OFDMA中继网络变时域节能资源分配策略

Variable Time-domain Energy Saving Resource Allocation for OFDMA Relay Networks

现有正交频分多址接入(OFDMA)中继网络资源分配的研究均采用固定时域配置下的频域分配和功率分配,不能很好适应用户业务在时域上的变化。该文针对OFDMA中继网络提出一种可最优节能的资源分配策略和一种简化的节能资源分配策略,为资源分配问题建立一般化的模型,即动态分配时域资源、频域资源和功率资源,所建模型具有很强的灵活性和适应性,不仅适用于固定时域分配系统,也适用于非固定时域分配系统。此外针对非满负荷业务,在保证用户服务质量的情况下,以节能为目标对无线非协作中继网络的资源分配进行能效最大化建模,使用拉格朗日乘数法对模型求解。考虑到算法复杂度,应用指派问题中的匈牙利算法设计出一种简化的资源分配策略。理论和仿真结果表明,最优节能资源分配算法能够得到能效的最大化,而简化节能资源分配算法与最优节能资源分配算法在能效上的差距不足5%,但算法复杂度得到了显著降低。而且,动态分配时域资源比固定时域分配对用户分布不均或链路分布不均有更强的适应性。

The existing resource allocation research for OFDMA relay networks investigate only frequency-domain allocation and power allocation with fixed time-domain allocation,which can not fit the user service changes in time-domain.An optimal energy-efficient resource allocation strategy and its simplified version are proposed for OFDMA relay network.A generalized model for resource allocation issue,which dynamically allocates time-domain,frequency-domain resources and power resources,is established.Due to the strong flexibility and adaptability,the model may apply to not only the fixed time-domain allocation system,but also the non-fixed time-domain allocation system.For non-full-buffer traffic,to ensure the users’ quality of service,an energy-efficiency maximization model is established for OFDMA non-cooperative relay networks by using the Lagrange multiplier algorithm to solve the issue.Taking into account the complexity of the algorithm,a simplified resource allocation strategy is proposed by using the Hungarian method.The theory and simulation results show that the optimal algorithm can get the energy-efficiency maximization,and the energy-efficiency difference between the simplified algorithm and the optimal algorithm is less than 5%,however,the complexity has been significantly reduced.Moreover,the dynamic time-domain allocation has more adaptive in uneven user distribution or link distribution than fixed time-domain allocation.