弹性的光与无线前传融合接入网系统的关键技术研究

With the development of hybrid optical and wireless access networks, some significant problems are coming out. For example, the power consumption issue, the crosstalk problem and the low resource utilization caused by the “tidal effect” of user data traffic, etc. In this project, we propose an access network with the integration of wireless fronthaul and optical access system based on wavelength stacked PON networks. In order to solve the problems mentioned above 1) we develop the wavelength scheduling module for optimally allocating the wavelength resources between the wireless access network and fixed access network, and within these two systems. 2) Besides, by modeling the user resources and the virtualization of wavelengths, the resources will be shared, thereby reducing the power consumption and cost of the system. 3) To mitigate the Raman crosstalk between the multiple wavelengths transmission system, we propose two solutions based on data coding and photonic microwave high-pass filtering respectively. Based on our ongoing related research on optical access networks, we are researching the key technologies of the integrated network between the wireless front haul and optical access networks, and to develop a full-service next generation PON system with the properties of high transmission data rate, low cost and multiple users, and make our efforts to promote the generation access networks technology and application.

为了顺应未来光和无线接入网的发展趋势，解决因用户接入数据的”潮汐效应”而带来的资源利用率低问题，本项目提出一种基于波长堆叠无源光网络的光和无线前传融合的接入网系统。系统通过设计波长灵活调度的结构模块，使波长资源在光和无线接入子系统之间及两个子系统内部进行优化配置；通过建立接入用户资源模型，将波长虚拟化实现资源共享，从而降低接入网系统功耗和成本；提出基于电域编码和光子微波滤波的方案，来抑制多波长共传而带来的拉曼散射问题。本项目将在已开展的无源光网络相关技术的研究基础上，探索和验证光与无线前传融合接入网的关键技术，发展一种传输速率高、接入用户多、成本低的全业务接入的下一代接入网的解决方案，推动下一代新型接入网技术的研发和应用。

本项目基于未来光和无线接入网的发展趋势，解决因用户接入数据的”潮汐效应”而带来的资源利用率低问题，且提出一种基于波长堆叠无源光网络的光和无线前传融合的接入网系统。在此基础上，重点研究了：1）模拟的光与无线前传接入网系统和数字的光与无线前传接入网系统；2）混合接入系统中的拉曼散射，FWM，验证了基于编码方案的抑制方案；3）设计并成功仿真“潮汐效应”理论模型，建立基于波长堆叠PON光无线前传融合系统的波长共享以及优化的理论模型。其中，对于模拟系统，设计了基于F-OFDM和基于功率复用技术的光与无线融合前传系统、基于OQAM-OFDM的能够支持多业务的、异步传输系统；实现等效高速率的20km光纤的传输系统,实现单波长10Gb/s的至少4路波长的传输；针对系统中存在的关键技术：信道估计、ADC比特量化，弹性采样，系统PAPR降低，系统安全性等关键问题； 对于数字系统，实现了高速率、高分支比的接入网；实现了单波长的25Gb/s及50Gb/s,56Gb/s的单路和4路传输；设计了提高系统性能的改进型PAM4码型，结合TCM技术的新型的PAM8，提升系统性能的均衡算法等；最后，本项目组成员搭建了模拟的、数字的光与无线前传混合接入网系统的实验平台。这些成果可在一定程度为未来的5G甚至B5G的前传网络的发展，提供一定的技术支持。