Three-dimensional coverage control of common control signals for coverage holes elimination and interference suppression

A new demand of three-dimensional (3D) coverage of wireless signals is arising, since the wireless traffics are gradually distributed in 3D space in the processes of urbanization and high-rise building´s popularization. In this paper, 3D coverage control technology based on planar array antenna and 3D beamforming is investigated, and a novel control algorithm HEIS is proposed. Starting from the key performance metrics, i.e., weak coverage ratio (WCR), interference level (IL) and transmission power, an optimization model is established to minimize the transmission power with the constraints of zero WCR and zero IL. Semi-definite relaxation, randomization and compensation adjustment are adopted step by step to obtain suboptimal excitation weights for feeding planar array antenna. It is validated through simulation that the proposed HEIS algorithm outperforms the antenna power-downtilt joint adjustment method in coverage hole elimination, inter-cell interference suppression and energy saving obviously.