Digital Signal Processing ( IF 2.9 ) Pub Date : 2021-02-08 , DOI: 10.1016/j.dsp.2021.102995 Yao Zhang , Longxiang Yang , Hongbo Zhu
The spectral efficiency (SE) of an uplink cell-free large-scale multi-input multi-output (MIMO) non-orthogonal multiple access (NOMA) system which relies on the superimposed pilot (SP) transmission strategy is investigated. Closed-form expressions of the achievable SE with the maximal ratio combining (MRC) receiver filters are derived and compared against the orthogonal multiple access (OMA) counterparts. Based on the tractable results, we quantitatively explore the impacts of the pilot training strategy, the OMA and NOMA schemes, the number of user equipments (UEs), the power balance factor between pilot and data signals, and the length of the coherent interval (CI) on SE enhancement. Several insightful conclusions are drawn by assuming that the SP interference in the data detection process can or cannot be perfectly eliminated from the data estimates. All the analytical results are verified by numerical simulation experiments.
中文翻译:
无小区大规模MIMO非正交多址系统的频谱效率
研究了依赖于叠加导频(SP)传输策略的无上行链路的大规模无输入大规模多输入多输出(MIMO)非正交多址(NOMA)系统的频谱效率(SE)。导出具有最大比率组合(MRC)接收器滤波器的SE的闭式表达式,并将其与正交多址(OMA)对应项进行比较。基于可预测的结果,我们定量地探索了飞行员训练策略,OMA和NOMA方案,用户设备数量(UE),飞行员信号和数据信号之间的功率平衡因子以及相干间隔长度( CI)增强SE。通过假设可以从数据估计中完全消除或无法完全消除SP检测中的SP干扰,得出一些有见地的结论。通过数值模拟实验验证了所有分析结果。