Scma: A Promising Non-Orthogonal Multiple Access Technology For 5g Networks

Sparse code multiple access (SCMA) is a code domain non-orthogonal multiple-access technique introduced for future 5G wireless networks. This paper describes the basic ideas of SCMA, the SCMA codebook design, the encoder and decoder, as well as the SCMA enabled transmission schemes for different application scenarios, including uplink grant-free contention-based transmission, downlink multi-user superposition, and downlink open-loop CoMP for ultra-dense networks even with moving users. We shall show from design principles and application examples that SCMA can resolve some major issues of current wireless systems and establish itself as a strong candidate for 5G networks.(1)