reallocated to the new relay station.

4. The method of claim 3 wherein assigning sufficient resources to the new relay station further comprises:

detecting resources essentially immediately available to the new relay station;

classifying the detected resources into multiple categories based on quality of said resources including;

a clean resource comprising;

a residual resource not yet allocated, a resource used by the base station to support second type mobile stations not reusable by other relay stations, and a resource exclusively used by adjacent relay stations to support third type mobile stations not reused by other relay stations;

a reusable resource comprising;

a resource used by a remote relay station and reusable by the new relay station; and

a dirty resource comprising;

a resource used by an adjacent relay station to support third type mobile stations while the resource is also reused by another adjacent relay station to support non-third type mobile stations, thereby not reusable by the new relay station.

5. The method of claim 4 wherein adjusting existing resource assignments essentially in an optimal manner comprises:

adjusting existing resource assignments based on said resource categories, to provide sufficient resources to the new relay cell to meet minimum data rate requirements of access links of the identified mobile stations while maintaining the resource supplies to other relay cells.

6. The method of claim 5 wherein adjusting existing resource assignments further comprises:

adjusting resources starting from clean resources, by assigning clean resources first to second and third type mobile stations to meet their minimum data rate requirements; and

assigning remaining clean resources to first type mobile stations to meet their minimum data rate requirements.

7. The method of claim 6 wherein adjusting existing resource assignments further comprises:

if clean resources are not sufficient to meet the minimum data rate requirements of the second and third type mobile stations, then reallocating reusable resources that were originally assigned to third type mobile stations to second and third type mobile stations in the new relay cell; and

allocating reusable resources to the new relay cell if reuse improves the overall system throughput, such that if the reallocation of the reusable resources impairs the throughput of the remote relay cells sharing the same resources, clean resources assigned exclusively to second and third type mobile are reused in relay cells impacted by the resource reuse reallocation, wherein clean resources are reused in the relay cells only if the reuse can improve the overall system throughput.

8. The method of claim 7 wherein adjusting existing resource assignments further comprises:

if the reusable resources, together with the clean resources, are still not sufficient to meet the minimum data rate requirements of the second and third type mobile stations, then detecting additional reusable resources from remote relay cells, starting from a remote relay cell that generates the least co-channel interference with the new relay cell;

assigning the additional reusable resources to second and third type mobile stations for the new relay cell until all such mobile stations meet their minimum data rate requirements.

9. A relay enhanced cellular communication system, comprising:

a base station, multiple mobile stations and a relay station;

a resource controller configured for adaptive resource allocation for a new relay station joining the relay enhanced cellular communication system, the resource controller comprising;

a resource identification module configured for identifying mobile stations that the new relay station can service; and

a resource allocation module configured for assigning sufficient resources to the new relay station to accommodate minimum data rate requirements of the access links of the identified mobile stations, wherein said resources are assigned by adjusting existing resource assignments essentially in an optimal manner while reducing impact on existing stations in the relay enhanced cellular communication system.

10. The system of claim 9 wherein the resource identification module is further configured for identifying mobile stations that the new relay station can service by:

determining local communication channel conditions for the new relay station; and

based on the local channel conditions of the new relay station, identifying mobile stations that may be serviced by the new relay station to accommodate minimum data rate requirements of the access links of the identified mobile stations.

11. The system of claim 10 wherein:

the resource identification module is further configured for identifying mobile stations that may be serviced by the new relay station by dividing the mobile stations near the new relay station into multiple types including;

first type;

a mobile station outside the coverage of the base station and other relay stations;

second type;

mobile station directly served by the base station; and

third type;

a mobile station served by adjacent relay stations; and

the allocation module is further configured for assigning sufficient resources to the new relay station, such that if the new relay station can more efficiently utilize resources previously assigned to second and third type mobile stations, then the allocation module adjusts resource assignments such that the resources previously assigned to the second and third type mobile stations are reallocated to the new relay station.

12. The system of claim 11 wherein the allocation module is further configured for assigning sufficient resources to the new relay station by detecting resources essentially immediately available to the new relay station, the system further including a classification module configured for classifying the detected resources into multiple categories based on quality of said resources including:

a clean resource comprising;

a residual resource not yet allocated, a resource used by the base station to support second type mobile stations not reusable by other relay stations, and a resource exclusively used by adjacent relay stations to support third type mobile stations not reused by other relay stations;

a reusable resource comprising;

a resource used by a remote relay station and reusable by the new relay station; and

a dirty resource comprising;

a resource used by an adjacent relay station to support third type mobile stations while the resource is also reused by another adjacent relay station to support non-third type mobile stations, thereby not reusable by the new relay station.

13. The system of claim 12 wherein the allocation module is further configured for adjusting existing resource assignments essentially in an optimal manner by adjusting existing resource assignments based on said resource categories, to provide sufficient resources to the new relay cell to meet minimum data rate requirements of access links of the identified mobile stations while maintaining the resource supplies to other relay cells.

14. The system of claim 13 wherein the allocation module is further configured for adjusting existing resource assignments by adjusting resources starting from clean resources, by assigning clean resources first to second and third type mobile stations to meet their minimum data rate requirements;

and assigning remaining clean resources to first type mobile stations to meet their minimum data rate requirements.

15. The system of claim 14 wherein the allocation module is further configured for adjusting existing resource assignments such that:

if clean resources are not sufficient to meet the minimum data rate requirements of the second and third type mobile stations, then the allocation module reallocates reusable resources that were originally assigned to third type mobile stations to second and third type mobile stations in the new relay cell; and

the allocation module allocates reusable resources to the new relay cell if reuse improves the overall system throughput, such that if the reallocation of the reusable resources impairs the throughput of the remote relay cells sharing the same resources, clean resources assigned exclusively to second and third type mobile are reused in relay cells impacted by the resource reuse reallocation, wherein clean resources are reused in the relay cells only if the reuse can improve the overall system throughput.

16. The system of claim 15 wherein the allocation module is further configured for adjusting existing resource assignments such that:

if the reusable resources, together with the clean resources, are still not sufficient to meet the minimum data rate requirements of the second and third type mobile stations, then the allocation module detects additional reusable resources from remote relay cells, starting from a remote relay cell that generates the least co-channel interference with the new relay cell; and

the allocation modules assigns the additional reusable resources to second and third type mobile stations for the new relay cell until all such mobile stations meet their minimum data rate requirements.

17. A computer program product for adaptive resource allocation for a new relay station joining a relay enhanced cellular communication system, the computer program product comprising:

a computer usable medium having computer readable program code embodied therewith, wherein the computer readable program when executed on the computer causes the computer to;

for a new relay station joining the relay enhanced cellular communication system;

identify mobile stations that the new relay station can service; and

assign sufficient resources to the new relay station to accommodate minimum data rate requirements of the access links of the identified mobile stations;

wherein said resources are assigned by adjusting existing resource assignments essentially in an optimal manner while reducing impact on existing stations in the relay enhanced cellular communication system.

18. The computer program product of claim 17 further comprising computer readable program code for identifying a mobile station that the new relay station can service further comprises by:

determining local communication channel conditions for the new relay station; and

based on the local channel conditions of the new relay station, identifying a mobile station that may be serviced by the new relay station to accommodate minimum data rate requirements of the access links of the identified mobile station.

19. The computer program product of claim 18 further comprising computer readable program code for:

identifying mobile stations that may be serviced by the new relay station by;

dividing the mobile stations near the new relay station into multiple types including;

first type;

a mobile station outside the coverage of the base station and other relay stations;

second type;

mobile station directly served by the base station; and

third type;

a mobile station served by adjacent relay stations; and

assigning sufficient resources to the new relay station by;

if the new relay station can more efficiently utilize resources previously assigned to second and third type mobile stations, then adjusting resource assignments such that the resources previously assigned to the second and third type mobile stations are reallocated to the new relay station.

20. The computer program product of claim 19 further comprising computer readable program code for assigning sufficient resources to the new relay station by:

detecting resources essentially immediately available to the new relay station;

classifying the detected resources into multiple categories based on quality of said resources including;

a clean resource comprising;

a residual resource not yet allocated, a resource used by the base station to support second type mobile stations not reusable by other relay stations, and a resource exclusively used by adjacent relay stations to support third type mobile stations not reused by other relay stations;

a reusable resource comprising;

a resource used by a remote relay station and reusable by the new relay station; and

a dirty resource comprising;

a resource used by an adjacent relay station to support third type mobile stations while the resource is also reused by another adjacent relay station to support non-third type mobile stations, thereby not reusable by the new relay station.

21. The computer program product of claim 20 further comprising computer readable program code for adjusting existing resource assignments essentially in an optimal manner by:

adjusting existing resource assignments based on said resource categories, to provide sufficient resources to the new relay cell to meet minimum data rate requirements of access links of the identified mobile stations while maintaining the resource supplies to other relay cells.

22. The computer program product of claim 21 further comprising computer readable program code for adjusting existing resource assignments further by:

adjusting resources starting from clean resources, by assigning clean resources first to second and third type mobile stations to meet their minimum data rate requirements;

assigning remaining clean resources to first type mobile stations to meet their minimum data rate requirements.

23. The computer program product of claim 22 further comprising computer readable program code for adjusting existing resource assignments further by:

if clean resources are not sufficient to meet the minimum data rate requirements of the second and third type mobile stations, then reallocating reusable resources that were originally assigned to third type mobile stations to second and third type mobile stations in the new relay cell;

allocating reusable resources to the new relay cell if reuse improves the overall system throughput, such that if the reallocation of the reusable resources impairs the throughput of the remote relay cells sharing the same resources, clean resources assigned exclusively to second and third type mobile are reused in relay cells impacted by the resource reuse reallocation, wherein clean resources are reused in the relay cells only if the reuse can improve the overall system throughput.

24. The computer program product of claim 23 further comprising computer readable program code for adjusting existing resource assignments by:

if the reusable resources, together with the clean resources, are still not sufficient to meet the minimum data rate requirements of the second and third type mobile stations, then detecting additional reusable resources from remote relay cells, starting from a remote relay cell that generates the least co-channel interference with the new relay cell;

assigning the additional reusable resources to second and third type mobile stations for the new relay cell until all such mobile stations meet their minimum data rate requirements.