Low Complexity Suboptimal Constellation Design for Multi-User Multiple Access

摘要

In a Non-Orthogonal Multiple Access (NOMA) uplink, the surjective-only mapping raised up by the linear combination of modulated symbols introduces uncertainty in the decoding process. And the computation complexity of detection algorithms increases exponentially. In this paper, we have proposed a mapping method based on sub-optimized signal constellation designs by shaping the receiver's constellation with a strategy that allows differentiate users, by which resolvable points will be received allowing simpler detection and design. Moreover, a novel multiplexing technique combining the frequency resource with a Time Delay (TD) is proposed as well.