Coherent Sub-channel Based CSI Reconstruction for Wideband Massive MIMO Systems

Abstract

Frequency division duplex (FDD) massive multiple-input multiple-output (MIMO) systems require a large amount of channel state information (CSI) feedback from each user in the uplink (UL), which result in huge overhead. This brings great challenges. To tackle this, we study the relationship of CSI between two different frequency bands, and propose a novel coherent sub-channel based CSI reconstruction (CSBCR) scheme utilizing the correlation of CSI in different frequency bands. Our scheme can reconstruct the downlink (DL) CSI depending on the UL CSI without any feedback from users. The simulation results suggest that the proposed scheme achieves an improved performance compared with other previous works. Besides, our scheme can be employed in any system where the CSI can be obtained through the CSI of another frequency band even if the frequency interval is large.