System and method for uplink inter cell interference coordination in a wireless access system

1. A method for providing uplink inter cell interference coordination in a wireless access system, the method comprising:

categorizing users in the wireless access system, wherein the wireless access system comprises a plurality of controllers, and wherein categorizing users comprises grouping users in accordance with a distance between each controller in the plurality of controllers and users served by the controller;

selecting a resource allocation plan in accordance with the categorized users;

allocating, by one or more of the controllers, resources to the users in the wireless access system in accordance with the selected resource allocation plan; and

receiving transmissions from the users.

2. The method of claim 1 , wherein categorizing users further comprises grouping users in accordance with a distance between each user and controllers other than the user's serving controller.

3. The method of claim 1 , wherein categorizing users comprises at each controller,

receiving a signal strength measurement from each user served by the controller;

measuring a signal strength of each user signal;

estimating an interference measure to each neighboring controller for each user in accordance with the received signal strength measurement and the measured signal strength; and

grouping each user in accordance with the estimated interference measure.

4. The method of claim 1 , wherein categorizing users comprises at each controller,

requesting neighboring controllers measure interference due to a transmission of a user;

receiving the measured interference from the neighboring controllers; and

grouping the user in accordance with the measured interference.

5. The method of claim 4 , further comprising, combining the measured interference from the neighboring controllers.

6. The method of claim 1 , wherein selecting a resource allocation plan in accordance with the categorized users comprises selecting one of a reuse-3 resource allocation plan, a multiple-ring fractional frequency reuse (FFR) resource allocation plan, a multiple reuse resource allocation plan, a two-ring FFR resource allocation plan, and

wherein a reuse-1 resource allocation plan is used prior to selecting the resource allocation plan in accordance with the categorized users.

7. The method of claim 6 , wherein selecting the resource allocation plan comprises:

selecting the reuse-3 resource allocation plan when there are no center cell users in the wireless access system;

selecting the multiple-ring fractional frequency reuse (FFR) resource allocation plan when the wireless access system can support more than a two-ring FFR resource allocation;

selecting the multiple reuse resource allocation plan when the wireless access system cannot support a two-ring FFR resource allocation; and

selecting the two-ring FFR resource allocation plan when the wireless access system cannot support only a two-ring FFR resource allocation.

8. The method of claim 1 , wherein the categorization of users is performed in accordance with a combined throughput of users being served by neighboring controllers.

9. A method for providing uplink inter cell interference coordination in a wireless access system, the method comprising:

categorizing users in the wireless access system;

selecting a resource allocation plan in accordance with the categorized users;

allocating, by a communications controller, resources to the users in the wireless access system in accordance with the selected resource allocation plan; and

receiving transmissions from the users,

wherein selecting the resource allocation plan comprises:

selecting a reuse-3 resource allocation plan in response to determining that there are no center cell users in the wireless access system;

selecting a multiple-ring fractional frequency reuse (FFR) resource allocation plan in response to determining that the wireless access system can support more than a two-ring FFR resource allocation;

selecting a multiple reuse resource allocation plan in response to determining that the wireless access system cannot support a two-ring FFR resource allocation; and

selecting a two-ring FFR resource allocation plan in response to determining that the wireless access system cannot support only a two-ring FFR resource allocation.

10. The method of claim 9 , wherein the wireless access system comprises the communications controller and a plurality of neighboring controllers, and wherein the method further comprises coordinating resource allocations with the neighboring controllers.

11. The method of claim 9 , wherein the multiple reuse resource allocation plan comprises a reuse- 1 allocation of a frequency band, a reuse-2 allocation of the frequency band, and a reuse-3 allocation of the frequency band or a reuse-1 allocation of the frequency band and a reuse-3 allocation of the frequency band.

12. The method of claim 9 , wherein determining that there are no center cell users comprises evaluating:

δ

=

γ

1

+

2

⁢

γ

-

1

-

1

,

where γ is a measured signal to noise ratio and δ is interference over thermal noise.

13. The method of claim 9 , wherein determining that the wireless access system can support more than a two-ring FFR comprises:

computing a signal-to-noise ratio distribution in accordance with reported downlink pilots and measured uplink pilots;

dividing the users into N groups, where N is an integer value greater than two (2), in response to determining that a range of the signal-to-noise ratio distribution is greater than a threshold; and

determining that the wireless access system can support N-ring FFR if 72 1→2 η 2→1 <1+γ 0 is satisfied, where η i→j is an interference over thermal noise caused by user i to user j.

14. The method of claim 9 , wherein a reuse-1 resource allocation plan is used prior to selecting the resource allocation plan in accordance with the categorized users.

15. The method of claim 9 , wherein the categorization of users in the wireless access system is performed in accordance with a distance between a plurality of controllers and the users served by those controllers.

16. The method of claim 9 , wherein the categorization of users is performed in accordance with a combined throughput of users being served by neighboring controllers.

17. A method for providing uplink inter cell interference coordination in a wireless access system, the method comprising:

categorizing users in the wireless access system;

selecting a resource allocation plan in accordance with the categorized users;

allocating, by a communications controller, resources to the users in the wireless access system in accordance with the selected resource allocation plan;

receiving transmissions from the users; and

initially selecting a reuse-1 resource allocation plan.

18. The method of claim 17 , wherein selecting the resource allocation plan occurs after the reuse-1 resource allocation plan is used prior to selecting the resource allocation plan, and wherein selecting the resource allocation plan comprises:

selecting a reuse-3 resource allocation plan when there are no center cell users in the wireless access system;

selecting a multiple-ring fractional frequency reuse (FFR) resource allocation plan when the wireless access system can support more than a two-ring FFR resource allocation;

selecting a multiple reuse resource allocation plan when the wireless access system cannot support a two-ring FFR resource allocation; and

selecting a two-ring FFR resource allocation plan when the wireless access system cannot support only a two-ring FFR resource allocation.

19. The method of claim 17 , wherein the categorization of users in the wireless access system is performed in accordance with a distance between a plurality of controllers and the users served by those controllers.

20. The method of claim 17 , wherein the categorization of users is performed in accordance with a combined throughput of users being served by neighboring controllers.

21. A method for providing uplink inter cell interference coordination in a wireless access system, the method comprising:

categorizing users in the wireless access system;

selecting a resource allocation plan in accordance with the categorized users;

allocating, by a communications controller, resources to the users in the wireless access system in accordance with the selected resource allocation plan; and

receiving transmissions from the users,

wherein categorizing users in the wireless access system is in accordance with a throughput of users in the wireless access system,

wherein the wireless access system comprises a plurality of controllers,

wherein each controller servers a potentially different number of users, and

wherein the categorization of users in the wireless access system is in accordance with a combined throughput of users being served by neighboring controllers.

22. The method of claim 21 , wherein the categorization of users in the wireless access system comprises:

comparing a combined throughput of users being served by neighboring controllers with a throughput of individual users; and

categorizing the users in accordance with the comparison.

23. The method of claim 21 , wherein selecting a resource allocation plan in accordance with the categorized users comprises selecting one of a reuse-3 resource allocation plan, a multiple-ring fractional frequency reuse (FFR) resource allocation plan, a multiple reuse resource allocation plan, and a two-ring FFR resource allocation plan, and wherein a reuse-1 resource allocation plan is used prior to selecting the resource allocation plan in accordance with the categorized users.

24. The method of claim 23 , wherein selecting the resource allocation plan comprises:

selecting the reuse-3 resource allocation plan when there are no center cell users in the wireless access system;

selecting the multiple-ring FFR resource allocation plan when the wireless access system can support more than a two-ring FFR resource allocation;

selecting the multiple reuse resource allocation plan when the wireless access system cannot support a two-ring FFR resource allocation; and

selecting the two-ring FFR resource allocation plan when the wireless access system cannot support only a two-ring FFR resource allocation.

25. The method of claim 21 , wherein the categorization of users in the wireless access system is performed in accordance with a distance between the plurality of controllers and the users served by those controllers.