Analysis of the cluster size in coordinated multipoint transmission

In this work we consider the optimization of the cell number to configure the different clusters in a coordinated multipoint transmission downlink environment where block diagonalization is employed to remove interference among users inside each cluster. Two possible schemes for the power allocation to each user´s transmission are compared, namely uniform power and waterfilling, We examine the weighted sum rate that may be achieved in an environment without interference or when base stations from other clusters transmit at maximum power. In both cases the number of cells per cluster that gives the best performance is quite high suggesting that, with this criterion, it is advisable to coordinate the maximum possible number of cells. The sum rates are obtained in a realistic multi-cell scenario using the SCM channel model with different antenna configurations.