Sigma-delta radio over fiber (ΣΔ-RoF) is an expedient technology for next-generation networks including 5G cloud/centralized radio access networks (C-RAN). In this article, we demonstrate a realistic experimental scenario for ΣΔ-RoF link targeting C-RAN fronthaul applications, by using baseband second-order 1-bit sigma-delta modulation (ΣΔ-M). The experimental set-up validates the LTE 20 MHz signals having modulation order of 256-quadrature amplitude modulation for a carrier frequency of 3 GHz, up to 10 km of standard single mode fiber. A detailed analysis of the ΣΔ-RoF system performance is reported by adjacent channel leakage ratio and error vector magnitude. Furthermore, an experimental study is evaluated where ΣΔ-RoF is compared with its counterparts. It is deduced that ΣΔ-RoF corroborates the present range of C-RAN fronthaul networks and can be a promising candidate for future mobile haul applications.

中文翻译：

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用于前传应用的实时 sigma-delta 光纤系统的实验评估

Sigma-delta 光纤无线电 (ΣΔ-RoF) 是一种适用于包括 5G 云/集中式无线电接入网络 (C-RAN) 在内的下一代网络的权宜之计技术。在本文中，我们通过使用基带二阶 1 位 sigma-delta 调制 (ΣΔ-M)，演示了针对 C-RAN 前传应用的 ΣΔ-RoF 链路的真实实验场景。实验装置验证了 LTE 20 MHz 信号，其调制阶数为 256 正交幅度调制，载波频率为 3 GHz，标准单模光纤长达 10 km。对 ΣΔ-RoF 系统性能的详细分析由相邻信道泄漏率和误差矢量幅度报告。此外，还评估了一项实验研究，其中将 ΣΔ-RoF 与其对应物进行了比较。