ct a group g, with an accompanying basis E and schedule up to M code words of independent data to different UEs, depending on the scheduler design. The following are the main features of PU2RC: Multiple sets of unitary precoding are predetermined and the degree of free- dom in the unitary precoding selection provides multiuser diversity gain in the space domain. © 2009 by Taylor & Francis Group, LLC Long Term Evolution: 3GPP LTE Radio and Cellular Technology PU2RC with partial feedback: UE reports the preferred unitary precoding (i.e., preferred matrix index). PU2RC with full feedback: UE reports all the CQIs corresponding to all the unitary precoding. Using the spatial channel information fed back from the receivers, the trans- mitter can select a relevant unitary precoding. Because multiple users can be scheduled even in the same time-frequency resource and they are assigned dif- ferent beams, PU2RC-MIMO realizes SDMA. In fact, because a single user's multiple code words can also be scheduled even in the same time-frequency resource, PU2RC realizes SDM. When a single user's single code word is trans- mitted in a single beam, PU2RC performs closed-loop beam forming. To support closed-loop beam forming, UE needs to report the preferred beam in the preferred unitary precoding (i.e., preferred vector index as well as preferred matrix index). Given a matrix in the set E, the node B will use the following procedure: PU2RC with partial feedback; gather the feedback information, which indicates "a preferred precoding matrix" and the CQI values for all the precoding vectors in the matrix; group users who declare the same preferred precoding matrix; select a group with the highest group priority; how to define the group pri- ority depends on the scheduling policy; select code words of multiple users with the highest priority in the selected group; how to define the code word priority (or user priority) depends on the scheduling policy; apply appropriate AMC schemes to the selected code words; and apply a precoding scheme