A novel interference avoidance scheme based on blind polarization signal processing for cognitive Femtocell network

Femtocell technology has been recently proposed as a potential solution to improve spectrum efficiency. However, serious interference problem has also been brought in as well as the benefits. In this paper, a novel interference avoidance scheme based on blind polarization signal processing for cognitive Femtocell network is proposed. Femtocell network uses the polarization state which is orthogonal to the macrocell user (MUE) so as to avoid the interference to MUE. Cognitive Femtocell base station (FBS) obtains information from MUE firstly and then obtains polarization state for the whole Femtocell network with blind polarization signal processing without any prior information of channel between FBS and MUE. Polarized noise suppression method is also included to mitigate the random interference from additive white Gaussian noise to the arrived signal at FBS. Numerical simulation results show that the scheme can perform well under flat Rayleigh-fading channel.