Feedback scheines for dynamic cooperation among multiple transmission points in LTE-Advanced Networks

An interference coordination technique by dynamic multi-point cooperation commonly referred as CoMP (coordinated multiple point transmission/reception) is one of the main topics currently being developed in the wireless communication industry. In 3GPP LTE-Advanced Release 11, a new work item on CoMP was initiated in September 2011 with the objective of providing the necessary specificatio support in the physical layer as well as in the higher layers. An important issue for the support of CoMP in LTE-A is how to design the CSI (channel status information) feedback to convey the downlink channel status of multiple coordinating transmission points. In this paper, we start by discussing the baseline feedback scheme to realize various CoMP transmission techniques in LTE-A. In addition, we discuss more advanced feedback schemes that focus in reducing the uplink overhead for CoMP while maintaing the downlink coordination performance. The benefit of such advanced feedback schemes are confirme by numerical results through system-level evaluations compliant with LTE-A evaluation methodology.