过载率对上行SCMA系统影响分析

Impact of overload factor on uplink SCMA system

稀疏码多址接入(sparse code multiple access,SCMA)以其优异性能成为5G多址接入技术的热门候选,而海量接入是5G所面临的主要挑战之一,SCMA自然要承受过载传输的考验。针对这一问题,探究了上行SCMA系统在不同过载传输场景中的性能表现。首先,从误码率性能与检测复杂度两个方面,分析系统过载率对系统检测译码的影响;其次,通过建立系统过载率与系统平均和速率的关系模型,分析系统过载率对系统传输速率的影响;最后,通过实验仿真验证分析的合理性与准确性。

Sparse code multiple access （SCMA） is regarded as a promising multiple access technology for 5G because of its excellent performance. One of the major challenges that 5G networks are facing is the massive connectivity in terms of both data volume and the number of devices, thus SCMA must be capable of coping with transmission overload. Analyzing the performance of the uplink SCMA system in overloading scenarios was focused on. At first, the influence of the overloading factor on the detection and decoding complexities and error performances of the uplink SCMA system were analyzed. Then, by establishing the relationship between the overloading factor and the average sum-rate, the impact of the overloading factor on the transmission rate of the uplink SCMA system was analyzed. Extensive numerical results are provided to verify the accuracy and insights derivable from the analytical results.