I. Introduction
To meet the ever increasing data rate requirements of mobile users, 3GPP Long Term Evolution (LTE) [1] targets a spectrum reuse factor of 1 to achieve higher system capacity and spectrum efficiency. The reuse factor of means that there are cells that cannot use the same spectrum for transmission. However, frequency reuse factor of 1 inevitably causes considerable inter-cell interference (ICI) by the users using the same frequency in adjacent cells in these orthogonal frequency division multiplexing (OFDM) [2]–[4] systems. In particular the users at the cell edge experience high ICI. Therefore, effective inter-cell interference coordination (ICIC) and spectrum usage management is an important and challenging issue for the design of wireless communication systems.