This letter studies the performance of the simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) aided non-orthogonal multiple access (NOMA) networks in support of ultra-reliable low-latency communications. We adopt effective capacity (EC) as the metric to explore the delay requirements of NOMA users. Specifically, the analytical expressions of the EC are obtained for the network with a pair of NOMA users on the different sides of the STAR-RIS. Furthermore, the high signal-to-noise ratio (SNR) slope and high SNR power offset are invoked to provide asymptotic analysis of the ECs in high SNR. Some insightful conclusions are drawn from the simulations: 1) the EC of near user $({U_{n}})$ increases linearly while the EC of far user $({U_{m}})$ tends to be a constant in the high SNR; 2) comparing with STAR-orthogonal multiple access and conventional RIS, the use of STAR-RIS NOMA increases the ECs of ${U_{n}}$ and overall network; 3) increasing the number of STAR-RIS elements is an effective strategy to improve the ECs of both ${U_{n}}$ and ${U_{m}}$ .

中文翻译：

---

STAR-RIS 辅助 NOMA 网络的有效容量分析

这封信研究了同时传输和反射的可重构智能表面 (STAR-RIS) 辅助非正交多址 (NOMA) 网络的性能，以支持超可靠的低延迟通信。我们采用有效容量（EC）作为衡量 NOMA 用户延迟需求的指标。具体而言，对于在 STAR-RIS 不同侧具有一对 NOMA 用户的网络，获得了 EC 的解析表达式。此外，调用高信噪比 (SNR) 斜率和高 SNR 功率偏移来提供高 SNR 中 EC 的渐近分析。从模拟中得出了一些有见地的结论：1）近用户的EC $({U_{n}})$远用户的 EC 线性增加 $({U_{m}})$在高信噪比下趋于恒定；2) 与 STAR-正交多址和传统 RIS 相比，使用 STAR-RIS NOMA 增加了 ${U_{n}}$和整体网络；3）增加STAR-RIS元素的数量是提高两者EC的有效策略 ${U_{n}}$和 ${U_{m}}$ .