Decentralized user association for (p, α)-proportional fair-based system throughput maximization in cellular networks

This paper proposes a new user association method to maximize the downlink system throughput in a cellular network, where the system throughput is defined based on (p, α)-proportional fairness. The proposed method assumes a fully decentralized approach, which is practical in a real system as complicated inter-base station (BS) cooperation is not required. In the proposed method, each BS periodically and individually broadcasts supplemental information regarding the bandwidth allocation to newly connected users. Assisted by this information, each user calculates the expected throughput that will be obtained by connecting the respective BSs. Each user terminal feeds back the metric for user association to the temporally best BS, which represents a relative increase in throughput through re-association to that BS. Based on the reported metrics from multiple users, each BS individually updates the user association. The proposed method is especially effective in heterogeneous cellular networks where low transmission-power pico BSs are overlaid onto a high transmission-power macro BS for traffic offloading. Computer simulation results show that the proposed method maximizes the system throughput from the viewpoint of the given (p, α)-proportional fairness.