Method and device for transmitting signal in communication system supporting multi-user access

A method for receiving a signal in a communication system supporting multi-user access, the method comprising:

• receiving, by a reception apparatus, information indicating a codebook configured based on at least two signal constellations for sparse code multiple access (SCMA) transmission from a transmission apparatus;
• and
• receiving, by the reception apparatus, signals based on the codebook from the transmission apparatus,
• wherein the at least two signal constellations are generated by applying a scaling factor to a given mother signal constellation, and
• wherein the scaling factor is generated based on energy values of symbols of the given mother signal constellation and magnitudes of the symbols of the given mother signal constellation.

An apparatus for transmitting a signal in a communication system supporting multi-user access, the apparatus comprising:

• a transceiver;
• and
• a processor configured to control the transceiver to:
• transmit information indicating a codebook configured based on at least two signal constellations for sparse code multiple access (SCMA) transmission to a reception apparatus, and
• transmit signals based on the codebook to the reception apparatus,
• wherein the at least two signal constellations are generated by applying a scaling factor to a given mother signal constellation, and
• wherein the scaling factor is generated based on energy values of symbols of the given mother signal constellation and magnitudes of the symbols of the given mother signal constellation.