无线中继网络是下一代通信网络中的一个重要组成部分。本项目将网络编码应用于半双工中继网络，旨在提高整个网络的多播吞吐量。受半双工中继无法同时接收和发送数据的制约，以及无线信道的时变性，如何设计合理的编码方案，并对中继基站进行合理的多播优化调度，便成为了关系到整个网络多播吞吐量的关键问题。本项目拟从编码节点选择、编码方法选择、编码参数选择等方面综合考虑，针对不同的网络环境，设计相应的网络编码方案。其次，根据所提出的编码方案，设计相应的中继多播调度算法。由于传统的基于动态规划技术的研究方法存在严重的局限性（只能应对小规模网络），本项目拟利用流体模型对多播调度问题进行建模，得出与之对应的流体近似问题；通过研究与求解流体问题，并对流体问题的解进行合理的调整与转化，最终设计出有效的多播调度算法。最后，重点研究所提出算法的渐进表现，并通过仿真对算法的性能进行检验。

Wireless relay network is a key component in the next generation communication networks. We apply network coding in half-duplex relay networks for purpose of multicast throughput enhancement. Due to the half-duplex operation of the relay station (it cannot receive and transmit simultaneously) and the time-varying capacity of wireless channels, it is important to design proper coding schemes and multicast scheduling policies for the relay station. In this project, we first design coding schemes by jointly considering coding node selecting, coding method selecting and coding parameters selecting for different network scenarios. Then we design the associated multicast scheduling policies for each proposed coding scheme. Since the traditional dynamic programming approaches have scalability issues when the network size is large, we use the fluid model to approximate the multicast scheduling problem. Based on the solution to the fluid problem, we propose efficient multicast scheduling policies. At last, we analyze the asymptotic performance of our policies, and also we verify the efficiency of our policies via simulation.