Joint cell association, component carrier selection and beamforming on carrier aggregated channels in heterogeneous networks

This paper considers the joint cell association, component carrier selection and beamforming on carrier aggregated channels in Heterogeneous Networks. The problem is modelled as a sum rate maximization problem with constraints and is solved by a successive allocation update algorithm. The proposed algorithm starts with a cell association stage in which the serving cell will be decided with an objective of maximizing the network sum rate while simultaneously minimizing the sum of interference power towards the other cells, then in the next stage, the beamforming and carrier selection will be iteratively carried out. The beamforming is achieved by a signal-to-weighted-leakage plus-noise ratio, afterwards, carrier selection is used to shut down a subset of the component carrier in order to allow for a perfect interference removal at the receive side in the large dense low power node deployment scenario. Simulation results show that the proposed algorithm not only exploits additional degrees of freedom provided by multiple antennas and component carriers, but also ensures that the inter- and intra-cell interference will not overwhelm the cell-splitting gains.