Interference Cancellation Using Relay Station in Heterogeneous Networks

This paper proposes interference cancellation that utilizes relay stations (RSs). In Long Term Evolution (LTE) Advanced, heterogeneous networks in which femto and picocells are overlaid onto macrocells are extensively discussed. However, interference between macro and pico(femto)cells arises due to their different transmit power levels. Unlike conventional cooperative transmission schemes, the RS decodes interference in the first transmit timing period and forwards it to the user equipment (UE) in the second period. Moreover, cooperative transmission can be achieved without stopping the transmission from the base station (BS) to UE when forwarding the interference from the RS to the UE by utilizing the fact that signal to noise power ratio (SNR) between the RS and UE is much greater than that between the BS and UE. The effectiveness of the proposed method and the optimal relay arrangement are shown based on computer simulation when considering heterogeneous pathloss models.