Apparatus and method

1. An apparatus comprising:

a processing circuit that feeds back a channel quality indicator (CQI) of a serving base station, which is calculated on a basis of

an estimated received power of a desired data signal estimated from a result of measuring a first reference signal received from the serving base station,

an estimated received power of an interference data signal estimated from a result of measuring a second reference signal received from a neighbor base station, and

information related to a power difference between the first reference signal and a data signal of the neighbor base station,

to the serving base station.

2. The apparatus according to claim 1 ,

wherein the information related to the difference includes information related to an assumed ratio of an energy per resource element (EPRE) of the data signal with respect to an EPRE of the second reference signal of the neighbor base station.

3. The apparatus according to claim 2 ,

wherein the information related to the difference includes information that indicates the ratio corresponding to at least a part of an interference measurement resource (IMR), and

the second reference signal of the neighbor base station is received by the IMR corresponding to the ratio.

4. The apparatus according to claim 3 ,

wherein one or more reference signals are received by the IMR.

5. The apparatus according to claim 1 ,

wherein the information related to the difference includes information that indicates a base station corresponding to each IMR, and

the second reference signal of the neighbor base station is received by a different IMR for each base station.

6. The apparatus according to claim 1 ,

wherein the information related to the difference includes information that indicates restriction of a transmission schedule of the data signal in the neighbor base station in a predetermined period of time in future.

7. The apparatus according to claim 6 ,

wherein the information that indicates the restriction of the transmission schedule includes information that indicates whether or not each sub-band is used to transmit the data signal.

8. The apparatus according to claim 6 ,

wherein the information that indicates the restriction of the transmission schedule includes information that indicates whether or not each beam is used to transmit the data signal.

9. The apparatus according to claim 6 ,

wherein the information related to the difference includes information that indicates the restriction of the transmission schedule corresponding to each IMR, and

the second reference signal of the neighbor base station is received by an IMR corresponding to the restriction of the transmission schedule of the neighbor base station.

10. The apparatus according to claim 1 ,

wherein the first and second reference signals are channel state information reference signals (CSI-RS).

11. The apparatus according to claim 1 ,

wherein the data signal is a signal that is transmitted through a physical downlink shared channel (PDSCH).

12. The apparatus according to claim 1 ,

wherein the first and second reference signals are subjected to beamforming.

13. An apparatus comprising:

a processing circuit that provides a notification of information related to a power difference between a first reference signal and a data signal of a neighbor base station to a terminal apparatus under the control of the apparatus and receives feedback of a CQI that is calculated on a basis of

an estimated received power of a desired data signal estimated from a result of measuring the first reference signal that is received from a serving base station,

an estimated received power of an interference data signal estimated from a result of measuring a second reference signal received from the neighbor base station, and

information related to the difference from the terminal apparatus.

14. The apparatus according to claim 13 ,

wherein the processing circuit provides a notification of information that indicates an assumed ratio of an EPRE of the data signal with respect to an EPRE of the reference signal, which corresponds to each IMR, to the neighbor base station.

15. The apparatus according to claim 14 ,

wherein the processing circuit provides a notification of information that indicates a position of the IMR to the neighbor base station.

16. The apparatus according to claim 13 ,

wherein the processing circuit acquires information related to a transmission schedule of the second reference signal from the neighbor base station.

17. The apparatus according to claim 16 ,

wherein the processing circuit acquires information that indicates an assumed ratio of the EPRE of the data signal with respect to the EPRE of the second reference signal of the neighbor base station.

18. The apparatus according to claim 13 ,

wherein the processing circuit controls whether or not to provide the notification of the information related to the difference to the terminal apparatus.

19. The apparatus according to claim 13 ,

wherein the processing circuit acquires information that indicates restriction of a transmission schedule of the data signal in the neighbor base station in a predetermined period of time in future from the neighbor base station.

20. A method comprising:

feeding back a channel quality indicator (CQI) of a serving base station, which is calculated on a basis of

an estimated received power of a desired data signal estimated from a result of measuring a first reference signal received from the serving base station,

an estimated received power of an interference data signal estimated from a result of measuring a second reference signal received from a neighbor base station, and

information related to a power difference between the first reference signal and a data signal of the neighbor base station,

to the serving base station.