为支撑随时随地要求高速接入的用户需求，下一代无线宽带下行网络将采用中继OFDMA传输技术，但是基站和中继站的电路设备会造成除发射功率之外的功率开销，导致网络能效性能显著降低。在降低运营成本和节能减排的双重迫切压力下必须提高网络能效。已有研究工作针对中继OFDMA下行网络设计了传输方案，并设计了节能或最大化能效的资源分配算法。但是，已提出通信机制以及资源分配算法不能灵活自由地充分利用网络资源，未能深入研究网络频谱效率对于能量效率的影响机理。本项目拟针对上述问题，在前期工作提出的基于机会式载波配对和波束成形(OSPBF:Opportunistic Subcarrier Pairing and Beam Forming)机制的基础上，建立网络能效模型，探索网络谱效对能效的影响机理，设计最大化网络能效的资源分配算法，为高能效中继OFDMA网络优化设提供理论依据和参考方案，具有理论和应用价值。

In order to support high data-rate user access at any time from any place, next-generation wireless broadband downlink networks will deploy relay-aided OFDMA transmission. However, the bases and relay stations lead to high power consumptions in addition to signal transmisison power consumption, which leads to a significant degradation of network energy efficiency (EE). Under the double pressure from reducing the operation cost and energy saving, the network EE must be improved. Current research work proposes transmission schemes and related resource allocation algorithms. However, the existing works can not freely utilize network resources at the best, and did not study in depth the impact of spectral efficiency on the EE. To address the above problems, this project will be based on the Opportunistic Subcarrier Pairing and Beam Forming transmission protocol proposed in previous work, establish an analytical model for network EE, explore the impact of network spectral efficiency on the EE, design resource allocation algorithms to maximize the EE, so as to provide theoretical support and reference methods for high-EE design of relay-aided OFDMA networks. This work has both theoretical and practical values.