Cooperative Spatial Multiplexing with Hybrid Channel Knowledge

Abstract

We explore the concept of cooperative spatial multiplexing for use in MIMO multicell networks. One key application of this is the transmission of possibly correlated symbol streams jointly by several multiple-antenna access points toward multiple single antenna user terminals located in neighboring cells. To augment the realism of this setting, we consider different levels of channel state information at the transmitter (CSIT). In one case, we further introduce a constraint on hybrid channel state information (HCSI) in which any given transmitter knows its own CSI perfectly while it only has statistical information about other transmitters' channels. This yield a game situation in which each cooperating transmitter makes a guess about the behavior of the other transmitter. We show different transmission strategies under this setting and compare them with fully cooperative (full CSI) and non cooperative schemes. Our results show a substantial cooperation gain despite the lack of instantaneous information