Using beamforming for dense frequency reuse in 5G

Abstract

Implementing an efficient frequency reuse (FR) plan is significantly important to meet the demand on high data rates and the required quality of service for 5G. In this paper, we use the direction of arrival algorithms and the correlator to determine the directions of the desired user and the interferers in the cell. Then, we use the beamformer to produce a beam towards the desired user and nulls in the direction of the interferers. Moreover, we implement the synthesizer to smartly form the desired beam shape and make the nulls deeper. We take the advantage of the smart antennas, beamforming capabilities, and the radiation pattern synthesizing techniques to build up an efficient FR plan for 5G. In addition, we develop a formula for calculating the signal to interference and noise ratio (SINR) in terms of the desired and the interferers directions. Our objective is to maintain the SINR at the minimum levels required for data calls with accepted quality while reducing the beam sizes, and hence increase the FR factor. Our simulation results show that with a uniform linear antenna of 11 elements, we can achieve the desirable SINR levels using beams of 10° width, which raises the FR factor from 1 to 18 and subsequently increases the number of mobile users by 18 times.