Comparison of Codebooks for Non-Orthogonal Multiple Access SCMA

• Published in: Systems of Signals Generating and Processing in the Field of on Board Communications (Online) pp. 1 - 5
• Main Authors: Timoschuk, Julia, Rejeb, Taoufik Ben
• Format: Conference Proceeding
• Language: English
• Published: IEEE 12.03.2025
• Subjects: Codes; Fading channels; Low latency communication; Maximum likelihood decoding; Multiple Access; NOMA; Optimization Problem; Rayleigh Fading Channel; Resilience; Reviews; Sparse Code Multiple Access; Spectral efficiency; Throughput; Wireless Communications; Wireless networks
• ISSN: 2768-0118
• DOI: 10.1109/IEEECONF64229.2025.10948093

The ever-increasing demand for high-capacity and low-latency communications in next-generation wireless networks has driven the evolution of advanced multiple access techniques. Among these, Sparse Code Multiple Access (SCMA) has emerged as a promising non-orthogonal multiple access (NOMA) scheme, offering the advantages of massive connectivity and enhanced spectral efficiency through the use of sparse multidimensional codebooks. This paper presents a comprehensive comparative analysis of various SCMA codebook designs under realistic fading channel conditions. In this work, we review key NOMA paradigms-from power-domain to codedomain techniques-and examine the SCMA system framework, highlighting the critical role of sparsity in codebook construction. In addition, decoding techniques, notably the message passing algorithm (MPA) and maximum likelihood (ML) detection, are discussed in terms of their trade-offs between performance and computational complexity. The insights gained from this study offer practical guidelines for optimizing SCMA systems, thereby contributing to the development of robust and efficient communication frameworks for future 5G-Advanced and 6G networks.