Inter-beam Interface Cancellation by 3d Polarized Beamforming in Power domain NOMA Systems

Abstract

The application of beamforming (BF) techniques in power domain non-orthogonal multiple access (NOMA) schemes allows users to share the same single BF vector for operational reliability. The occurrence of inter-beam interference (IBI) is highly probable in a congested cell (i.e., a cell with high user density and active users). IBI cancellation by using 3D polarized BF in order to enhance the practicability of NOMA systems is the focus of this thesis. An IBI cancellation scheme is proposed and evaluations of the spectrum efficiency according to the scenario congestion, as well as of the interference reduction by narrowing the generated beam to a desired beam-width, are presented.