论文标题
零反馈FDD的大量MIMO系统中频域通道外推的实验研究
Experimental Investigation of Frequency Domain Channel Extrapolation in Massive MIMO Systems for Zero-Feedback FDD
论文作者
论文摘要
估算频划分双工（FDD）大量多输入多输出（MIMO）系统中的下行链路（DL）通道状态信息（CSI）通常需要下行链路飞行员和反馈开销。因此，本文研究了基于渠道外推的零反馈FDD大规模MIMO系统的可行性。我们使用高分辨率参数估计（HRPE），特别是基于上行链路通道中多径成分的提取参数来外推DL CSI。我们将HRPE应用于两个不同的通道模型：矢量空间签名（VSS）模型和到达方向（DOA）模型。我们通过使用两种不同类型的频道声音的通道测量活动获取的现实世界通道数据来验证这些方法：a）基于切换阵列的，实时的，实时的，时间域，户外设置为3.5 GHz，b）基于虚拟阵列的，基于虚拟阵列的，高阵列，频率频率，频率 - 频率，频率 - 范围，indoors，indoors in 2.4和5-7 ghz indoors设置。我们评估的推断通道的性能指标包括在多源MIMO场景中的平均误差，波束形成效率和光谱效率。结果表明，基于HRPE的通道外推在简单的VSS模型下表现最好，该模型不需要数组校准，如果BS在开放的室外环境中，则具有良好分离用户的视线（LOS）路径。
Estimating downlink (DL) channel state information (CSI) in frequency division duplex (FDD) massive multi-input multi-output (MIMO) systems generally requires downlink pilots and feedback overheads. Accordingly, this paper investigates the feasibility of zero-feedback FDD massive MIMO systems based on channel extrapolation. We use the high-resolution parameter estimation (HRPE), specifically the space-alternating generalized expectation-maximization (SAGE) algorithm, to extrapolate the DL CSI based on the extracted parameters of multipath components in the uplink channel. We apply the HRPE to two different channel models: the vector spatial signature (VSS) model and the direction of arrival (DOA) model. We verify these methods through real-world channel data acquired from channel measurement campaigns with two different types of channel sounders: a) a switched array-based, real-time, time-domain, outdoors setup at 3.5 GHz, and b) a virtual array-based, high-accuracy, frequency-domain, indoors setup at 2.4 and 5-7 GHz. The performance metrics of the extrapolated channels that we evaluate include the mean squared error, beamforming efficiency, and spectral efficiency in multiuser MIMO scenarios. The results show that the HRPE-based channel extrapolation performs best under the simple VSS model, which does not require array calibration, and if the BS is in an open outdoor environment having line-of-sight (LOS) paths to well-separated users.
