论文标题
宽带FDD大型MIMO的部分频道基于互惠的代码手册
A Partial Channel Reciprocity-based Codebook for Wideband FDD Massive MIMO
论文作者
论文摘要
在频分化双工（FDD）中获取通道状态信息（CSI）是一个巨大的挑战。在本文中，我们通过宽带制度中上行链路和下行链路频道的部分互惠来实现新颖的CSI反馈框架来解决这个问题。我们首先得出宽带大规模MIMO通道协方差矩阵的封闭形式表达，以给定的角度延迟分布。鉴定出低级别的特性，该特性概述了窄带均匀线性阵列设置的众所周知的结果。然后，我们提出了一个部分通道互惠（PCR）代码手册，灵感来自低级别行为以及上行链路和下行链路通道具有相似的Angle-delay分布的事实。与5G中最新的代码簿相比，提议的PCR代码书方案可实现更高的性能，在用户方面较低的复杂性，并且需要较少的反馈。我们得出所需的反馈开销，以实现渐近无错误的CSI反馈。还提出了两种低复杂性替代方案，以进一步降低基站侧的复杂性。使用实用3GPP频道模型的模拟显示了最新的5G代码手册的显着增长，这证明我们提出的方法是5G及以后的实用解决方案。
The acquisition of channel state information (CSI) in Frequency Division Duplex (FDD) massive MIMO has been a formidable challenge. In this paper, we address this problem with a novel CSI feedback framework enabled by the partial reciprocity of uplink and downlink channels in the wideband regime. We first derive the closed-form expression of the rank of the wideband massive MIMO channel covariance matrix for a given angle-delay distribution. A low-rankness property is identified, which generalizes the well-known result of the narrow-band uniform linear array setting. Then we propose a partial channel reciprocity (PCR) codebook, inspired by the low-rankness behavior and the fact that the uplink and downlink channels have similar angle-delay distributions. Compared to the latest codebook in 5G, the proposed PCR codebook scheme achieves higher performance, lower complexity at the user side, and requires a smaller amount of feedback. We derive the feedback overhead necessary to achieve asymptotically error-free CSI feedback. Two low-complexity alternatives are also proposed to further reduce the complexity at the base station side. Simulations with the practical 3GPP channel model show the significant gains over the latest 5G codebook, which prove that our proposed methods are practical solutions for 5G and beyond.
