Method for adaptively controlling and coordinating other cell interference
Disclosed is a method, and system thereof, for controlling other-cell interference by adjusting a transmit power parameter for mobile stations in neighboring cells in order to create, within a serving cell, a low interference zone associated with a set of sub-carriers which may be used by edge mobile stations within the serving cell. Rather than restricting the neighboring cells from using the set of sub-carriers associated with the low interference zone, the goal is to reduce the amount of other-cell interference the mobile stations in the neighboring cells can produce with respect to the low interference zone in the serving cell.
1. A method of controlling other-cell interference in a wireless communication system comprising the steps of:
receiving zone overload information for a neighbor cell associated with a low interference zone and a high interference zone; and
adjusting a transmit power parameter of a mobile station in a serving cell based on the received zone overload information.
2. The method of claim 1 , wherein the zone overload information indicates the low interference zone is interference overloaded if interference measurements corresponding to the low interference zone is above a low interference threshold.
3. The method of claim 1 , wherein the zone overload information indicates the high interference zone is interference overloaded if interference measurements corresponding to the high interference zone is above a high interference threshold, and the low interference threshold being a lower threshold than the high interference threshold.
4. The method of claim 1 , wherein the zone overload information indicates the low interference zone is interference overloaded if interference measurements corresponding to the low interference zone is above a low interference threshold, the zone overload information indicates the high interference zone is interference overloaded if interference measurements corresponding to the high interference zone is above a high interference threshold, and the low interference threshold being a lower threshold than the high interference threshold.
5. The method of claim 1 , wherein the zone overload information is received by a base station associated with the serving cell.
6. The method of claim 1 comprising the additional steps of:
prior to receiving the zone overload information, receiving an overload channel list indicating overload channels for one or more neighbor cells; and
monitoring one or more overload channels indicated in the overload channel list.
7. The method of claim 1 , wherein the step of adjusting the transmit power parameter comprises the step of:
decreasing a transmit power parameter associated with a sub-carrier assigned to the mobile telephone if the received zone overload information indicates that the assigned sub-carrier corresponds to an overloaded zone.
8. The method of claim 1 , wherein the step of adjusting the transmit power parameter comprises the step of:
increasing a transmit power parameter associated with a sub-carrier assigned to the mobile telephone if the received zone overload information indicates that the assigned sub-carrier corresponds to a non-overloaded zone.
9. The method of claim 1 , wherein the transmit power parameter is a constraint associated with a maximum allowable transmit power.
10. The method of claim 1 , wherein the transmit power parameter is adjusted based on relative received pilot powers of the serving cell and the neighbor cell.
11. A method of controlling transmit power in a wireless communication system comprising the steps of:
determining whether a first low interference zone of a first cell is interference overloaded;
determining whether a first high interference zone of the first cell is interference overloaded; and
transmitting a first zone overload information indicating whether the first low interference zone or first high interference zone is interference overloaded.
12. The method of claim 11 , wherein the first low interference zone is determined to be interference overloaded if interference measurements associated with the first low interference zone is above a first low interference threshold, the first high interference zone is determined to be interference overloaded if interference measurements associated with the first high interference zone is above a first high interference threshold, the first low interference threshold be lower relative to the first high interference threshold.
13. The method of claim 11 comprising the additional steps of:
determining whether a second low interference zone of a second cell is interference overloaded, wherein second cell is adjacent to the first cell, the second low interference zone is associated with a different set of sub-carriers relative to the first low interference zone; and
determining whether a second high interference zone of the second cell is interference overloaded; and
transmitting a second zone overload information indicating whether the second low interference zone or second high interference zone is interference overloaded.
14. The method of claim 12 comprising the additional step
receiving the first and second zone overload information; and
adjusting a transmit power parameter of a mobile station in a third cell based on at least one of the received first and second zone overload information.
15. A wireless communication system comprising:
a first base station operable to determine whether an associated first low interference zone is interference overloaded and whether an associated first high interference zone is interference overloaded and to transmit first zone overload information indicating whether the first low interference zone or first high interference zone is interference overloaded.
16. The wireless communication system of claim 15 further comprising:
a second base station operable to receive the first zone overload information and to adjust a transmit parameter of a mobile station based on the received first zone overload information.
17. The wireless communication system of claim 15 further comprising:
a mobile station operable to receive the first zone overload information and to adjust a transmit parameter of the mobile station based on the received first zone overload information.
18. The wireless communication system of claim 17 , wherein the mobile station decreases a transmit power parameter associated with a sub-carrier assigned to the mobile telephone if the received first zone overload information indicates that the assigned sub-carrier corresponds to an overloaded zone.
19. The wireless communication system of claim 17 , wherein the mobile station increases a transmit power parameter associated with a sub-carrier assigned to the mobile telephone if the received first zone overload information indicates that the assigned sub-carrier corresponds to a non-overloaded zone.