Codebook based Inter-Cell Interference Coordination for LTE

Current cellular systems suffer from co-channel interference, when simultaneous transmissions in other cells use the same physical resources. Schemes involving cooperation between Base Stations (BS) are currently discussed for further releases of the 3GPP Long Term Evolution (LTE) system as a promising method to mitigate co-channel interference for users located at cell-edge. The BS cooperation approach proposed in this paper applies to the Downlink (DL) of cellular systems and can be considered as an expansion of Inter-Cell Interference Coordination (ICIC) techniques to the spatial domain. Cooperating cells coordinate their antenna weights to reduce interference caused to selected users. This scheme uses an extension of the implicit DL channel feedback mechanism defined in current Frequency Division Duplex (FDD) cellular systems that is based on predefined codebooks of antenna weights. Performance evaluations by means of simulation show the capability of codebook based ICIC applied to LTE in terms of mean and cell-edge user throughput.