Joint Power Control, Base Station Assignment, and Channel Assignment in Cognitive Femtocell Networks

Johnpaulm Torregoza,Rentsen Enkhbat,Won-Joo Hwang

doi:10.1155/2010/285714

Abstract

Cognitive radio and femtocells are recent technology breakthroughs that aim to achieve throughput improvement by means of spectrum management and interference mitigation, respectively. However, these technologies are limited by the former's susceptibility to interference and the latter's dependence on bandwidth availability. In this paper, we overcome these limitations by integrating cognitive radio and femtocell technology and exploring its feasibility and throughput improvement. To realize this, we propose an integrated architecture and formulate a multiobjective optimization problem with mixed integer variables for the joint power control, base station assignment, and channel assignment scheme. In order to find a pareto optimal solution, a weighted sum approach was used. Based on numerical results, the optimization framework is found to be both stable and converging. Simulation studies further show that the proposed architecture and optimization framework improve the aggregate throughput as the client population rises, hence confirming the successful and beneficial integration of these technologies.

Highlights

Regulatory bodies throughout the world have found that communication bandwidth is becoming scarce, with two of the major causes being inefficient use of the spectrum and ineffective interference mitigation [1]
Studies have found that the majority of the spectrum bands, the licensed bands, are inefficiently utilized
(iii) we provided numerical and simulation results to show that the proposed joint power control, base station assignment, and channel assignment scheme for cognitive femtocell networks achieves better performance than conventional architectures (Section 4)

Summary

Introduction

Regulatory bodies throughout the world have found that communication bandwidth is becoming scarce, with two of the major causes being inefficient use of the spectrum and ineffective interference mitigation [1]. Studies have found that the majority of the spectrum bands, the licensed bands, are inefficiently utilized. Cellular and ISM bands are overloaded in most parts of the world while UHF TV and amateur radio bands are underutilized in some locations at some specific time instances [2, 3]. In accordance with this, increasing interference levels in the overloaded spectrum render interference mitigation schemes ineffective. We make use of cognitive radio and femtocell technology to resolve inefficient spectrum utilization and high levels of interference, respectively

Objectives

Findings

Discussion

Conclusion