Improved power control for femtocells in the presence of channel uncertainty

A wireless network increases its system capacity by keeping the transmitter and the receiver nearer to one another which rapidly increases the spatial reuse technique and provides better QoS. The nomadic users in the network deploys high infrastructure usually in the form of picocells, microcells, hotspots, etc. A new alternative concept involving fewer infrastructures is the deployment of home base station known as femtocells. These femtocells are small, low power cellular base station which are installed at home or small business enterprises with the help of internet connection. In this paper, two-tier heterogeneous networks are formed by installing femtocells with the macrocellular networks that creates an interference problem between them. By examining the performance of the system with imperfect channel state information associated with channel estimation, feedback delay and quantisation error, we obtain the improved power control level for femtocells and null interference using beam generation. In order to mitigate the interference, we propose a method of improving the power control for femtocells and beamforming to maximise the macrouser and femtouser SINR. Simulation results are analysed using NS-2 software.