Research On The Performance Of WCDMA System Deployed By Femtocells

Femtocell, also called as Home NodeB, is an ultra-small mobile station that is newly brought forward based on the development of 3G and trend of mobile broadband. Different from microcell and picocell, only the air interface part of Femtocell is corresponding to 2G or 3G standards. Femtocell doesn't connect with mobile operators'core network directly. Femtocell would connect to a home router/modem, such as ADSL, Cable Modem, and traffic would be backhauled over IP via Ethernet and then be converged by Femtocell gateway at the side of operators' core network. The character of Femtocell enables it to provide fast, low-cost 3G indoor coverage for households. In addition, the size of Femtocell is the same as ADSL or Wi-Fi Modem, and Femtocell also has the characteristics of convenient installment, self-configuration and self network planning and plug-and-play. Those characteristics help the deployment of Femtocell.Although Femtocell would be attractive to both consumers and operators, there are still several problems need to be solved when Femtocell are actually deployed in a large scale, such as the cost of Femtocell, the management of Radio Frequency, Mobile station's handover, network timing and synchronization and QoS Guarantee of backhaul, etc.In this paper, we analyze the impact of Femtocell deployment to WCDMA system network performance from a theoretical point of view and built a simulation model on system level using Matlab simulation tool under the WCDMA system based on 3GPP related protocols and other inference papers. First, we analyze the impact of Femtocell deployment to WCDMA Macro cell call blocking rate. In aspect of improving wireless resource management algorithm, this paper propose three reducing unnecessary handover algorithms, changing handover conditions to form unequal handover, based on the velocity of mobile station to perform handover and using adaptive pilot power control algorithm. Finally, those algorithms are verified by our simulation model, and it works well.