Sparse Precoding in Multicell MIMO Systems

In this paper, the authors consider the joint precoding across K distant Transmitters (TXs) towards K single-antenna Receivers (RXs) and they let the TXs have access to perfect Channel State Information (CSI). Instead of considering the conventional method of clustering to allocate the user's data symbols, they focus on determining the most efficient symbol sharing patterns. Consequently, they optimize directly the user's data symbol allocation subject to a constraint on the total number of user's data bits transmitted through the core network. They develop a novel approach whereby sparse precoders approximating the true precoders are computed.