We investigate multiuser detection under uplink asynchronous scenario, where the triangular successive interference cancellation (T-SIC) detection scheme is exploited. As the existing analysis was conducted under some ideal assumptions for simplicity, the asynchronous scenario is analyzed under rigorous assumptions in this paper so that important insights are revealed for practical systems. Specifically, the average symbol error rate (SER) formulas are derived for a two-user system with arbitrary $M$ -ary quadrature amplitude modulation ( $M$ -QAM) over Rayleigh fading channels. These solutions are shown to have higher accuracies compared to the existing solutions. Furthermore, a novel iterative detection algorithm is proposed, i.e., the parallel T-SIC method, which is more efficient and effective compared to the iterative T-SIC method. Insightful discussion is conducted in terms of the potentials of the concerned iterative detection method. Simulation results show that the most significant improvement of the iterative detection reflects on the SER for the strongest user, and the reduction is always within 50% of the SER compared to the primary detection. The gains obtained by the iterative detection is negligible for higher order $M$ -QAM cases.

中文翻译：

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非正交多址上行异步信号检测误码率性能分析


我们研究了上行链路异步场景下的多用户检测，其中利用了三角连续干扰消除（T-SIC）检测方案。由于现有的分析是在一些理想的假设下进行的，因此本文在严格的假设下分析异步场景，以便为实际系统揭示重要的见解。具体来说，平均符号错误率（SER）公式是针对具有任意$M$三元正交幅度调制（ $M$ -QAM）通过瑞利衰落信道。与现有解决方案相比，这些解决方案具有更高的精度。此外，提出了一种新颖的迭代检测算法，即并行T-SIC方法，与迭代T-SIC方法相比，该算法更加高效和有效。针对相关迭代检测方法的潜力进行了富有洞察力的讨论。仿真结果表明，迭代检测最显着的改进体现在最强用户的SER上，与初次检测相比，SER的降低始终在50%以内。迭代检测获得的增益对于高阶可以忽略不计$M$ -QAM 案例。