Abstract
The invention discloses a base station and a modulation method supporting lattice-partition-based downlink non-orthogonal multiple access. The modulation method includes: modulating at least one most significant bit (MSB) of weak user equipment (UE) into a first signal with first transmission power; modulating at least one least significant bit (LSB) of the weak UE into a second signal with second transmission power, where the second transmission power is less than the first transmission power; and modulating at least one second MSB of strong UE into a third signal with third transmission power, where the third transmission power is between the first transmission power and the second transmission power.