Institute of Electrical & Electronic Engineers
Resource management to minimize energy consumption, such as by sub-channel (subcarrier or sub-band) allocation and power assignment (or rate control), has been actively studied. The authors consider an Orthogonal Frequency Division Multiple Access (OFDMA) system supporting M users with N resource blocks. Each block consists of one or multiple subcarriers. Since the problem of allocating N resource blocks to M users is generally NP-hard, various heuristic resource allocation algorithms have been considered with a greedy search to achieve polynomial complexity. A loose gap, however, from the optimum has been observed with the greedy-based algorithms.