摘要
针对OFDMA用户协作系统,为提高频谱效率,提出基站不间断地发射信号,中继用户将基站在第一时隙发射的信号以DF方式在第二时隙转发给目标用户的协作传输方案,从而在2时隙对目标用户构成具有空间分集。以效益和最大为目标,提出根据业务特性合理设计效益函数,并采用拉格朗日对偶方法实现联合子载波、功率分配和中继选择的优化方案。仿真结果表明,相对于已有方法,该方案提高了频谱利用率且更有效地满足了用户需求。
In OFDMA systems enhanced with user cooperation,the proposed cooperation to improve the frequency efficiency is that BS transmits uninterruptedly and the relaying users decode-and-forward the first-slot-received signal to the objective users at the second slot,forming the two-slots cooperative transmit with spatial diversity.The proposed optimial scheme designs the utility functions based on the service character and the sum utility maximization is realized by Lagrange and dual decomposition,which brings the joint optimizations of subcarrier-power allocation and relay selection.The simulation results show that the user requirement can be guaranteed and the high utilization is better achieved when the proposed scheme is used.
出处
《解放军理工大学学报（自然科学版）》
EI
北大核心
2010年第6期596-601,共6页
Journal of PLA University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(60872149
61072088)
