Interference Coordination through Network-Synchronized Cyclic Beamforming

Abstract

The next generation of wireless networks (e.g.,) will use multiple techniques to improve channel spectral efficiencies. In this paper we focus on one such technique, beamforming, in the downlink channel. In each sector, a number of fixed beams are used to serve UEs (User Equipment). For each subband in each frame, the scheduler chooses a beam and then schedules one or more UEs within the corresponding beam. Since the power is focused on a narrow beam then the served UEs can achieve higher rates and the sector coverage is also increased. However, this beam causes more interference in adjacent sectors (flashlight effect). The neighboring sectors must therefore schedule UEs outside of the beam or at least know of the interference that will be experienced. In this paper we follow the second approach and assume no coordination among sectors except for the fact that they all use the same beam cycle period but this can be changed occasionally.