Browsing by Author "Wang, Jing-Wen"

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Reconfigurable Hybrid Beamforming for Dual-Polarized mmWave MIMO Channels
(2016)
Wu, Sau-Hsuan
;
Wang, Jing-Wen
;
Chen, Ju-Ya
;
電機工程學系
;
Department of Electrical and Computer Engineering
A reconfigurable hybrid beamforming (HBF) system is proposed to flexibly exploit the channel diversities and antenna array directivity in millimeter wave channels. Sub-arrays of antennas can be reconfigured in the proposed HBF system to adjust the spatial and polarization diversities and the array gains according to the channel environments and the relative locations between the transmitter and the receiver. Based on the reconfigurable HBF system, a training procedure is also proposed for the transmitter and the receiver to learn the best operating mode according to channel quality and characteristics. Compared to a fixed HBF system, the reconfigurable HBF system has 3 to 10 dB power gains in channel capacity in various simulated channel conditions.
Reconfigurable Hybrid Beamforming for Dual-Polarized mmWave MIMO Channels: Stochastic Channel Modeling and Architectural Adaptation Methods
(2018-02-01)
Wu, Sau-Hsuan
;
Chiu, Lin-Kai
;
Wang, Jing-Wen
;
電機工程學系
;
Department of Electrical and Computer Engineering
A reconfigurable hybrid beamforming (HBF) system is presented to dynamically exploit the channel diversities and antenna array directivity in millimeter wave (mmWave) channels. To develop an effective method for HBF architecture adaptation in wideband mmWave channels, the performance of an architecture is evaluated based on its average frequency-domain channel capacity. According to our analysis and simulations, the spatial covariance of the frequency-domain channels of using HBF can still be approximately modeled in a Kronecker form. Furthermore, beamforming directivity and channel spatial diversity have different advantages on capacity improvement in different transceiving conditions. Based on the results of channel modeling, system analysis, and simulations, a reconfigurable HBF architecture is thus proposed to enable flexible adjustments of the active subarrays, the antennas and polarizations of each subarray, and the active analog front-end and radio frequency chains linked to the active subarrays. A training procedure is meanwhile developed for the HBF system to learn proper architectures according to the system constraints, the channel statistics, the baseband precoder structure, and the channel capacity between the transmitter and the receiver. Compared with a fixed HBF system, such a reconfigurable system provides 3-15-dB power gains in channel capacity under various simulated channel conditions.