Method and apparatus for performing interference coordination in wireless communication system

1. A method for performing interference coordination in a wireless communication system, by a user equipment (UE), the method comprising:

transmitting, by the UE, measurement results on neighboring cells, to a serving cell,

wherein the measurement results on the neighboring cells are shared with each of the neighboring cells, and

wherein the number of overlapped UEs between the serving cell and each of the neighboring cells is calculated, based on the shared measurement results on the neighboring cells;

receiving, by the UE, information on cell grouping of the neighboring cells,

wherein the cell grouping is performed between the serving cell and a neighboring cell, based on the number of overlapped UEs between the serving cell and the neighboring cell;

receiving a time division duplex (TDD) reference configuration to minimize conflicts between cell groups and a shift value to be selected in subframes which are changed by the cell grouping, from the serving cell;

acquiring different TDD configurations by using the TDD reference configuration and the shift value for the cell groups; and

receiving a signal to be applied with at least one of a certain sub-band, a subframe shift, or an orthogonal frequency division multiplexing (OFDM) symbol shift according to a cell group which is defined by the cell grouping.

2. The method of claim 1 , wherein the information on the cell grouping includes resource mapping information including a sub-band and a subframe in which a synchronization signal and a reference signal are transmitted according to the cell group, and the sub-band and the subframe are changed by the cell group.

3. The method of claim 2 , wherein the cell grouping is determined by at least one of a backhaul quality between cells, a discovery signal strength, a frequency carrier, a discovery signal via air interface, a cell identification (ID), a cell coverage, a TDD configuration, or a frequency division duplex (FDD) configuration.

4. The method of claim 2 , wherein the information includes a list of cell identifications (IDs) having a cell-specific reference signal (CRS) port or a multicast-broadcast single-frequency network (MBSFN) configuration which is configured to the UE.

5. The method of claim 1 , further comprising:

controlling a power of an uplink transmission at predetermined subframes by using the information on the cell grouping to minimise conflicts between the cell groups.

6. The method of claim 1 , further comprising:

exchanging the information between small cells of the neighboring cells,

wherein the information includes at least one of a load indication to indicate an uplink interference overload indication per subframe, a high interference indication per subframe or per a hybrid automatic repeat request (HARQ) process, information of a relative lower transmission power subframe (RLTPS), and a radio resource status.

7. The method of claim 1 , further comprising:

receiving different TDD configurations of the neighboring cells,

wherein each TDD configuration each includes at least one of a set of hybrid automatic repeat request (HARQ) processes to use with a maximum power or a lower power, a subframe configuration as a candidate HARQ process, or a subframe set configuration to indicate a high interference indication per subframe or per a HARQ process.

8. The method of claim 1 , further comprising;

receiving measurement configurations according to the information on the cell grouping,

wherein a measurement based on the measurement configurations includes at least one of a Reference Signal Received Power (RSRP), a Reference Signal Received Quality (RSRQ), or a Received Signal Strength Indicator (RSSI).

9. A wireless device for performing interference coordination in a wireless communication system, the wireless device comprising:

a transceiver configured to transmit and receive a radio signal; and

a processor operatively coupled to the transceiver,

wherein the processor is configured to:

control the transceiver to transmit measurement results on neighboring cells, to a serving cell,

wherein the measurement results on the neighboring cells are shared with each of the neighboring cells, and

wherein the number of overlapped UEs between the serving cell and each of the neighboring cells is calculated, based on the shared measurement results on the neighboring cells,

control the transceiver to receive information on cell grouping of the neighboring cells,

wherein the cell grouping is performed between the serving cell and a neighboring cell, based on the number of overlapped UEs between the serving cell and the neighboring cell,

control the transceiver to receive a time division duplex (TDD) reference configuration to minimize conflicts between cell groups and a shift value to be selected in subframes which are changed by the cell grouping, from the serving cell,

acquiring different TDD configurations by using the TDD reference configuration and the shift value for the cell groups, and

control the transceiver to receive a signal to be applied with at least one of a certain sub-band, a subframe shift, or an orthogonal frequency division multiplexing (OFDM) symbol shift according to a cell group which is defined by the cell grouping.

10. The wireless device of claim 9 , wherein the processor is further configured to:

control a power of an uplink transmission at predetermined subframes by using the information on the cell grouping to minimize conflicts between the cell groups.

11. The wireless device of claim 9 , wherein the processor is further configured to receive different TDD configurations of the neighboring cells, and

wherein each TDD configuration includes at least one of a set of hybrid automatic repeat request (HARQ) processes to use with a maximum power or a lower power, a subframe configuration as a candidate HARQ process, or a subframe set configuration to indicate a high interference indication per subframe or per a HARQ process.

12. The wireless device of claim 9 , wherein the processor is further configured to receive measurement configurations according to the information on the cell grouping, and

wherein a measurement based on the measurement configurations includes at least one of a Reference Signal Received Power (RSRP), a Reference Signal Received Quality (RSRQ), or a Received Signal Strength Indicator (RSSI).

13. The wireless device of claim 9 , wherein the information on the cell grouping includes resource mapping information including a sub-band and a subframe in which a synchronization signal and a reference signal are transmitted according to the cell group, and the sub-band and the subframe are changed by the cell group, and

wherein the cell grouping is determined by at least one of a backhaul quality between cells, a discovery signal strength, a frequency carrier, a discovery signal via air interface, a cell identification (ID), a cell coverage, a TDD configuration, or a frequency division duplex (FDD) configuration.

14. The wireless device of claim 9 , wherein the processor is further configured to exchange the information between small cells of the neighboring cells, and

wherein the information includes at least one of a load indication to indicate an uplink interference overload indication per subframe, a high interference indication per subframe or per a hybrid automatic repeat request (HARQ) process, information of a relative lower transmission power subframe (RLTPS), and a radio resource status.