TY - JOUR Y1 - 2019/06// N2 - In this paper, we propose a novel scheme to reconstruct the downlink channel of a frequency-division-duplex (FDD) multi-antenna system utilizing uplink channel state information (CSI) combined with limited feedback. Our finding is that spatial reciprocity holds among frequency-independent parameters, including the gain, delay and angle of each propagation path in a wireless channel. Based on this, we first introduce the Newtonized orthogonal matching pursuit (NOMP) algorithm to estimate these frequency-independent parameters during uplink sounding. The gains are then refined through downlink training and sent back to the base station (BS). With only a limited amount of overhead, the refinement is able to improve the accuracy of downlink channel reconstruction substantially. Utilizing the uplink-estimated delays and angles and the downlink-refined gains, the BS can reconstruct the downlink channel from the uplink estimation. We carry out both simulations and over-the-air tests to assess the performance of the proposed downlink channel reconstruction scheme. Results demonstrate that the proposed scheme is promising. JF - IEEE Transactions on Wireless Communications N1 - This version is the author accepted manuscript. For information on re-use, please refer to the publisher?s terms and conditions. ID - discovery10077918 VL - 18 UR - https://doi.org/10.1109/TWC.2019.2911497 PB - IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC TI - Efficient Downlink Channel Reconstruction for FDD Multi-Antenna Systems AV - public A1 - Han, Y A1 - Hsu, T-H A1 - Wen, C-K A1 - Wong, K-K A1 - Jin, S SP - 3161 SN - 1558-2248 EP - 3176 IS - 6 KW - MIMO antenna system KW - frequency division duplex KW - downlink channel reconstruction KW - over-the-air test. ER -