Area Spectral Efficiency Of The Heterogenoeous Cellular Networks

The contradiction between the scarcity of available radio spectrum resources and the growing demand of spectrum resources for wireless communication systems is sharpening.Thus spectrum resources become one of the paramount considerations in the future wireless communication systems.As one of the most promising and low-cost approaches to improve the system capacity of mobile networks,heterogeneous cellular networks(HCNs)architecture is an attractive means for researchers.This study analyzes spectral efficiency of a macro-only cellular network,a two-tier HCN consisting of macrocell base stations(BSs)and picocell BSs and a HCN consisting of WLAN stations and macrocell BSs.Area spectral efficiency(ASE)is taken as the performance metric of spectral efficiency,which is an important performance metric for cellular networks and studied under simple regular grid models.While the study of heterogeneous cellular networks is usually based on the stochastic geometry models,since BSs of each tier are randomly distributed with different power levels.Through both regular grid models and stochastic geometry models,the uplink and downlink ASE metric in the above networks are investigated in this study.Aiming at providing a tractable model and method to better characterize the performance of HCNs,the ASE metric of the above networks is evaluated both through theoretical derivations and numeric simulations.Comparing the analysis results of uplink and downlink ASE of a macro-only network by regular grid models and stochastic geometry models,we can find that the two models have the same change laws on most of the relevant parameters with minor differences in the numerical size.The comparison results of the macro-only network and the two-tier HCN indicate that,the ASE results of the two-tier HCN can be increased more than 2 times,when setting appropriate parameters.Similarly,the ASE results of a HCN consisting of WLAN stations and macrocell BSs grow fivefold,when the conflict among users is under control.