Method and system for resource allocation in relay enhanced cellular systems

• US 8,428,608 B2
• Filed: 07/03/2008
• Issued: 04/23/2013
• Est. Priority Date: 12/21/2007
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Liu, Yong, Ngo, Chiu
• Primary Examiner(s): Brandt, Christopher M
• Application Number:
  US12/167,990
• Publication Number:
  US 20090163220A1
• Time in Patent Office: 1,755 Days
• Field of Search: 455/450, 455/451, 455/452.1, 455/452.2, 455/453, 370/315
• US Class Current: 455/452.2
• 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 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

A method and system for allocating resources for a relay enhanced cellular communication system including a base station, one or more mobile stations and one or more relay stations, is provided. Resource allocation involves allocating subcarriers to one or more access communication links between mobile stations and their serving stations, to meet proportional data rate constraints for the access communication links while improving subcarrier spectrum utilization, and allocating subcarriers to one or more relay communication links between the base station and relay stations to meet proportional data rate constraints for the relay communication links while improving subcarrier spectrum utilization. Further, communication periods are scheduled for access links in access zones and relay links in relay zones. Balancing of communication resources allocated to the access links and relay links may be performed by balancing both subcarrier allocation and scheduling periods.

Claims

1. A method of allocating resources for a relay enhanced cellular communication system including a base station, one or more mobile stations and one or more relay stations, comprising:

assigning communication resources including subcarrier frequencies and time periods by;

allocating subcarriers to one or more access communication links between mobile stations and their serving stations and between base stations and their direct mobile stations, to meet proportional data rate constraints of mobile stations while improving subcarrier spectrum utilization;

allocating subcarriers to one or more relay communication links between the base station and relay stations to meet proportional data rate constraints of relay cells while improving subcarrier spectrum utilization;

scheduling communication periods for access links in access zones and relay links in relay zones;

selectively adjusting the scheduled communication periods for access zones and relay zones for providing coarse balancing of the resources allocated to the access links and the resources allocated to the relay links; and

adjusting subcarriers among relay links for refining balancing of resource allocation between access links and relay links.

2. The method of claim 1, wherein assigning communication resources further includes balancing communication resources allocated to the access links and relay links by balancing both subcarrier allocation and scheduling periods.

3. The method of claim 2, wherein the serving stations include base stations and relay stations, such that some “

indirect”

mobile stations communicate with the base station via relay stations;

while the direct mobile stations communicate directly with the base station without relying on relay stations.

4. The method of claim 3, wherein allocating resources further includes adjusting the scheduling periods of access zones and relay zones to balance the resources allocated to the access links and relay links, wherein scheduling periods comprise communication periods.

5. The method of claim 2, wherein allocating resources further includes adjusting resource allocations in both the frequency domain and time domain to optimize system throughput, balance multiple-hop links, and meet proportional data rate constraints.

6. The method of claim 2, wherein allocating resources further includes applying scheduling period adjustment to access zones and/or relay zones to achieve a coarse balance between access links and relay links, wherein if the average resource on access links is over-balanced, the access zone is shortened and the relay zone period is lengthened accordingly.

7. The method of claim 2, wherein allocating resources further includes applying scheduling period adjustment to access zones and/or relay zones to achieve a coarse balance between access links and relay links, wherein if the average resource on relay links is over-balanced, the relay zone is shortened and the access zone period is lengthened accordingly.

8. The method of claim 2, wherein allocating resources further includes adjusting subcarrier allocations among relay links to refine the balancing between access links and relay links.

9. The method of claim 1, wherein adjusting the access zone length and relay zone length is based on average frequency resource status of access zones and relay zones.

10. The method of claim 9, wherein refined balancing between access links and relay links is achieved based on individual balancing between access links and relay links.

11. The method of claim 1, further comprising:

applying scheduling period adjustment to access zones and/or relay zones for achieving a coarse balance between access links and relay links based on adjusting access zone period length and relay zone period length.

12. The method of claim 1, further comprising upon coarsely balancing communication links between base stations and relay stations and communication links between relay stations and mobile stations, performing balance checking for each individual communication link between base stations and relay stations against its corresponding relay station.

13. The method of claim 12, wherein if one or more communication links between the base stations and relay stations are over-balanced, while one or more other communication links between the base stations and relay stations are under-balanced, moving subcarriers from the overbalanced communication links between the base stations and relay stations to the under-balanced communication links between the base stations and relay stations.

14. An apparatus for allocating resources for a relay enhanced cellular communication system including a base station, one or more mobile stations and one or more relay stations, comprising:

an optimization module configured for assigning communication resources including subcarrier frequencies and time periods by;

allocating subcarriers to one or more access communication links between mobile stations and their serving stations and between base stations and their direct mobile stations, to meet proportional data rate constraints of mobile stations while improving subcarrier spectrum utilization;

allocating subcarriers to one or more relay communication links between the base station and relay stations to meet proportional data rate constraints of relay cells while improving subcarrier spectrum utilization; and

scheduling communication periods for access links in access zones and relay links in relay zones;

wherein the optimization module includes a balancing module configured for;

selectively adjusting the scheduled communication periods for access zones and relay zones for providing coarse balancing of the resources allocated to the access links and the resources allocated to the relay links; and

adjusting subcarriers among relay links for refining balancing of resource allocation between access links and relay links.

15. The apparatus of claim 14, wherein the balancing module is further configured for balancing communication resources allocated to the access links and relay links by balancing both subcarrier allocation and scheduling periods.

16. The apparatus of claim 15, wherein the serving stations include base stations and relay stations, such that some “

indirect”

mobile stations communicate with the base station via relay stations;

while the direct mobile stations communicate directly with the base station without relying on relay stations.

17. The apparatus of claim 16, wherein the balancing module is further configured for adjusting the scheduling periods of access zones and relay zones to balance the resources allocated to the access links and relay links.

18. The apparatus of claim 15, wherein the balancing module is further configured for adjusting resource allocations in both the frequency domain and time domain to optimize system throughput, balance multiple-hop links, and meet proportional data rate constraints.

19. The apparatus of claim 16, wherein the balancing module is further configured for applying scheduling period adjustment to access zones and/or relay zones for achieving a coarse balance between access links and relay links, wherein if the average resource on access links is over-balanced, the access zone is shortened and the relay zone period is lengthened accordingly.

20. The apparatus of claim 16, wherein the balancing module is further configured for applying scheduling period adjustment to access zones and/or relay zones for achieving a coarse balance between access links and relay links, wherein if the average resource on relay links is over-balanced, the relay zone is shortened and the access zone period is lengthened accordingly.

21. The apparatus of claim 16, wherein the balancing module is further configured for adjusting subcarrier allocations among relay links to refine the balancing between access links and relay links.

22. The apparatus of claim 16, wherein the optimization module further includes an analyzing module configured for determining link throughput and resource balance status of the relay links and access links.

23. The apparatus of claim 14, wherein the optimization module includes a balancing module configured for applying scheduling period adjustment to access zones and/or relay zones for achieving a coarse balance between access links and relay links based on adjusting access zone period length and relay zone period length.

24. A relay enhanced cellular communication system, comprising:

a base station, one or more mobile stations and one or more relay stations;

a controller configured for allocating resources, the controller comprising an optimization module and a balancing module,

wherein the optimization module is configured for assigning communication resources including subcarrier frequencies and time periods by;

allocating subcarriers to one or more access communication links between mobile stations and their serving stations and between base stations and their direct mobile stations, to meet proportional data rate constraints for the access communication links while improving subcarrier spectrum utilization;

allocating subcarriers to one or more relay communication links between the base station and relay stations to meet proportional data rate constraints for the relay communication links while improving subcarrier spectrum utilization; and

scheduling communication periods for access links in access zones and relay links in relay zones,

wherein the balancing module is configured for applying scheduling period adjustment to access zones and/or relay zones for achieving a coarse balance between access links and relay links based on adjusting access zone length and relay zone length, and adjusting subcarriers among relay links for refining balancing of resource allocation between access links and relay links.

25. The system of claim 24, wherein the balancing module is further configured for balancing communication resources allocated to the access links and relay links by balancing both subcarrier allocation and scheduling periods.

26. The system of claim 25, wherein the serving stations include base stations and relay stations, such that some “

indirect”

mobile stations communicate with the base station via relay stations;

while the direct mobile stations communicate directly with the base station without relying on relay stations.

27. The system of claim 26, wherein the balancing module is further configured for adjusting the scheduling periods of access zones and relay zones to balance the resources allocated to the access links and relay links.

28. The system of claim 25, wherein the balancing module is further configured for adjusting resource allocations in both the frequency domain and time domain to optimize system throughput, balance multiple-hop links, and meet proportional data rate constraints.

29. The system of claim 25, wherein the balancing module is further configured for applying scheduling period adjustment to access zones and/or relay zones for achieving a coarse balance between access links and relay links, wherein if the average resource on access links is over-balanced, the access zone is shortened and the relay zone period is lengthened accordingly.

30. The system of claim 25, wherein the balancing module is further configured for applying scheduling period adjustment to access zones and/or relay zones for achieving a coarse balance between access links and relay links, wherein if the average resource on the relay link is over-balanced, the relay zone is shortened and the access zone period is lengthened accordingly.

31. The system of claim 25, wherein the balancing module is further configured for adjusting subcarrier allocations among relay links to refine the balancing between access links and relay links.

32. The system of claim 25, wherein the optimization module further includes an analyzing module configured for determining link throughput and resource balance status of the relay links and access links.