Hierarchical Resource Allocation in Femtocell Networks using Graph Algorithms

TL;DR

This paper introduces a hierarchical, graph-based resource allocation method for LTE femtocell networks that reduces complexity and interference, improving efficiency in interference management.

Contribution

A novel three-stage hierarchical resource allocation algorithm for femtocell networks that minimizes interference and reduces computational complexity.

Findings

Effective interference reduction demonstrated in LTE-based simulations

Significant decrease in computational complexity compared to optimal solutions

Algorithm utilizes existing network information for practical implementation

Abstract

This paper presents a hierarchical approach to resource allocation in open-access femtocell networks. The major challenge in femtocell networks is interference management which in our system, based on the Long Term Evolution (LTE) standard, translates to which user should be allocated which physical resource block (or fraction thereof) from which femtocell access point (FAP). The globally optimal solution requires integer programming and is mathematically intractable. We propose a hierarchical three-stage solution: first, the load of each FAP is estimated considering the number of users connected to the FAP, their average channel gain and required data rates. Second, based on each FAP's load, the physical resource blocks (PRBs) are allocated to FAPs in a manner that minimizes the interference by coloring the modified interference graph. Finally, the resource allocation is performed at each FAP considering users' instantaneous channel gain. The two major advantages of this suboptimal approach are the significantly reduced computation complexity and the fact that the proposed algorithm only uses information that is already likely to be available at the nodes executing the relevant optimization step. The performance of the proposed solution is evaluated in networks based on the LTE standard.