Distributed Resource Allocation for Downlink Multicell OFDMA Systems

This paper addresses resource allocation for sum throughput maximization in a sectorized two-cell downlink OFDMA systems impaired by multicell interference. It is well known that the optimization problem for this scenario is NPhard and combinational, which is here converted to a novel sum throughput maximization problem based on the intercell interference limitation. Then, two subclasses of this new problem are solved. By the first subclass, on the assumption that subcarrier allocation parameters are fixed, an algorithm for optimal power allocation is obtained. By the second subclass, the problem is reduced to a single cell case where the intercell interference in each subcarrier is limited to a certain threshold. The solution shows that the subcarrier allocation can be performed prior to power distribution. Based on the solution of the single cell problem, a distributed resource allocation scheme with the aim of small information exchange between the coordinated base stations is proposed. KeywordsDual method, multicell resource allocation, OFDMA, interference limitation, convex optimization,