基于负载均衡的OFDMA双跳中继网络资源分配策略

为适应蜂窝小区内不同的用户分布,针对基于正交频分多址接入技术的双跳中继网络,提出了一种基于负载均衡的资源分配策略.考虑难以得到联合分配的最优解,在降低计算复杂度的前提下,采用分步式次优化分配.采用比例公平算法对子载波进行分配,并用数学建模的方法解决功率分配问题;根据凸规划和注水算法确定功率分配最优解需满足的条件,在逼近最优解的目标下,求得基站和中继站的发射功率.仿真分析结果表明,与传统的静态资源分配策略相比,提出的基于负载均衡的资源分配策略可以适应不同的用户分布和信道条件,系统吞吐率提高7.8%以上. 

Resource Allocation Scheme Based on Load Balancing for OFDMA Two-Hop Relay Networks

In order to accommodate different user distributions in cells, a resource allocation scheme based on load balancing (RALB) was proposed for OFDMA(orthogonal frequency division multiple access)-based two-hop relay networks (TRNs). Because of the difficulty to solve a joint optimization problem, a step-by-step suboptimal allocation scheme was provided under the precondition of reducing the computational complexity. The proportional fair algorithm was adopted to allocate sub-channels, and the math modeling for power allocation algorithm was introduced. Based on the convex optimization and the water-filling algorithm, the conditions to satisfy the optimal power allocation solution were determined, and the transmission powers of base station and relay stations were calculated for approaching the optimal solution. Extensive simulations demonstrate that compared with the traditional static resource allocation (SRA), the proposed RALB is adaptable to different user distributions and channel conditions and improves the system throughput by more than 7.8%.