# Linear Algebraic Beamforming Design for Multiuser MISO Interference Channels: A Reduction in Search Space Dimension

^{1}

ICT Convergence Research Team, Korea Railroad Research Institute, Eiwang 16105, Korea

^{2}

Department of Computer Science and Engineering, Dankook University, Yongin 16890, Korea

^{3}

Department of Electronics Engineering, Sookmyung Women’s University, Seoul 04310, Korea

^{*}

Author to whom correspondence should be addressed.

Received: 27 April 2018 / Revised: 3 June 2018 / Accepted: 3 June 2018 / Published: 4 June 2018

(This article belongs to the Special Issue Information Theory and 5G Technologies)

Near-optimal transmit beamformers are designed for multiuser multiple-input single-output interference channels with slowly time-varying block fading. The main contribution of this article is to provide a method for deriving closed-form solutions to effective beamforming in both low and high signal-to-noise ratio regimes. The proposed method basically leverages side information obtained from the channel correlation between adjacent coding blocks. More specifically, our methodology is based on a linear algebraic approach, which is more efficient than the optimal scheme based on the Gaussian input in the sense of reducing the average number of search space dimensions for designing the near-optimal transmit beamformers. The proposed method is shown to exhibit near-optimal performance via computer simulations in terms of the average sum-rate.