Joint Intra/Inter-Slot Code Design for Unsourced Multiple Access in 6G Internet of Things

• Published in: Sensors (Basel, Switzerland) Switzerland), 2022-12, Vol.23 (1), p.242
• Main Authors: Li, Yuanjie, Niu, Kai, Dong, Chao, Suo, Shiqiang, Lin, Jiaru
• Format: Article
• Language: English
• Subjects: 6G mobile communication; Algorithms; Analysis; Codes; Coding; degree distribution optimization; Design optimization; Energy efficiency; Error analysis; IDMA; Internet access; Internet of Things; Mathematical optimization; Multiple access; Optimization; Payloads; Signal to noise ratio; T-Fold IRSA; Telecommunication systems; unsourced multiple access
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s23010242

Unsourced multiple access (UMA) is the technology for massive, low-power, and uncoordinated Internet-of-Things in the 6G wireless system, improving connectivity and energy efficiency on guaranteed reliability. The multi-user coding scheme design is a critical problem for UMA. This paper proposes a UMA coding scheme based on the T-Fold IRSA (irregular repetition slotted Aloha) paradigm by using joint Intra/inter-slot code design and optimization. Our scheme adopts interleave-division multiple access (IDMA) to enhance the intra-slot coding gain and the low-complexity joint intra/inter-slot SIC (successive interference cancellation) decoder structure to recover multi-user payloads. Based on the error event decomposition and density evolution analysis, we build a joint intra/inter-slot coding parameter optimization algorithm to minimize the SNR (signal-to-noise ratio) requirement at an expected system packet loss rate. Numerical results indicate that the proposed scheme achieves energy efficiency gain by balancing the intra/inter-slot coding gain while maintaining relatively low implementation complexity.