This letter investigates the bit error rate (BER) performance of simultaneous transmitting and reflecting reconfigurable intelligent surfaces (STAR-RISs) in non-orthogonal multiple access (NOMA) networks. In the investigated network, a STAR-RIS serves multiple non-orthogonal users located on either side of the surface by utilizing the mode switching protocol. We derive the closed-form BER expressions in perfect and imperfect successive interference cancellation cases. Furthermore, asymptotic analyses are also conducted to provide further insights into the BER behavior in the high signal-to-noise ratio region. Finally, the accuracy of our theoretical analysis is validated through Monte Carlo simulations. The obtained results reveal that the BER performance of STAR-RIS-NOMA outperforms that of the classical NOMA system, and STAR-RIS might be a promising NOMA 2.0 solution.

翻译：此信调查了同步传输和反映可重新配置的智能表面(STAR-RIS)在非垂直多重访问网络中的比特错误率(BER)性能。 在被调查的网络中, STAR- RIS通过使用模式转换协议为位于地表两侧的多个非垂直用户服务。 我们用完美和不完善的连续取消干扰案例来得出封闭式BER的表达方式。 此外, 也进行了无症状分析, 以进一步深入了解高信号对音率区域的BER行为。 最后, 我们的理论分析的准确性通过Monte Carlo模拟得到验证。 获得的结果显示, Star-RIS- NOMA 的BAR性能超过了古典NOMA 系统, StAR- RIS 的性能可能是一个很有希望的NOMA 2.0 解决方案。