稀疏码多址接入，就是应5G需求设计产生的一种非正交多址技术。在发送端通过多维调制和稀疏扩频将编码比特映射成SCMA码字，接收端通过多用户检测完成译码。-Sparse code multiple access is a kind of non orthogonal multiple access technology, which should be produced by the design of 5G demand. The cod