The present disclosure relates to a transmitter device and a receiver device. The transmitter device comprises a processor which is communicably coupled with a transmitter unit. The processor is configured to receive a set of Z data streams and select K data streams with the same channel quality from the set of Z data streams for transmission, where K≤Z. Thereafter for each information word and for each data stream k=0, . . . , K−1 the processor encodes, scrambles and superposes so as to obtain a first signal sU. Further, for each information word and for each data stream k=0, . . . , K−1 the processor interleaves, encodes, scrambles and superposes so as to obtain a second signal sV. The first signal sU and the second signal sV are combined by the processor into a single signal s for transmission. The transmitter unit of the transmitter device is configured to transmit the transmission signal s over a radio channel.