Frequency resource allocation strategy with QoS support in hybrid cellular and Device-to-Device networks.

Hybrid networks, comprising a conventional cellular network overlaid with Device-to-Device (D2D), offer efficient way to improve system throughput. In this paper, a novel orthogonal frequency-division multiple access channel-assignment method is proposed for hybrid network. The proposed approach is optimal in terms of throughput and is subjected to a sensible QoS requirement, which guarantees that macrocell and D2D achieve a prescribed data rate and outage probability, respectively. Our solution consists of two phases. In the first phase, the minimum sub-channels are allocated to the macrocell to satisfy their data rate requirements. This problem is mapped to the 0-1 Knapsack Problem and solved by integer programming based Lagrange dual approach. In the second phase, the redundant sub-channels are allocated to D2D pairs to maximize the throughput of D2D networks. An interference management scheme is proposed to guarantee the outage probability of D2D communications. A cluster is taken as the unit for frequency reuse among D2D pairs. The problem of clustering is mapped to the MAX k-CUT problem in graph theory and is solved by graph-based heuristic algorithm. Extensive simulations demonstrate the superior performance of the proposed solution compared with the existing scheme. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]