A Co-Channel Interference Rejection Method for 5G Ultra Dense Heterogeneous Networks

Ultra dense heterogeneous networks (UDHN) is one of the leading ideas in fifth generation (5G) mobile communication systems to improve the spectrum efficiency and the energy efficiency. In future 5G systems, users will be able to use the diverse radio access technologies (RATs) simultaneously. However, one of crucial issues in spectral sharing 5G UDHN is the co-channel interference among the small cell base stations (SCBSs) in different networks, such as cellular and WiFi networks. In order to mitigate the co-channel interference in the receiver, a co-channel interference suppression method is proposed in this paper. In this method, the covariance matrix of the interference is first approximated by the difference between the covariance matrices of the received signal and the desired signal. Subsequently, diagonal loading is adopted to generate the estimated covariance matrix of the interference to improve the robustness of the method. Simulation results are presented to demonstrate the advantage of the proposed algorithm.