Multi-panel MIMO is a promising technology in millimeter wave communications. Due to its partially hybrid structure and non-uniform antenna array, existing channel estimation cannot be directly applied to multi-panel MIMO. In this paper, we study channel estimation for multi-panel mmWave MIMO. We firstly model channel estimation of multi-panel MIMO as a block-sparse signal recovery problem. Then, according to maximum likelihood criterion, we propose an orthogonal projection method to firstly detect the support of the sparse channel response vector and then perform least square estimation, based on which we also propose a low-complexity greedy support detection in order to reduce computational complexity. Finally, through analyzing pairwise error probability of support detection, we verify the performance gain of joint multi-panel channel estimation over single panel channel estimation, and we further find that joint multi-panel channel estimation with independently generated random combining matrices outperforms that with identically generated combining matrices. Numerical results verify the superiority of our proposed joint multi-panel orthogonal projection based channel estimation over existing schemes.

中文翻译：

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基于正交投影的多面板毫米波 MIMO 信道估计

多面板 MIMO 是毫米波通信中一项很有前途的技术。由于其部分混合结构和非均匀天线阵列，现有的信道估计不能直接应用于多面板 MIMO。在本文中，我们研究了多面板毫米波 MIMO 的信道估计。我们首先将多面板 MIMO 的信道估计建模为块稀疏信号恢复问题。然后，根据最大似然准则，我们提出了一种正交投影方法，首先检测稀疏信道响应向量的支持，然后进行最小二乘估计，在此基础上我们还提出了一种低复杂度的贪婪支持检测，以减少计算量。复杂。最后，通过分析支持检测的成对错误概率，我们验证了联合多面板信道估计相对于单面板信道估计的性能增益，我们进一步发现具有独立生成的随机组合矩阵的联合多面板信道估计优于具有相同生成组合矩阵的联合多面板信道估计。数值结果验证了我们提出的基于联合多面板正交投影的信道估计优于现有方案的优越性。