Method and apparatus for enabling uplink MIMO

A base station (BS) comprising:

• a processor configured to:
• generate, for a user equipment (UE), configuration information that includes a selected uplink (UL) transmission scheme and at least one reference signal (RS) resource;
• and
• a transceiver operably connected to the processor, the transceiver configured to:
• transmit, to the UE, the configuration information;
• and
• transmit, to the UE, an UL-related downlink control information (DCI),
• wherein the selected UL transmission scheme is one of an UL transmission without precoding matrix indicator (PMI) and an UL transmission with PMI,
• wherein the at least one RS resource corresponds to a channel state information RS (CSI-RS) resource, and
• wherein the CSI-RS resource is used for an UL precoder calculation when the selected UL transmission scheme corresponds to the UL transmission without the PMI in the UL-related DCI.

A method for operating a user equipment (UE), the method comprising:

• receiving, from a base station (BS), configuration information that includes a selected uplink (UL) transmission scheme and at least one reference signal (RS) resource for precoder calculation;
• decoding the configuration information;
• and
• determining the selected UL transmission scheme and the at least one RS resource for an UL precoder calculation,
• wherein the selected UL transmission scheme is one of an UL transmission without precoding matrix indicator (PMI) and an UL transmission with PMI,
• wherein the at least one RS resource corresponds to a channel state information RS (CSI-RS) resource, and
• wherein the CSI-RS resource is used for the UL precoder calculation based on the selected UL transmission scheme corresponding to the UL transmission without the PMI in an UL-related downlink control information (DCI).