Performance analysis of user-centric SBS deployment with load balancing in heterogeneous cellular networks: A Thomas cluster process approach

Abstract

In conventional heterogeneous cellular networks (HCNets), the locations of user equipments (UEs) and base stations (BSs) are modeled randomly using two different homogeneous Poisson point processes (PPPs). However, this might not be a suitable assumption in case of UE distribution because UE density is not uniform everywhere in HCNets. Keeping in view the existence of nonuniform UEs, the small base stations (SBSs) are assumed to be deployed in the areas with high UE density, which results in correlation between UEs and BS locations. In this paper, we analyse the performance of HCNets with nonuniform UE deployment containing a union of clustered and uniform UE sets. The clustered UEs are considered to be modeled according to Thomas cluster process, and random UEs are assumed to be deployed via homogeneous PPP. The SBSs are considered to be deployed at the center of the UE clusters, which results in user-centric SBS deployment. We derive outage probability and rate coverage of the proposed model. Furthermore, to improve the network performance, the impact of association biasing is also assumed. Our results show that the user-centric SBS deployment outperforms the conventional HCNets model. Increase in association bias upto a certain value results in performance improvement of the proposed user-centric HCNet.