Channel Estimation for STAR-RIS-Aided Wireless Communication
Channel Estimation for STAR-RIS-Aided Wireless Communication
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DOI：
10.1109/lcomm.2021.3139198
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发表时间：
2021-12
期刊：
影响因子：
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通讯作者：
Chenyu Wu;Changsheng You;Yuanwei Liu;Xuemai Gu;Yunlong Cai
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文献类型：
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作者：
Chenyu Wu;Changsheng You;Yuanwei Liu;Xuemai Gu;Yunlong Cai
在这封信中，我们研究了同步传输和反射可重构智能表面（STAR-RIS）辅助双用户通信系统的高效上行链路信道估计设计。我们首先考虑 STAR-RIS 的时间切换（TS）协议，并提出一种有效的方案，通过优化的训练（传输/反射）模式分别估计两个用户的信道。接下来，我们考虑实际耦合相移模型下的 STAR-RIS 能量分裂（ES）协议，并设计一个定制方案来同时估计两个用户的信道。尽管最小化 ES 协议所产生的信道估计误差的问题很难解决，但我们提出了一种有效的算法，通过联合设计导频序列、功率分流比和训练模式来获得高质量的解决方案。数值结果显示了所提出设计的有效性，并表明 TS 协议下的 STAR-RIS 实现了比 ES 情况更小的信道估计误差。
In this letter, we study efficient uplink channel estimation design for a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) assisted two-user communication systems. We first consider the time switching (TS) protocol for STAR-RIS and propose an efficient scheme to separately estimate the channels of the two users with optimized training (transmission/reflection) pattern. Next, we consider the energy splitting (ES) protocol for STAR-RIS under the practical coupled phase-shift model and devise a customized scheme to simultaneously estimate the channels of both users. Although the problem of minimizing the resultant channel estimation error for the ES protocol is difficult to solve, we propose an efficient algorithm to obtain a high-quality solution by jointly designing the pilot sequences, power-splitting ratio, and training patterns. Numerical results show the effectiveness of the proposed designs and reveal that the STAR-RIS under the TS protocol achieves a smaller channel estimation error than the ES case.