Method for configuring and allocating forward channel in orthogonal frequency division multiple access frequency division duplex system

1. In a method for respective base stations of a plurality of cells to configure forward channels transmitted to a mobile station in an FDD (frequency division duplex) based mobile communication system, a forward channel configuring method comprising:

(a) classifying the cells into a specific number of interference patterns based on location relations of the respective cells;

(b) preventing the respective base stations of the cells having different classified patterns to sequentially transmit control information to the mobile station during different defined periods within a period of the forward channel, and allowing the respective base stations of the cells having the same classified patterns to concurrently transmit control information to the mobile station exclusively during one of the defined periods; and

(c) allowing the respective base stations to transmit traffic data to the mobile station irrespective of the classified patterns when the control information is transmitted in (b), wherein (a) comprises classifying the cells, which have less inter-cell interference since the cells are not adjacent, as those having the same pattern.

2. The forward channel configuring method of claim 1 , wherein (a) comprises classifying cells, which are symmetric with respect to a specific cell from among the adjacent cells, as the same pattern with reference to the specific cell from the cells.

3. The forward channel configuring method of claim 1 , wherein the period of the forward channel in (b) includes control information with respect to a number of patterns classified in (a).

4. The forward channel configuring method of claim 3 , wherein the period of the forward channel includes a time for transmitting traffic data by the number of patterns classified in (a).

5. The forward channel configuring method of claim 4 , wherein the control information and the traffic data are alternately transmitted by the number of classified patterns.

6. The forward channel configuring method of claim 1 , wherein when the mobile station attempts a call to the base station of the cell to which the mobile station belongs to for the first time, the control information through which the base station responds to the mobile station which attempts the call for the first time is transmitted during an interval in which the base station transmits traffic data to the mobile station which attempts the call for the first time.

7. In a method for allocating forward channels to a mobile station located in a cell in an FDD (frequency division duplex) based mobile communication system, the method comprising:

(a) finding location information and power information on the mobile station, and determining whether the mobile station is provided in a handoff region located in an inter-cell region adjacent to the mobile station;

(b) allocating a service-possible subcarrier specific to the cell as a subcarrier usable by the mobile station when the mobile station is found to be provided in a handoff region in (a); and

(c) allocating the service-possible subcarrier as a subcarrier usable by the mobile station by using information having different SIR (signal to interference ratio) values for the respective subcarriers to be allocated when the mobile station is found to be provided in a non-handoff region located in the inter-cell region adjacent to the mobile station in (a), wherein collisions generated in the inter-cell adjacent region are prevented.

8. The method of claim 7 , wherein the service-possible subcarrier specific to the cell in (b) is established so that classified patterns may not be repeated with service-possible subcarriers specific to different cells when the cells are classified as a predetermined number of patterns based on the respective location relations of the cells included in the mobile communication system.

9. The method of claim 8 , wherein the service-possible subcarrier specific to the cell is established to correspond to the service-possible subcarriers specific to the cells having the same classified pattern.

10. The method of claim 7 , wherein the subcarriers except the service-possible subcarrier specific to the cell in (b) are punctured by the mobile stations in the handoff region within the cell.

11. The method of claim 7 , wherein the service-possible subcarrier specific to the cell is modified according to a transmission frame of the traffic data.

12. The method of claim 7 , wherein (c) comprises:

measuring an SIR value for each subcarrier to be allocated; and

allocating the subcarrier, which has the measured SIR value greater than a specific threshold value, as a subcarrier usable by the mobile station.

13. The method of claim 8 , wherein the cells which have less inter-cell interference because the cells are not adjacent are classified as those having the same pattern.

14. The method of claim 8 , wherein the cells which are symmetric with respect to the specific cell from among the adjacent cells with reference to the specific central cell from among the cells are classified as those having the same pattern.

15. In a method for respective base stations of a plurality of cells to configure forward channels transmitted to a mobile station in an FDD (frequency division duplex) based mobile communication system, a recording medium for storing a program for realizing functions comprising:

(a) classifying the cells into a specific number of interference patterns based on location relations of the respective cells;

(b) preventing the respective base stations of the cells having different classified patterns to sequentially transmit control information to the mobile station during different defined periods within a period of the forward channel, and the respective base stations of the cells having the same classified patterns to concurrently transmit control information to the mobile station exclusively during one of the defined periods; and

(c) allowing the respective base stations to transmit traffic data to the mobile station irrespective of the classified patterns when the control information is transmitted in (b).

16. In a method for allocating forward channels to a mobile station located in a cell in an FDD (frequency division duplex) based mobile communication system, a recording medium for storing a program for realizing functions comprising:

(a) finding location information and power information on the mobile station, and determining whether the mobile station is provided in a handoff region located in an inter-cell region adjacent to the mobile station;

(b) allocating a service-possible subcarrier specific to the cell as a subcarrier usable by the mobile station when the mobile station is found to be provided in the handoff region in (a); and

(c) allocating the service-possible subcarrier as a subcarrier usable by the mobile station by using information having different SIR (signal to interference ratio) values for the respective subcarriers to be allocated when the mobile station is found to be provided in a non-handoff region located in the inter-cell region adjacent to the mobile station in (a), wherein collisions generated in the inter-cell adjacent region are prevented.