Analyzing Uplink Grant-Free Sparse Code Multiple Access System in Massive IoT Networks

Grant-free sparse code multiple access (GF-SCMA) is considered to be a promising candidate for future wireless networks. In this article, we focus on characterizing the performance of uplink GF-SCMA schemes in network with ubiquitous connections, such as Internet-of-Things (IoT) To provide tractable approach evaluate GF-SCMA, first develop theoretical model taking into account property multiuser detection (MUD) SCMA system. Then, error rate case codebook collision analyzed investigate reliability when reusing massive IoT For evaluation, accurate approximations both success probability and average symbol (ASEP) are derived. elaborate further, analytical results utilized discuss impact codeword degree GF-SCMA. After that, conduct comparative study between its variant, dense (DCMA), GF transmission offer insights effectiveness these two schemes. This facilitates system design practical implementation. Simulation show that denser codebooks can help support more user equipments (UEs) increase data network. Moreover, higher achieved by UE deployment at low thresholds since achieve overloading gain.