CSI Feedback Allocation in Multicell MIMO Channels
In this paper, the authors consider the joint pre-coding across K Transmitters (TXs), sharing the knowledge of the user's data symbols being transmitted to K single-antenna Receivers (RXs). They consider a Distributed Channel State Information (DCSI) configuration where each TX has its own local estimate of the overall multiuser MIMO channel. Their focus is on the optimization of the allocation of the CSI feedback subject to a constraint on the total amount of feedback. As a starting point, they consider the Wyner model where they derive a distance-based CSI allocation achieving close to the optimal performance using only a small percentage of the total feedback.