Network Coded Modulation for Next Generation Wireless Access Networks

鉴于对移动数据服务的需求迅速增加，下一代无线接入网必须提供大大增加的容量密度，达到每平方公里10 Gbps。这将需要更大密度的非常小、廉价和节能的基站，并将对网络，特别是回程网络的带宽和能源效率提出越来越高的要求。最近在网络MIMO或协调多点（CoMP）方面的工作表明，通过确保基站合作为用户服务，特别是那些靠近蜂窝边缘的用户，而不是相互干扰，可以有效地消除用户间的干扰，大大提高网络的效率，在频谱和能量方面。然而，这往往会大大增加回程负载。这项工作提出了一种称为网络编码调制的无线网络编码形式，作为传统CoMP的替代方案。这也可以实现基站合作，但不是向每个基站发送多个单独的信息流，而是使用网络编码将信息流组合在一起，原则上允许合作，与非合作传输相比，回程负载不会增加，同时在带宽和能效方面获得与CoMP非常相似的优势。提出的工作目标是确定这种方法的实际可行性，并评估其应用于下一代无线接入网络的好处。为此，它将开发实用的信令方案、网络协调和管理协议，并在工业合作者的帮助下，确保与正在开发的无线标准的兼容性。

In view of the rapid increase in demand for mobile data services, next generation wireless access networks will have to provide greatly increased capacity density, up to 10 Gbps per square kilometre. This will require a much larger density of very small, cheap and energy-efficient base stations, and will place increasing demand on the bandwidth and energy efficiency of the network, and especially the backhaul network. Recent work on network MIMO, or coordinated multipoint (CoMP) has shown that by ensuring base stations cooperate to serve users, especially those close to cell edge, rather than interferring with one another, inter-user interference can be effectively eliminated, greatly increasing the efficiency of the network, in terms of both spectrum and energy. However this tends to greatly increase the backhaul load. This work proposes a form of wireless network coding, called network coded modulation, as an alternative to conventional CoMP. This also enables base station cooperation, but instead of sending multiple separate information flows to each base station, flows are combined using network coding, which in principle allows cooperation with no increase in backhaul load compared to non-cooperative transmission, while gaining very similar advantages to CoMP in terms of bandwidth and energy efficiency. The objective of the proposed work is to establish the practical feasibility of this approach, and evaluate its benefits, as applied to next generation wireless access networks. To this end it will develop practical signalling schemes, network coordination and management protocols, and, with the help of industrial collaborators, will ensure compatibility with developing wireless standards.