Uplink-Aided Downlink Channel Estimation for a High-Mobility Massive MIMO-OTFS System
Uplink-Aided Downlink Channel Estimation for a High-Mobility Massive MIMO-OTFS System
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DOI：
10.1109/globecom48099.2022.10001420
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发表时间：
2022-12
期刊：
影响因子：
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通讯作者：
Daidong Ying;Feng Ye;R. Hu;Y. Qian
中科院分区：
文献类型：
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作者：
Daidong Ying;Feng Ye;R. Hu;Y. Qian
大规模多输入多输出（MIMO）系统将极大地增强下一代无线通信的性能，高流动性用户。正交时频空间（OTFS）是用于高移动性大规模MIMO用例的有前途的技术。然而，MIMO-OTFS系统需要准确的下行链路信道信息以获得最佳性能。针对高移动性用户场景，研究了一种基于频分双工大规模MIMO-OTFS系统的上行辅助下行信道估计方案。由于高移动性，大多数现有的工作忽略了在信道估计过程期间延迟、多普勒和角度域中的变化。在这项工作中，我们分析了上行链路和下行链路信道之间的互易性，并推导出估计误差，由于在处理上行链路信道估计的延迟。仿真结果表明，在高移动性的大规模MIMO-OTFS系统中，上行链路信道可能会发生显著变化，给定合理的少量处理延迟。这种变化将导致下行链路信道估计中的高误差。通过概念验证，我们未来的工作将集中在改进信道估计框架，减少处理延迟。
The massive multi-input-multi-output (MIMO) system will greatly enhance the performance of the next-generation wireless communications for many applications e.g., high-mobility users. The orthogonal time frequency space (OTFS) is a promising technique for high-mobility massive MIMO use cases. However, the MIMO-OTFS system requires accurate downlink channel information for optimal performance. This paper studies an uplink-aided downlink channel estimation scheme targeting high-mobility user scenario based on a frequency division duplex massive MIMO-OTFS system. Most of the existing work over-looks the change in the delay, Doppler, and angle domain during a channel estimation process due to high mobility. In this work, we analyze the reciprocity between an uplink and a downlink channel and derive the estimation error due to the latency in processing the uplink channel estimates. Simulation results demonstrate that an uplink channel may change significantly in a high-mobility massive MIMO-OTFS system, given a reasonably small amount of processing latency. Such a change will lead to high error in downlink channel estimation. With the proof of concept, our future work will focus on refining the channel estimation framework with a reduction of the processing latency.