Method of transmitting and receiving downlink signal in wireless communication system and apparatus therefor

A user equipment (UE) for reporting channel state information (CSI) in a wireless communication system, the method comprising:

• a memory;
• a transceiver;
• and
• a processor operatively connected to the memory and the transceiver, the processor for:
• receiving, from a base station (BS) via radio resource control (RRC) signaling, information on plural aperiodic channel state information-reference signal (CSI-RS) measurement configurations,
• receiving, from the BS in a first time interval, downlink control information (DCI) comprising a field having a bit length and value corresponding to one of the plural aperiodic CSI-RS measurement configurations,
• receiving a aperiodic CSI-RS in a second time interval according to the one of the plural aperiodic CSI-RS measurement configurations, wherein the second time interval is determined based on the first time interval,
• performing an aperiodic CSI-RS measurement on the aperiodic CSI-RS, and
• reporting CSI based on the aperiodic CSI-RS measurement,
• wherein first resource elements (REs) for the aperiodic CSI-RS are different from second REs for a physical downlink shared channel (PDSCH).

An apparatus, comprising:

• a memory;
• and
• a processor coupled to the memory, the processor for:
• receiving, from a base station (BS) via radio resource control (RRC) signaling, information on plural aperiodic channel state information-reference signal (CSI-RS) measurement configurations,
• receiving, from the BS in a first time interval, downlink control information (DCI) comprising a field having a bit length and value corresponding to one of the plural aperiodic CSI-RS measurement configurations,
• receiving a aperiodic CSI-RS in a second time interval according to the one of the plural aperiodic CSI-RS measurement configurations, wherein the second time interval is determined based on the first time interval,
• performing an aperiodic CSI-RS measurement on the aperiodic CSI-RS, and
• reporting CSI based on the aperiodic CSI-RS measurement,
• wherein first resource elements (REs) for the aperiodic CSI-RS are different from second REs for a physical downlink shared channel (PDSCH).