The Potential of Restricted PHY Cooperation for the Downlink of LTE-Advanced

We investigate the potential of restricted PHY co- operation for the downlink of 4G networks. The cooperation is restricted to a cluster of eNodeBs. We distinguish between low and high mobility users, and propose two appropriate cooperation methods. The goal is to guarantee high user rates even on cell edges. We present a simulation study to analyze the spectral efficiency achieved by cooperation methods for urban micro cells. To investigate their influence on coordinated multipoint (CoMP), we consider different frequency allocation strategies and different sector orientations in a cell. In addition, we compare CoMP transmission to Multiuser MIMO and investigate how cooperation can improve power allocation. Based on the results, we provide important insights into future cell planing aspects.