Cell-Cluster Based Traffic Load Balancing in Cooperative Cellular Networks

Cooperative relaying is accepted as a promising solution to achieve high data rates over large areas in the future 4G wireless system. In this paper, a cell-cluster based traffic load balancing strategy is proposed to solve the problem of cell congestion in cooperative cellular networks. In the paper, a dynamic cell-cluster construction method is first studied based on the traffic distribution among the hot spot cell and its neighboring cells, which is followed by the calculation of transferred traffic from the hot spot cell to each of the noncongested cells in the cell-cluster in order to minimize the average blocking probability, then, after the study of spectral efficiency for both direct and cooperative relaying transmissions, a mathematic model is formulated to jointly optimize routing and radio resource allocation in traffic load balancing, and a greedy based CJRR (cell-cluster based joint routing and radio resource allocation) algorithm is proposed to find a suboptimal solution. Simulation results show that our proposed traffic load balancing strategy has a satisfying performance in system spectral efficiency and blocking probability comparing with other transmission schemes.