Method for data communications using multi-beamforming in mobile communication system and apparatus therefor

1. An operation method of a base station in a mobile communication system, the operation method comprising:

performing a beam management procedure for selecting at least one beam and transmitting a different channel state information reference signal (CSI-RS) for each beam to a terminal through the at least one beam;

receiving beam quality information for the at least one beam from the terminal;

transmitting at least one CSI-RS for CSI acquisition configured according a beam management update procedure based on the beam quality information to the terminal through the at least one beam; and

receiving channel state information (CSI) based on the CSI-RS for CSI acquisition from the terminal.

2. The operation method according to claim 1 , further comprising performing scheduling for transmission of data to the terminal based on the CSI.

3. The operation method according to claim 1 , wherein at least one of a signal pattern of the at least one CSI-RS, a number of resources for the at least one CSI-RS, and information on at least one antenna port per CSI-RS resource is configured through higher layer control information of the base station.

4. The operation method according to claim 1 , wherein each of the at least one beam is a cell-specific beam or a user equipment (UE) specific beam.

5. The operation method according to claim 1 , wherein the beam quality information includes at least one of a CSI-RS resource indicator (CRI), a precoding matrix indicator (PMI), a rank indicator (RI), a channel quality indicator (CQI), or a reference signal received power (RSRP) for the at least one CSI-RS.

6. The operation method according to claim 1 , wherein a number of antenna ports used for a CSI-RS resource used in the beam management procedure is equal to or greater than a number of antenna ports used for a CSI-RS resource used for the CSI acquisition.

7. The operation method according to claim 1 , further comprising transmitting a spatial quasi-co-location (QCL) information to the terminal, when the CSI-RS of the beam management procedure and the CSI-RS for CSI acquisition have a same spatial characteristic.

8. The operation method according to claim 1 , wherein the performing of the beam management procedure and the receiving of the CSI are performed in one of a periodical manner, a non-periodical manner, or a semi-persistent manner.

9. The operation method according to claim 8 , wherein the receiving of the CSI comprises a first CSI acquisition procedure and a second CSI acquisition procedure, each of which is performed according to a same cycle or according to a different cycle.

10. The operation method according to claim 1 , wherein the CSI includes at least one of a rank indicator (RI), a precoder matrix indicator (PMI), or a channel-quality indicator (CQI).

11. An operation method of a terminal in a mobile communication system, the operation method comprising:

receiving at least one channel state information reference signal (CSI-RS) from a base station through at least one beam selected through a beam management procedure of the base station;

transmitting to the base station beam quality information based on the at least one CSI-RS received from the base station;

receiving from the base station at least one CSI-RS for CSI acquisition configured based on the beam quality information; and

transmitting channel state information (CSI) based on the at least one CSI-RS for CSI acquisition to the base station;

wherein a number of antenna ports used by a CSI-RS resource used in the beam management procedure is equal to or greater than a number of antenna ports used by a CSI-RS resource used for the CSI acquisition.

12. The operation method according to claim 11 , wherein at least one of a signal pattern of the at least one CSI-RS, a number of resources for the at least one CSI-RS, and information on at least one antenna port per CSI-RS resource is configured through higher layer control information of the base station.

13. The operation method according to claim 11 , wherein the beam quality information includes at least one of a CSI-RS resource indicator (CRI), a precoding matrix indicator (PMI), a rank indicator (RI), a channel quality indicator (CQI), or a reference signal received power (RSRP) for the at least one CSI-RS.

14. The operation method according to claim 11 , wherein the CSI includes at least one of a rank indicator (RI), a precoder matrix indicator (PMI), or a channel-quality indicator (CQI).

15. A terminal in a mobile communication system, the terminal comprising at least one processor, a memory storing at least one instruction executable by the at least one processor, and a transceiver controlled by the at least one processor, wherein the at least one instruction is configured to, when executed by the at least one processor:

receive, by using the transceiver, at least one channel state information reference signal (CSI-RS) from a base station through at least one beam selected through a beam management procedure of the base station;

transmit, by using the transceiver, to the base station beam quality information based on the at least one CSI-RS received from the base station;

receive, by using the transceiver, from the base station at least one CSI-RS for CSI acquisition configured based on the beam quality information; and

transmit, by using the transceiver, channel state information (CSI) based on the at least one CSI-RS for CSI acquisition to the base station;

wherein a number of antenna ports used for a CSI-RS resource used in the beam management procedure is equal to or greater than a number of antenna ports used for a CSI-RS resource used for the CSI acquisition.

16. The terminal according to claim 15 , wherein at least one of a signal pattern of the at least one CSI-RS, a number of resources for the at least one CSI-RS, and information on at least one antenna port per CSI-RS resource is configured through higher layer control information of the base station.

17. The terminal according to claim 15 , wherein the beam quality information includes at least one of a CSI-RS resource indicator (CRI), a precoding matrix indicator (PMI), a rank indicator (RI), a channel quality indicator (CQI), or a reference signal received power (RSRP) for the at least one CSI-RS.

18. The terminal according to claim 15 , wherein the CSI includes at least one of a rank indicator (RI), a precoder matrix indicator (PMI), or a channel-quality indicator (CQI).