Bon Tae Koo

Femtocell interference analysis based on the development of system-level LTE simulator

Although femtocell can confer various benefits to both operators and users, many technical issues, such as interference coordination, network synchronization, self-configuration, and self-optimization must be considered to effectively deploy femtocells in real environments. In this article, we develop a system-level simulator in order to evaluate performance of long-term evolution (LTE)-femtocell systems. The simulator consists of five functional modules which realize packet scheduling and call admission control functionalities and model various wireless channel effects, real and non-real time traffics, and user mobility. These modules are managed by operational modules that follow event-driven programming. In addition, the simulator adopts a graphical user interface (GUI) that facilitates configuration, management, and observation of simulations in real time. Based on the simulator, we analyze effects of signal interference between macro- and femtocells under four scenarios. From the results, we confirm that the developed LTE-femtocell simulator can effectively support performance evaluation and analysis on various femtocell deployment scenarios.

Victim macro UE detection procedure based on network assistance in LTE-femtocell networks

In long term evolution (LTE), home evolved node B (HeNB) has been introduced to improve indoor channel quality and take over indoor traffic from macro eNB (MeNB) at a low cost. As MeNB and HeNB share radio resources to obtain high capacity, victim macro user equipments (VMUEs) may exist due to severe interference from HeNB. For efficiently coordinating interference to the VMUEs, the HeNB should exactly perceive presence and absence of its neighboring VMUEs. In this paper, we propose a VMUE detection procedure based on network assistance in LTE-femtocell networks. By using the proposed detection procedure, HeNB can appropriately perform interference coordination (IC) as detection results of VMUE. Performance evaluations show the throughput of MUEs can be improved by combining the proposed procedure and IC.

Development of Femtocell Simulator Based on LTE Systems for Interference and Performance Evaluation

Recently, femtocell has been concerned as one of effective solutions to relieve shadow region and provide high quality services to users in indoor environments. Even though femtocell offers various benefits to cellular operators and users, many technical issues, such as interference coordination, network synchronization, self-configuration, self-optimization, and so on, should be solved to deploy the femtocell in current network. In this paper, we develop a simulator for evaluating performance of long term evolution (LTE) femtocell systems under various interference scenarios. The simulator consists of a main-module and five sub-modules. The main-module connects and manages five sub-modules which have the functionality managing user mobility, packet scheduling, call admission control, traffic generation, and modulation and coding scheme (MCS). To provide user convenience, the simulator adopts graphical user interface (GUI) which can observes simulation results in real time. We expect that this simulator can contribute to developing effective femtocell systems by supporting a tool for analyzing the effect of interference between macrocell and femtocell.