Load-Aware Coordinated Multipoint Joint Transmission in Dense Heterogeneous Networks: Downlink Coverage and Throughput Limits

Abstract

In this paper, we propose a (cell) load-aware approach to performing the downlink coordinated multi-point joint transmission (JT-CoMP) scheme in a dense heterogeneous cellular network (HetNet) consisting M tiers of different kinds of base stations (BSs). Inspiring from the fact that there could exist a considerable number of the void BSs in a dense HetNet that are not associated by any users, this load-aware JT-CoMP scheme is able to coordinate the void BSs so as to enhance the downlink transmission of the non-void BSs. Using such a CoMP scheme, the fundamental upper and lower limits on the coverage and ergodic link throughput of a user with downlink MISO channel are accurately found in a low-complexity approximated form and they straightforwardly show that the load-aware JT-CoMP scheme has the capability of significantly increasing the coverage and ergodic link throughput of a user as long as the user intensity is not very much higher than the total intensity of the BSs. Numerical results validate the accuracy and correctness of the analytical results and demonstrate the huge gains of the coverage and the ergodic link throughput exploited by the proposed load-aware JT-CoMP scheme.