基于协作干扰抑制的信道估计技术研究

Channel Estimation Based on Cooperative Interference Suppression

针对放大转发(AF)协作中继网络,为了高效获取级联和单跳链路的信道状态信息(CSI),本文设计一种组合训练方案。新方案采用时分(TM)训练和叠加训练(ST)相结合的(TM+ST)方式,在源节点采用TM训练方式完成级联(S-R-D)信道的估计,而在中继节点将训练序列叠加到接收信息序列之上,完成单跳(R-D)信道估计。为消除协作信息对R-D信道估计的干扰,提出了一种基于协作干扰抑制(CIS)的信道估计方法。新方法利用直传(S-D)链路信息来抑制协作中继链路(S-R-D)协作中的协作信息干扰,从而有效提高单跳信道估计性能。本文提出的方案采用两种训练方式将单跳和级联信道估计分离,有效降低训练序列的设计复杂度,仿真结果表明了新方案的有效性。

In an amplify-and-forward （AF） cooperative relay network, the combined training scheme is proposed to acquire channel state information （CSI） of different links. The combined training mode consists time-division multiplexing （TM） training and superimposed training （ST）, where the TM training is employed at source node to estimate the cascaded chan- nel （S-R-D） while the relay training sequence is added on top of the information-beating received signal to estimate the second-hop channel （R-D）. In order to improve the estimation performance of R-D link, a novel cooperative interference suppression （CIS） scheme is proposed to remove cooperative data interference using detected symbols of S-D links. The new scheme employs combined training mode to make the individual channel and cascaded channel estimated independent- ly, decreasing the complexity of training sequence design. Simulation results are presented to validate the performance of the proposed schemes.