Method for transmitting and receiving channel state information in wireless communication system and apparatus therefor
In an aspect of the present invention, a method for reporting channel state information (CSI) of a UE in a wireless communication system includes: receiving, from an eNB, CSI-RS resource information related to a CSI-RS resource to which a channel state information-reference signal (CSI-RS) is mapped; receiving the CSI-RS transmitted through one or more antenna ports from the eNB based on the received CSI-RS resource information; and reporting CSI generated based on the received CSI-RS to the eNB, in which the CSI-RS resource is configured by aggregating a plurality of CSI-RS resources, and the aggregated CSI-RS resources are respectively positioned in different subframes on a time axis or in different resource blocks on a frequency axis.
1. A method for reporting channel state information (CSI) of a user equipment (UE) in a wireless communication system, comprising:
receiving, from an eNB, CSI-RS (CSI-reference signal) resource information related to a plurality of CSI-RS resources corresponding to a 24-port CSI-RS resource comprising an aggregation of first to third 8-port CSI-RS resources,
the first to third 8-port CSI-RS resources being located in third and fourth OFDM symbol regions of a second slot in a single subframe on the time axis,
the first 8-port CSI-RS resource being located in first to fourth subcarrier regions on the frequency axis,
the second 8-port CSI-RS resource is located in fifth to eighth subcarrier regions on the frequency axis, and
the third 8-port CSI-RS resource is located in ninth to twelfth subcarrier regions on the frequency axis;
receiving, from the eNB, a plurality of CSI-RSs mapped to the plurality of aggregated first to third 8-port CSI-RS resources, based on the received CSI-RS resource information; and
reporting, to the eNB, CSI generated based on the plurality of CSI-RSs.
2. The method of claim 1 , wherein at least one of the aggregated CSI-RS resources corresponds to a composite CSI-RS resource configured by aggregating a plurality of legacy CSI-RS resources.
3. The method of claim 2 , wherein the plurality of legacy CSI-RS resources constituting the composite CSI-RS resource is limited to CSI-RS resources of the same number of ports.
4. The method of claim 1 , wherein the CSI-RS resource is limited such that the CSI-RS is configured by aggregating CSI-RS resources of a predefined number of ports.
5. The method of claim 1 , wherein the different subframes in which the aggregated CSI-RS resources are positioned have different CSI-RS subframe offsets.
6. The method of claim 5 further comprising:
based on the aggregated CSI-RS resources being respectively positioned in the different subframes having a spacing of a predetermined number of subframes there between, receiving, from the eNB, information related to the spacing of the predetermined number of subframes through radio resource control (RRC) signaling.
7. The method of claim 5 , wherein, based on the aggregated CSI-RS resources being respectively positioned in different subframes on the time axis, the aggregated CSI-RS resources are mapped to the same subcarriers in the different subframes.
8. The method of claim 1 further comprising:
based on the aggregated CSI-RS resources being respectively positioned in different resource blocks having a spacing of a predetermined number of resources blocks there between, receiving, from the eNB, information related to the spacing of the predetermined number of resource blocks through RRC signaling.
9. The method of claim 1 , wherein a transmission periodicity of different resource blocks in which the aggregated CSI-RS resources are positioned is set to be the same for each of the aggregated CSI-RS resources, and a resource block offset of the different resource blocks is set differently for each of the aggregated CSI-RS resources.
10. The method of claim 9 , wherein the transmission periodicity and the resource block offset are joint-encoded and transmitted to the UE.
11. The method of claim 1 , wherein the plurality of CSI-RSs are applied with code division multiplexing (CDM) in which a number of orthogonal weight vectors is 6, 8, 12, 16 or 20 according to the number of ports of each of the plurality of CSI-RS resources aggregated into the plurality of CSI-RS resources to which the plurality of CSI-RSs are mapped.
12. The method of claim 1 , wherein CSI-RS mapped to each of the first to third 8-port CSI resources is applied to code division multiplexing (CDM) in which a number of orthogonal weight vectors is 8.
13. A user equipment (UE) transmitting channel state information (CSI) in a wireless communication system, comprising:
a transmitter and a receiver; and
a processor for controlling the transmitter and receiver,
wherein the processor is configured:
to receive, from an eNB, CSI-RS (CSI-reference signal) resource information related to a plurality of CSI-RS resources corresponding to a 24-port CSI-RS resource comprising an aggregation of first to third 8-port CSI-RS resources
the first to third 8-port CSI-RS resources being located in third and fourth OFDM symbol regions of a second slot in a single subframe on the time axis,
the first 8-port CSI-RS resource being located in first to fourth subcarrier regions on the frequency axis,
the second 8-port CSI-RS resource is located in fifth to eighth subcarrier regions on the frequency axis, and
the third 8-port CSI-RS resource is located in ninth to twelfth subcarrier regions on the frequency axis;
to receive, from the eNB, a plurality of CSI-RSs mapped to the plurality of aggregated first to third 8-port CSI-RS resources, based on the received CSI-RS resource information; and
to report, to the eNB, CSI generated based on the plurality of CSI-RSs.