Uplink multiple-input multiple-output with different antenna groups

An apparatus for wireless communication at a user equipment (UE), the apparatus comprising:

• a processor;
• memory coupled with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the apparatus to:
• receive, from a base station, an indication of at least one active antenna port group of a plurality of antenna port groups, wherein the plurality of antenna port groups comprises a first antenna port group and a second antenna port group, wherein the indication comprising a first indication indicates that the first antenna port group is the at least one active antenna port group, and wherein the indication comprising a second indication indicates that the second antenna port group is the at least one active antenna port group;
• and
• map one or more layers of an uplink message to the at least one active antenna port group based at least in part on the indication of the at least one active antenna port group.

An apparatus for wireless communication at a base station, the apparatus comprising:

• a processor;
• memory coupled with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the apparatus to:
• transmit, to a user equipment (UE), an indication of at least one active antenna port group of a plurality of antenna port groups the plurality of antenna port groups comprises a first antenna port group and a second port antenna port group, wherein the indication comprising a first indication indicates that the first antenna port group is the at least one active antenna port group, and wherein the indication comprising a second indication indicates that the second antenna port group is the at least one active antenna port group;
• and
• receive, from the UE, one or more layers of an uplink message mapped to the at least one active antenna port group based at least in part on the indication of the at least one active antenna port group.