Besides high bandwidth requirements and coverage areas, studies on 5G are also focused on issues such as large numbers of users, capacity, low latency, and secure communications. In addition to human communication, machine type communication (MTC), which requires specialized communication types with different needs, is one of the main research topics. Three basic MTC communication scenarios are proposed in this context, as Extreme Mobile BroadBand (xMBB), Ultra-reliable MTC (uMTC) and Massive Machine-Type Communications (mMTC). In this study, mMTC scenarios will be discussed. For mMTC, nonorthogonal multiple access (NOMA) schemes are proposed instead of Orthogonal Multiple Access (OMA), which is used in the communication infrastructure before 5G. One of the NOMA types, code-based access, will be mentioned. Especially on SCMA (Sparse Code Mutiple Access), which is likely to be a prospect standard from code-based access techniques, the influence of code books, receiver structures and BER performance analysis have been investigated. The performance of the codebook design is shown through simulations.