Signal transmission or reception method and apparatus therefor in wireless communication system

A base station (BS) for transmitting a downlink signal in a wireless communication system, the BS comprising:

• a processor configured to modulate a first part of a codeword for a first User Equipment (UE) based on a first Modulation and Coding Scheme (MCS) and a second part of the codeword based on a second MCS;
• and
• a transmitter configured to transmit the modulated codeword to the first UE under control of the processor,
• wherein the second part of the codeword is transmitted together with a signal for a second UE on a same resource based on a Non-Orthogonal Multiple Access (NOMA) scheme, and
• wherein the second MCS for the second part, which is transmitted based on the NOMA scheme, has a modulation order lower than that of the first MCS for the first part.

A method for receiving a downlink signal by a first User Equipment (UE) in a wireless communication system, the method comprising:

• receiving a modulated codeword from a base station (BS);
• and
• demodulating a first part of the codeword based on a first Modulation and Coding Scheme (MCS) and a second part of the codeword based on a second MCS,
• wherein the second part of the codeword is received together with a signal for a second UE on a same resource based on a Non-Orthogonal Multiple Access (NOMA) scheme, and
• wherein the second MCS for the second part which is received based on the NOMA scheme, has a modulation order lower than that of the first MCS for the first part.

A User Equipment (UE) for receiving a downlink signal in a wireless communication system, the UE comprising:

• a receiver;
• and
• a processor configured to control the receiver to receive a modulated codeword from a base station (BS) and demodulate a first part of the codeword based on a first Modulation and Coding Scheme (MCS) and a second part of the codeword based on a second MCS,
• wherein the second part of the codeword is received together with a signal for another UE on a same resource based on a Non-Orthogonal Multiple Access (NOMA) scheme, and
• wherein the second MCS for the second part which is received based on the NOMA scheme, has a modulation order lower than that of the first MCS for the first part.