Joint distributed cell association and interference management in OFDMA‐based heterogeneous networks

Abstract

AbstractConsidering the ever‐growing demand for network traffic, increasing the capacity of cellular networks has always been a necessity. Heterogeneous cellular networks using small‐scale base stations in addition to macro base stations (BSs) are a low cost and effective solution to this problem. The diversity of the BSs in heterogeneous networks, however, has raised new issues in terms of cell association and interference management compared with the traditional single‐tier networks. Devising novel and effective methods for cell association and resource allocation in these networks is currently an open and developing problem. This paper addresses cell and subband association in the downlink of orthogonal frequency‐division multiple‐access heterogeneous networks. Unlike the existing works in this field, our scheme maximizes network utility while preventing harmful interference for all connections in the network. Using the protocol interference model, necessary and sufficient constraints for preventing interference in cellular networks are presented. By choosing the appropriate interference constraint, the joint problem of cell and subband association is formulated as an integer optimization problem. After simplifying the optimization problem, an equivalent linear problem is obtained. Using one‐level dual decomposition, an iterative algorithm with a near‐optimal solution has been devised. A distributed protocol is then presented, in which each user and each BS requires only its own local data to determine its connection for service. The simulation results demonstrate the algorithm behavior and confirm the efficiency and near‐optimality of the proposed solution.