In RAN1#98bis, in addition to DL MI

In RAN1#98bis, in addition to DL MIMO layer adaptation, there was a suggestion to support adaptation of maximum number of UL MIMO layers [3]. However, UE’s power saving gain achievable by UL MIMO layer adaptation was not intensively discussed during the UE power saving study item phase and no recommendation was made on that as a conclusion of the study item. Moreover, in many cases, UE may be able to turn on/off its transmit antenna power considering gNB’s UL scheduling when there is enough time between DCI decoding and the UL transmission timing, depending on the UE’s RF implementation. Therefore, we don’t see an urgent reason to introduce dynamic UL MIMO layer adaptation in this late stage of Rel-16 specification.