Optimal deployment of pico base stations in LTE-Advanced heterogeneous networks

As data traffic demand in cellular networks grows exponentially, operators need to add new cell sites to keep up; unfortunately, it is costly to build and operate macrocells. Moreover, it may not be possible to obtain the needed approvals for additional macrocell sites. Recently, the 3rd Generation Partnership Project (3GPP) introduced the concept of heterogeneous networks in Long Term Evolution (LTE) Release 10, where low-power base stations (BSs) are deployed within the coverage area of a macrocell to carry traffic. However, this new type of deployment can cause more severe interference conditions than a macro-only system, due to inter-cell interference; hence, enhanced inter-cell interference coordination (eICIC) has been actively discussed in LTE Release 10. Nevertheless, eICIC cannot completely eliminate interference and, to make matters worse, high-power transmissions of the reference signals from the BSs may increase the interference level. In this paper, we propose an algorithm for deploying low-power nodes within macrocell coverage areas in LTE heterogeneous networks, which aims to increase the system utility while minimizing the installation cost.