A method of operating a user equipment communicating with a base station of a radio access network may include selecting a multiple-input-multiple-output, MIMO, rank and a MIMO precoding entity from a codebook of MIMO precoding entities for a downlink communication from the base station to the user equipment. A modulation/coding scheme to be mapped to first and second MIMO layers of the downlink communication may be selected using the MIMO precoding entity. Channel quality information may be communicated identifying the MIMO precoding entity and the modulation/coding scheme from the user equipment to the base station. Related user equipment nodes are also discussed.