CS/CB CoMP scheme with semi-static data traffic offloading in HetNets

Co-channel interference is considered as one of the most important issues limiting the performance of cellular systems. In LTE-A systems, the Coordinated Multi-Point (CoMP) transmission technology was introduced to effectively manage data traffic at the transmission nodes for reducing co-channel interference. CoMP transmission is realized by exchanging coordination information via backhaul links, typically available between the transmission nodes. However, in practical networks the backhaul links may have capacity constraints hindering the use of CoMP techniques with high-rate information exchange. In scenarios where ideal backhaul link is not available, coordinated scheduling and coordinated beamforming (CS/CB) CoMP schemes can be used. However, the conventional CS/CB CoMP scheme only assumes interference coordination between the transmission nodes which significantly limits the expected performance benefits that can be additionally achieved by using traffic management techniques. In this paper, we propose a CS/CB CoMP scheme with semi-static traffic offloading. Traffic management in the proposed scheme is achieved by using the cell range expansion concept that takes into consideration a limited set of the transmission points that can be simultaneously coordinated to reduce interference. For comparison, the LTE-A time-domain enhanced inter-cell interference coordination (eICIC) scheme with conventional cell range expansion is considered.