Terminal and wireless communication method for receiving a demodulation reference signal

A base station, comprising:

• a transmitter that transmits, via radio resource control (RRC) signaling, information of a configuration indicative of a group of resources among a plurality of groups of resources to which a demodulation reference signal is mapped, and transmits downlink control information (DCI) including an index;
• and
• a processor that maps a demodulation reference signal to a resource for a physical downlink shared channel (PDSCH) among the group of resources based on the index and the group of resources,
• wherein a maximum number of symbols to which the demodulation reference signal is mapped to the resource for the PDSCH is configured by the RRC signaling,
• wherein an additional demodulation reference signal is further mapped in the PDSCH,
• wherein a position of the additional demodulation reference signal in the PDSCH is configured by the RRC signaling,
• wherein the processor controls transmission of the additional demodulation reference signal in the PDSCH,
• wherein the demodulation reference signal is mapped to no physical resource where the demodulation reference signal overlaps with another reference signal in the PDSCH,
• wherein a mapping position of the demodulation reference signal is determined based on one of only two configuration types based on the information of the configuration,
• wherein each of the two configuration types includes at least two mapping patterns, and
• wherein a number of symbols to which the demodulation reference signal is mapped in one of the at least two mapping patterns is different in time domain from a number of symbols to which the demodulation reference signal is mapped in another one of the at least two mapping patterns.

A wireless communication system comprising a base station and a terminal,

• wherein the base station comprises:
• a transmitter that transmits, via radio resource control (RRC) signaling, information of a configuration indicative of a group of resources among a plurality of groups of resources to which a demodulation reference signal is mapped, and transmits downlink control information (DCI) including an index;
• and
• a first processor that maps a demodulation reference signal to a resource for a physical downlink shared channel (PDSCH) among the group of resources based on the index and the group of resources,
• wherein the terminal comprises:
• a receiver that receives, via the RRC signaling, the information of the configuration indicative of the group of resources among the plurality of groups of resources to which the demodulation reference signal is mapped and the DCI including the index;
• and
• a second processor that controls reception of the demodulation reference signal in the PDSCH using the resource among the group of resources based on the index and the group of resources, and
• wherein a maximum number of symbols to which the demodulation reference signal is mapped to a resource for the PDSCH is configured by the RRC signaling,
• wherein an additional demodulation reference signal is further mapped in the PDSCH,
• wherein a position of the additional demodulation reference signal in the PDSCH is configured by the RRC signaling,
• wherein the second processor controls reception of the additional demodulation reference signal in the PDSCH,
• wherein the demodulation reference signal is mapped to no physical resource where the demodulation reference signal overlaps with another reference signal in the PDSCH,
• wherein a mapping position of the demodulation reference signal is determined based on one of only two configuration types based on the information of the configuration,
• wherein each of the two configuration types includes at least two mapping patterns, and
• wherein a number of symbols to which the demodulation reference signal is mapped in one of the at least two mapping patterns is different in time domain from a number of symbols to which the demodulation reference signal is mapped in another one of the at least two mapping patterns.