将中继OFDMA系统的资源分配问题建模成一个在每个接入节点功率受限,以及满足每个用户最小速率要求的条件下,最大化系统容量的数学模型,提出了一种基于对偶分解的资源分配算法,将该问题分解成若干个关于各个子载波的子问题进行求解,从而有效地降低了计算的复杂度.通过对各子问题的求解,可以获得最优的中继节点的选择方案以及功率、子载波的分配方案.仿真结果表明,该算法能够在保障不同用户速率需求的前提下,有效地提高系统的容量.

In this paper,first,the problem of resource allocation of relay OFDMA systems is described as a mathematical model with power-limited access nodes and maximum system capacity,which meets the requirements of miminum rate of each user.Then,a resource allocation algorithm based on dual decomposition is proposed,which decomposes the problem into several subproblems of subcarriers,thus effectively recuding the calculation complexity.By solving the subproblems,optimal schemes of relay node selection,power allocation and subcarrier assignment can be obtained.Simulated results show that the proposed algorithm effectively improves the system capacity and simultaneously meets the rate requiremnets of each user.