Low-Complexity Coordinated Beamforming Transmission for Multiuser MISO Systems and Its Performance Analysis

In this paper, we present a low-complexity coordinated beamforming transmission scheme for multiuser multiple-input-single-output (MISO) systems. With a minimum overhead signaling, the proposed scheme selects the beamforming vector and users while considering the interference from other cells. We develop the exact analytical expressions of the ergodic sum-rate for the resulting system for dual-cell scenario. Based on the analytical results, we compare the performance of the proposed scheme with other MISO transmission schemes in multiple cell environment, and then analyze their respective superiority and shortcomings. We show through selected numerical examples that our proposed coordinated beamforming scheme achieves tremendous performance gain over conventional schemes while only requiring beam index sharing between base stations.