User Activity Detection-Based Large SCMA System for Uplink Grant-Free Access

Sparse code multiple access (SCMA) is a promising non-orthogonal multiple access (NOMA) technology for next generation wireless networks to achieve higher spectral efficiency and lower latency in massive machine type communication systems. In the massive uplink grant-free communications, users can conduct uplink instant transmissions without grant to reduce signaling overhead as well as the latency. Multiusers' data symbols are detected...