A high-reliability optical network architecture based on wavelength division multiplexing passive optical network

A highly reliable wavelength division multiplexing passive optical network architecture for the fifth generation (5G) applications is designed by combining a tree topology with a dual-fiber ring. While the tree topology ensures the transmission quality of the network, the dual-fiber ring topology allows one to achieve flexible switching between the nodes, which aims to provide fault protection and network reliability. The signal transmission under the normal and three types of protection modes are analyzed. The performance analysis verifies the feasibility of the proposed architecture.     

基于分布式混合CSIT的MIMO X网络自由度分析

在M×N用户MIMO X网络中,发射端信道状态信息（CSIT）类型会影响系统总自由度（sum-DoF）.为逼近系统总自由度外界,设计MIMO X网络对称天线配置下的多阶段分布式空时干扰对齐（DSTIA）方案;推导具有分布式特性的基于混合CSIT—过期（outdated）和当前（current） CSIT的预编码矩阵闭式解;分析CSI反馈时延、网络节点数和配置天线数对MIMO X网络总自由度的影响.理论和数值分析表明,在分布式混合CSIT条件下,DSTIA方案能充分消除用户间干扰,获得更高的自由度,缩小可达界与外界的差距,提高系统可达速率.