Methods, systems, and devices for wireless communication are described. In wireless systems supporting multiple-input, multiple-output (MIMO) transmissions, devices may implement beam-forming to improve reliability of communications. A user equipment (UE) may select a set of beams, and corresponding beam indices, for communication based on reference signals received from a base station. The UE may determine values corresponding to each of the beam indices using a scalable set of tables. For example, the UE may select a subset of the tables based on the number of selected beams, and may determine the values based on these tables. In this way, the UE may efficiently store sets of tables for multiple different configurations. The UE may sum the corresponding values to obtain a combination index value, and may transmit the combination index value to the base station. The base station may determine the selected beams based on this combination index value.