Performance Analysis of Enhanced Dynamic Point Selection CoMP Scheme for Heterogeneous Networks

In this paper, we study the performance of Dynamic Point Selection (DPS) Cooperative Multipoint (CoMP) techniques in heterogeneous networks (Hetnets). We show that to obtain good performance with spectral efficiency (SE) based DPS, the transmission point (TP) switching metric should be based on weighted average of the Almost Blank Subframes (ABS) and non-ABS SE values, where the weights are the fraction of ABS and non-ABS subframes. We compare the performance of SE-based DPS with intra-site CoMP cluster and with 'liquid cooperation cluster.' Our results show that the system performance in the two cases are similar when the Cell Range Extension (CRE) is set to the optimal value. We also enhance the load-based DPS scheme, the preferred scheme with finite buffer traffic, and show that the TP switching metric requires a proper interference mitigation factor to discourage switches that make a large compromise in SE. This is especially important in Hetnets where there is usually a large load difference between the macro and small cells. Finally, we show how the DPS scheme can work in the presence of non-ideal backhaul between cooperating neighboring cells and quantify the performance gains obtained in such scenarios.