授权频谱辅助接入技术(License Assisted Access,LAA)可以把LTE网络部署在未授权频段上.为了与Wi-Fi网络友好共存,LAA网络采用先听后说(Listen Before Talk,LBT)机制.但是,LAA和Wi-Fi共存网络的性能很大程度上取决于LBT中的退避机制,而...授权频谱辅助接入技术(License Assisted Access,LAA)可以把LTE网络部署在未授权频段上.为了与Wi-Fi网络友好共存,LAA网络采用先听后说(Listen Before Talk,LBT)机制.但是,LAA和Wi-Fi共存网络的性能很大程度上取决于LBT中的退避机制,而竞争窗口的增加则是由当前传输机会(Transmission Opportunity,TXOP)的混合自动重传请求(Hybrid Automatic Repeat Request,HARQ)反馈情况来决定的.为此,本文首先利用LightGBM等6种机器学习算法,对TXOP第一个子帧的HARQ反馈的NACK占比是否达到80%进行了预测,由于LightGBM算法91.6%的准确率和0.98的AUC值(Area Under Curve),故选其作为实时预测模型.结果表明,采用了本文所提出的竞争窗口自适应预调整机制的LAA/Wi-Fi混合网络相比于没有采用该机制的LAA/Wi-Fi混合网络,吞吐量提升了21.266%.展开更多
The rapid boosting in mobile traffic and the scarcity of available radio spectrum have hindered the improvement of capacity in cellular networks.It is necessary to discover an appropriate coexistence between cellular ...The rapid boosting in mobile traffic and the scarcity of available radio spectrum have hindered the improvement of capacity in cellular networks.It is necessary to discover an appropriate coexistence between cellular and other radio access technologies(mainly Wi-Fi)to offload the high traffic on to unlicensed bands.Dealing with joint time and power allocation to devices,a non-convex problem is modeled to maximize the throughput as well as guarantee the desired user satisfaction.A two-step traffic balancing scheme is proposed to derive the solution.We also focus on the inner competition among cellular users instead of traditional competition between cellular and Wi-Fi in the unlicensed bands.Finally,simulation results show the effectiveness of the proposed two-step traffic balancing scheme.展开更多
基金supported by The National Natural Science Foundation of China(No.61471058)Beijing Nova Program(No.xx2012037).
文摘The rapid boosting in mobile traffic and the scarcity of available radio spectrum have hindered the improvement of capacity in cellular networks.It is necessary to discover an appropriate coexistence between cellular and other radio access technologies(mainly Wi-Fi)to offload the high traffic on to unlicensed bands.Dealing with joint time and power allocation to devices,a non-convex problem is modeled to maximize the throughput as well as guarantee the desired user satisfaction.A two-step traffic balancing scheme is proposed to derive the solution.We also focus on the inner competition among cellular users instead of traditional competition between cellular and Wi-Fi in the unlicensed bands.Finally,simulation results show the effectiveness of the proposed two-step traffic balancing scheme.
