Patent ID: 11894925
Assignee: NTT DOCOMO, INC.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 4:
5. A system comprising a base station and a terminal among a terminal group comprising a plurality of terminals which is grouped in a cell, wherein
the terminal comprises:
a receiver that receives configuration information using radio resource control (RRC) signaling, an aperiodic Channel State Information Reference Signal (CSI-RS) to be used for the terminal group, and a trigger signal using a downlink control information (DCI) field which indicates the aperiodic CSI-RS in a frequency domain in a bandwidth that is the same as a bandwidth for a time and frequency resource that is used for data transmission to the terminal; and
a processor,
wherein if the trigger signal is received then the processor, based on the received configuration information and the received trigger signal, specifies a time and frequency resource for the aperiodic CSI-RS from a plurality of time and frequency resources, and
the processor performs rate matching related to the specified time and frequency resource based on the trigger signal, and
if the trigger signal is not received and the configuration information is received, the processor determines not to use the aperiodic CSI-RS, and the base station comprises:
a transmitter that transmits the configuration information using the RRC signaling, the aperiodic CSI-RS to be used for the terminal group, and the DCI field.