OFDMA用户协作系统的自适应资源分配

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。

Adaptive resource allocation in OFDMA system with user relay

In OFDMA systems enhanced with user coo perat io n, the pro posed co operat ion to impr ove the fr equency ef f iciency is that BS t ransmit s uninterr uptedly and the relay ing users decode-and-forw ard the first-slo t-received sig nal to the o bject ive users at the second slot , fo rming the tw o-slot s cooper at ive t ransmit w ith spat ial diversity. The pro posed opt imial scheme designs the ut ility funct ions based on the service character and the sum utility max imizat io n is realized by Lagrange and dual decompo sit ion, w hich bring s the joint opt imizations of subcarrier -pow er allocat ion and relay selectio n. T he simulatio n result s show that the user requirement can be guaranteed and the high ut ilizat io n is bet ter achieved w hen the pr opo sed scheme is used.