Modulation and coding scheme in SCMA communication system

Communication networks of future generations should provide a high level of spectral efficiency. The multiple access method is one of the technologies that directly affect this parameter. During the discussion of fifth-generation communication networks, a new approach to designing the non-orthogonal multiple access was proposed. One of the implementation techniques of this approach is sparse code multiple access. In the article, we consider this method and propose an approach to the development of a modulation code scheme to evaluate the sparse code multiple access performance and efficiency under transmission conditions close to reality. The approach is based on a similar modulation code scheme of existing communication systems. To form sparse code multiple access symbols, a codebook based on the mother constellation rotation and interleaving method is considered. We also introduce a modulation code scheme table for SCMA communication systems and evaluate their spectral efficiency.