分布式放大前传中继辅助多用户对等通信中的鲁棒波束成形

针对分布式放大前传中继辅助多用户对等通信系统研究了存在非理想信道状态信息(CSI)时的分布式中继网络(DRN)鲁棒波束成形设计问题。采用统计CSI误差模型,考虑了两种鲁棒优化问题:一是从公平性的角度出发在DRN总发送功率约束下实现多个目的节点间的信干噪比(SINR)平衡;另一是从有效性的角度出发在保证各个目的节点服务质量需求(SINR大于预设门限)约束下最小化DRN总发送功率。对问题的分析和建模表明,在多用户情况下,这两个问题都是难以求解的优化问题。通过引入半定松弛(SDR)思想,将上述两种优化问题转化为可利用内点法有效求解的半定规划(SDP)问题。最后通过仿真验证了所提设计的鲁棒性能。

Robust Beamforming for Distributed Amplify-and-Forward Relay Aided Multiuser Peer-to-Peer Communications

This study addresses the robust distributed relay network (DRN) beamforming design problems for a distributed Amplify-and-Forward (AF) relay aided multiuser peer-to-peer communication system in the presence of imperfect channel state information (CSI). Adopting a stochastic CSI error model, two robust optimal design problems are considered. One is aimed at balancing the signal-to-interference plus noise ratio (SINR) at desitinations under the DRN total transmit power constraint concerning the fairness, the other is to minimise the DRN total tranmit power with guarantee of QoS requirements (SINRs exceed preassign thresholds) at destinations concerning the efficiency. The analysis and modeling indicates that the problems above are the intractable problems. By introducing the semidefinite relaxation (SDR) technique, the intractable problems hereinbefore can be converted into semidefinite program (SDP) problems that can be solved efficiently using interior-point methods. The robust performance of the proposed designs is demonstrated through simulations.