Performance evaluation of coordinated dual-cell transmission based on random unitary beamforming with user scheduling

In this paper, we present and study the performance of a coordinated random beamforming transmission strategy for dual-cell multiple-input single-output (MISO) systems. The strategy under consideration has low complexity as the coordinating base stations need to share only the indices of the qualified beamforming vectors. Focusing on single-user scheduling in each cell, we analyze exact sum-rate of the resulting system. Based on selected numerical examples, we develop important design guidelines for coordinated random beamforming schemes. We also consider an adaptive implementation approach of the proposed strategy where the number of qualified beamforming vectors are determined based on a certain predetermined threshold.