摘要
节点参加协作波束成形会增加复杂度和能耗,因而中继处理方法和协作区域的选择对整个协作网络非常重要.协作机会波束成形算法,仅选择部分节点发送信号使得目的节点接收信号近似相干叠加,降低了实现复杂度,但最优节点选择矢量的计算复杂度随中继节点数呈指数增加.为了降低计算复杂度,提出了协作机会波束成形的门限算法,并讨论了最优协作区域的大小.理论分析表明,目的节点接收信噪比随节点密度线性增加,且最优协作区域仅覆盖源节点周边有限区域.
Due to the complexity and energy needed by relay nodes in collaborative beamforming,it is very important to process signals at relay nodes and select the cooperative region.Opportunistic collaborative beamforming only selects a subset of relay nodes to transmit signals and allows for low-complexity relay node hardware.However,the computation of the optimal selection vector scales exponentially with the number of available relay nodes.Thus,a low-complexity sub-optimal relay selection rule is proposed based on three selection thresholds,in which the optimal cooperative region is also discussed.Theoretical analysis shows that the received signal-to-noise ratio（SNR） obtained with the proposed scheme scales linearly with relay node density.It is also proved that the optimal cooperative region is limited to a small area around a source node.
基金
国家自然科学基金(60802008)
国家重点基础研究发展(973)计划(2007CB310602)资助
关键词
协作机会波束成形
协作网络
门限选择
opportunistic collaborative beamforming
collaborative network
selection thresholds
