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- 摘要
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- 实验方案
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[IEEE 2019 16th China International Forum on Solid State Lighting & 2019 International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - Shenzhen, China (2019.11.25-2019.11.27)] 2019 16th China International Forum on Solid State Lighting & 2019 International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - Thermal Simulations of a UV LED module with nanosilver sintered die attach process on graphene-coated copper substrates
摘要： Massive multiple-input multiple-output is a promising physical layer technology for 5G wireless communications due to its capability of high spectrum and energy efficiency, high spatial resolution, and simple transceiver design. To embrace its potential gains, the acquisition of channel state information is crucial, which unfortunately faces a number of challenges, such as the uplink pilot contamination, the overhead of downlink training and feedback, and the computational complexity. In order to reduce the effective channel dimensions, researchers have been investigating the low-rank (sparse) properties of channel environments from different viewpoints. This paper then provides a general overview of the current low-rank channel estimation approaches, including their basic assumptions, key results, as well as pros and cons on addressing the aforementioned tricky challenges. Comparisons among all these methods are provided for better understanding and some future research prospects for these low-rank approaches are also forecasted.
关键词： angle reciprocity,low-rank property,Massive MIMO,channel sparsity,channel estimation
更新于2025-09-19 17:13:59
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Beam-Time Block Coding With Joint User Grouping and Beamforming for FDD Massive MIMO Systems
摘要： A downlink (DL) precoding scheme that needs no DL training nor uplink (UL) feedback for massive MIMO systems operated under frequency-division duplex (FDD) is proposed, whereas most of the schemes in the literature were proposed to compress the overhead of training and feedback. Due to the above advantage, the proposed scheme is suitable for extremely low-latency applications. This scheme exploits angle reciprocity of FDD systems to enable the base station to acquire partial DL channel state information through a previous UL signaling. A joint user grouping and beamforming optimization method without DL training and UL feedback is proposed to enhance spectral efficiency and mitigate interference between multiple UEs during DL data transmission. Simulation results suggest that the proposed scheme possesses a comparable performance to a number of previous grouping-based schemes that require DL training and UL feedback.
关键词： angle reciprocity,no CSI feedback.,frequency-division duplex,Massive MIMO,beam-time block coding
更新于2025-09-10 09:29:36