Methods and procedures for channel measurements and reporting mechanisms

A wireless transmit/receive unit (WTRU) configured to operate on a frequency band, the WTRU comprising:

• a processor;
• and
• a transceiver operatively coupled to the processor;
• wherein:
• the transceiver is configured to receive configuration information indicating a plurality of sets of resource elements (REs), wherein each of the plurality of sets of REs is associated with a Channel-State-Information Reference Signal (CSI-RS) configuration;
• the transceiver is configured to receive a request in Downlink Control Information (DCI), in a first time unit, to receive at least one CSI-RS, in at least one set of the plurality of sets of REs, in the first time unit, to perform a measurement and to report the measurement, wherein the request indicates the at least one set of the plurality of sets of REs;
• the transceiver is configured to receive the at least one CSI-RS, in the at least one set of the plurality of sets of REs, in the first time unit, according to the request;
• the transceiver and the processor are configured to perform the measurement of the at least one CSI-RS;
• and
• the transceiver and the processor are configured to transmit, in at least one of the first time unit and a second time unit, a measurement report based on the performed measurement.

A base station comprising:

• a processor;
• and
• a transceiver operatively coupled to the processor;
• wherein:
• the processor and the transceiver are configured to transmit, to a wireless transmit/receive unit (WTRU), configuration information indicating a plurality of sets of resource elements (REs), wherein each of the plurality of sets of REs is associated with a Channel-State-Information Reference Signal (CSI-RS) configuration;
• the processor is configured to select at least one set of the plurality of sets of REs;
• the processor and the transceiver are configured to transmit, to the WTRU, a request in Downlink Control Information (DCI), in a first time unit, to receive at least one CSI-RS, in the selected at least one set of the plurality of sets of REs, in the first time unit, to perform a measurement and to report the measurement, wherein the request indicates the at least one set of the plurality of sets of REs;
• the processor and the transceiver are configured to transmit, to the WTRU, the at least one CSI-RS, in the selected at least one set of the plurality of sets of REs, in the first time unit, according to the request;
• and
• the transceiver configured to receive, from the WTRU, in at least one of the first time unit and a second time unit, a measurement report responsive to the request.