中文摘要：

针对基于OFDMA技术的MIMO中继通信系统下行链路中的动态资源分配问题，提出了一种保证最低用户服务质量（QoS）的资源分配方法。该方法采用一种低复杂度的次优算法，在假设等功率分配的前提下，根据用户的QoS定义选择优先性权衡因子，对权衡因子越大的用户越优先进行中继选择和子载波分配，在此基础上通过凸优化理论得到不同用户对应的子载波上的功率分配。仿真结果表明，本文提出的方法不但能够获得较高的系统容量，而且可以较好地保证每个用户的QoS。

英文摘要：

For the resource allocation in OFDMA MIMO relay downlink system, a quality of service aware resource allocation scheme with low complexity under total power constraint was proposed. First, under the assumption of equal power allocation, a selective priority factor was chosen for the relay selecting and subcarrier allocation. The relay selection and subcarriers allocation were carried out depending on the priority factor. Then the optimal power allocation was implemented through convex optimization algorithm. Numerical results show that the proposed scheme can not only achieve the higher capacity of system, but also guarantee the quality of service for each user.