  To cope with the ever increasing demand for bandwidth, future wireless
networks will be designed with reuse distance equal to one. This scenario
requires the implementation of techniques able to manage the strong multiple
access interference each cell generates towards its neighbor cells. In
particular, low complexity and reduced feedback are important requirements for
practical algorithms. In this paper we study an allocation problem for OFDMA
networks formulated with the objective of minimizing the load of each cell in
the system subject to the constraint that each user meets its target rate. We
decompose resource allocation into two sub-problems: channel allocation under
deterministic power assignment and continuous power assignment optimization.
Channel allocation is formulated as the problem of finding the maximum weighted
independent set (MWIS) in graph theory. In addition, we propose a minimal
weighted-degree greedy (MWDG) algorithm of which the approximation factor is
analyzed. For power allocation, an iterative power reassignment algorithm
(DPRA) is proposed. The control information requested to perform the allocation
is limited and the computational burden is shared between the base station and
the user equipments. Simulations have been carried out under constant bit rate
traffic model and the results have been compared with other allocation schemes
of similar complexity. MWDG has excellent performance and outperforms all other
techniques.
