Joint Downlink Base Station Association and Power Control for Max-Min Fairness: Computation and Complexity

• Published in: IEEE journal on selected areas in communications Vol. 33; no. 6; pp. 1040 - 1054
• Main Authors: Sun, Ruoyu, Hong, Mingyi, Luo, Zhi-Quan
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2015; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Channels; Computation; Downlink; Gain; Interference; Joints; Networks; Operations research; Power control; Resource management; Transformations; Uplink; Upper bound; polynomial time solvable; distributed algorithm; power control; Base station association; downlink interference channel
• ISSN: 0733-8716; 1558-0008
• DOI: 10.1109/JSAC.2015.2416982

In a heterogeneous network (HetNet) with a large number of low power base stations (BSs), proper user-BS association and power control is crucial to achieving desirable system performance. In this paper, we systematically study the joint BS association and power allocation problem for a downlink cellular network under the max-min fairness criterion. First, we show that this problem is NP-hard. Second, we show that the upper bound of the optimal value can be easily computed, and propose a two-stage algorithm to find a high-quality suboptimal solution. Simulation results show that the proposed algorithm is near-optimal in the high-SNR regime. Third, we show that the problem under some additional mild assumptions can be solved to global optima in polynomial time by a semi-distributed algorithm. This result is based on a transformation of the original problem to an assignment problem with gains log(g ij ), where {g ij } are the channel gains.