Fractional dynamic clustering in downlink cellular network

In modern cellular systems, to improve the spectral efficiency and the system capacity we use multiple base station (BS) cooperation in downlink cellular networks. This method can highly improve the transmission rate when the user is a cell-edge user. But when the user is a cell-center user, it has minimal improvement on the user capacity, and increases the complexity of the network. As the whole system BS cooperation is hardly achieved, grouping BSs into clusters can realize BSs cooperation. But it still suffers from inter-cluster interference especially for the cluster-edge users. In this paper we consider fractional base station cooperation to deal with the problem. The clusters are formed dynamically for the cell-edge users from the users´ perspective to reduce the inter-cluster interference, and are allowed to be overlapped. Accordingly, coordinated precoding scheme is adopted to reduce the intra-cluster interference. Simulations show that the proposed scheme provides impressive average capacity and the user fairness is improved significantly.