Optimal Resource Allocation for Uplink OFDMA in 802.11ax Networks
In this paper, we address the scheduling and resource allocation problem for uplink OFDMA in IEEE 802.11ax WLANs. The OFDMA resource allocation problem for 802.11ax is inherently difficult to solve because consecutive subcarriers are grouped into resource units, and each user is assigned to one resource unit at most. However, since power in the uplink is allocated to each user individually, the instantaneous utility maximisation problem can be formulated as an assignment problem, and hence, solved in polynomial time by the Hungarian algorithm. In order to provide long-term performance guarantees, we propose stochastic utility maximisation subject to both peak and average power constraints and solve the problem using Lyapunov optimisation. To the best of our knowledge, this is the first work that provides a stochastic resource allocation framework for uplink OFDMA in 802.11ax networks.
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