中文摘要：

对基于物理层网络编码的正交频分复用（OFDM）双向中继系统中的无线资源分配问题进行了研究，在总功率和用户对速率受限条件下，给出了一种复杂度较低，以最大化系统容量为目标的资源分配策略．利用凸优化技术对子载波内的用户终端和中继节点的功率分配问题进行分析，得到用户终端和中继节点的功率闭合关系表达式．基于该结果，将原优化问题中的三维变量搜索降低为一维变量搜索，较大地降低了算法的复杂度．仿真结果表明，在多种典型场景中，所提方案较传统随机调度分配方案有较大的性能提升，且逼近最优分配方案的性能．

英文摘要：

An optimal resource allocation scheme for an orthogonal frequency-division multiple （OFDM） two-way relay network with physical network coding is constructed. Considering the total transmit power and user rate constraints, a sub-optimal resource allocation scheme is proposed to maximize the achievable sum rate of the terminals with low complexity. Using convex optimization techniques, a closed-form solution for power allocation among relay node and two terminals is derived. Thereafter, the variable dimensionality of the objective function is reduced from 3 to 1 that can dramatically decrease the complexity of the solution. Simulation shows that the proposed approach achieves the optimal sum rate and is better than that of the traditional resource assignment method but with less computational load in various scenarios.