中继OFDMA系统容量公平资源分配算法研究

Resource allocation for relay OFDMA system with proportional fairness

针对OFMDA解码-转发中继系统的资源分配问题,提出了一种以系统总功率和用户间的数据速率比例公平为约束条件,以最大化系统总速率为目标的资源分配算法。该资源分配问题为非线性最优化问题,联合求解所有变量复杂度很高,通过次优化的方法降低计算复杂度。算法包括:子载波分配和功率分配。子载波分配是以功率平均分配为前提,对基站-中继站和中继站-用户链路的子载波按照信道条件进行配对,并根据比例公平约束将配对的子载波分配给相应的用户。功率分配是对每个用户利用Lagrange方法调整每个子载波的功率,进一步提高系统的数据速率。算法仿真分析表明,该算法既能同时满足多用户不同数据速率的要求,又能提高系统的数据速率。

A resource allocation algorithm is proposed for decoding and forward Orthogonal Frequency Division Multiple Access（OFDMA） relay system.The objective is to maximize the system capacity with the total power constraint,while guaranteeing proportional fairness of multiple users.The resource allocation problem is a nonlinear optimal problem and the complexity is very high.In order to lower the complexity of problem,the proposed suboptimal algorithm includes two steps：Subcarrier allocation and power allocation.The subcarriers of source-relay channel and relay-destination channel are paired according to the channel state information of two hops,and with equal power allocation.The subcarrier pairs are allocated to users under the proportional fairness constraint.The power allocation is implemented with Lagrange method for every user.Simulation results show that the proposed algorithm can satisfy every user data rate requirements and have a better performance than other algorithms.