An apparatus serves a plurality of user equipments in a wireless communication system. For transmitting/receiving data of a plurality of user equipments, which include at least a first user equipment and a second user equipment, on resources shared by the plurality of user equipments, the apparatus transmits/receives a first data signal of the first user equipment and second data signal of the second user equipment using a non-orthogonal multiple access, NOMA, scheme. The first data signal and the second data signal are modulated using different waveforms prior to superposition of the first and second data signals.