Power control and beamforming in two-tier femtocell networks

Femtocells are cellular home base station which provides better cellular coverage and capacity. It features are low power, short range and low cost. Femtocells are installed in existing macrocellular networks which forms a two-tiered heterogeneous network that yields an interference problem between the two layers. The interference can be mitigated using power control and beamforming for two-tier femtocells networks with the presence of channel uncertainty condition such as channel estimation, quantization, and feedback delay [4]. The transmit power control provides desired signal-to-interference-plus-noise ratio (SINR) to the indoor cell edge femtouser and beamforming provides beam weight to maximize the output SINR of macrousers and femtousers.