Systems and methods for modulation and coding scheme selection and configuration

An apparatus for a radio access network, comprising:

• one or more processors;
• and
• one or more hardware storage devices having stored thereon computer-executable instructions that are executable by the one or more processors to cause the apparatus to perform the following:
• determine a first modulation and coding scheme (MCS) according to a default MCS table;
• determine a second MCS according to a secondary MCS table, the secondary MCS table comprising an entry corresponding to a 256-quadrature amplitude modulation (QAM) scheme;
• generate a radio resource control (RRC) layer message for a user equipment (UE), the RRC layer message indicating the secondary MCS table is to be used and indicating a maximum soft buffer size to be used by the UE and the apparatus regardless of which MCS table and which of a default channel quality indicator (CQI) table or a secondary CQI table are active, wherein a size of the buffer is based on a total number of soft channel bits associated with the UE, and wherein the maximum soft buffer size of the UE is configured for the secondary MCS table and the secondary CQI table, the secondary CQI table comprising an entry corresponding to a 256-QAM scheme;
• decode a CQI report from the UE, the CQI report including a differential CQI value, the differential CQI value being associated with the secondary CQI table, wherein the CQI report also includes a first CQI value, the first CQI value being determined based on a first codeword, wherein the differential CQI value is also associated with an offset level of a second codeword, the offset level of the second codeword being based on the first CQI value and a second CQI value that is determined based on the second codeword;
• select one of the default MCS table and the secondary MCS table based on the CQI report and availability of the secondary MCS table;
• and
• generate downlink control information (DCI) for the UE, the DCI having a DCI format that is selected based on the selected one of the default MCS table and the secondary MCS table, wherein the generated DCI includes a modulation and coding scheme value that indicates an entry of an MCS to be used during an ambiguity period, wherein the MCS is common to both the default MCS table and secondary MCS table.