Schedule algorithm for mitigating inter-cell interference based on orthogonal complement space

Abstract

In order to avoid severe performance degradation led by the inter-cell interference (ICI) in orthogonal frequency division multiple access (OFDMA) systems with a frequency reused factor (FRF) of 1, distributed schedule algorithm (DS-OCS) and distributed proportional fairness schedule algorithm (DPFS-OCS) based on orthogonal complement space (OCS) were proposed. The first right and left singular vectors of the channel that the user experienced were selected as the transmitting and receiving beamforming vectors. An interference space was spanned by the left singular vectors of the entire interference users in the same channel. The most suitable user lay in the OCS of the interference space was scheduled to avoid suffering interference from neighboring cells based on the criterion of system capacity maximizing and proportional fairness. The simulation results show that the average system capacity can be improved by 2%–4% compared with the DS-OCS algorithm with the Max C/I algorithm, by 6%–10% compared with the DPFS-OCS algorithm with the PF algorithm.

Keywords

long term evolution / interference avoidance / schedule algorithm / orthogonal complement space / fairness