Scheduling-assisted joint processing for CoMP in the framework of the WINNER+ project

The goal of this paper is to present the main achievements reached within the WINNER+ project concerning, in particular, clustering as a way to improve the feasibility of joint processing schemes as enablers of coordinated multipoint solutions. Three different approaches are presented. First, a single and static cluster of base stations is considered. In this case, a user-centric partial joint processing scheme is proposed to reduce with respect to a fully centralized approach both the inter-base information exchange and feedback from the users. Second, a dynamic and network-centric clustering approach is presented. It is shown that substantial gains can be obtained with respect to a static clustering scenario when a central unit jointly creates the clusters of collaborating base stations, schedules the users in these clusters and calculates the beamforming coefficients and the power allocation. Finally, a dynamic clustering technique is combined with multi-antenna receivers. In addition, a concept for a scalable channel state information feedback is also presented.