Effect of spatial correlation on the ergodic capacity for downlink massive MU-MIMO systems

Massive Multiple-Input Multiple-Output (MIMO) is an emerging technology for the future 5G wireless communication systems and has been expected to dramatically improve the performance over the years. The main aim of this paper is to investigate the ergodic capacity of the downlink massive Multi-User (MU-MIMO) system under spatially correlated Rayleigh fading channels using two correlative models, namely the Kronecker and the Weichselberger models. To the best of our literary search, the impact of spatial correlation on the downlink ergodic capacity using the Kronecker and Weichselberger channel models was not previously investigated, more particularly with large scale antennas. Our results are valid for scenarios with a number of transmitting antennas which is greater than the number of users, in the presence of arbitrary correlation among them. It is demonstrated that the capacity loss is almost negligible even with a correlation coefficient between the transmitting antenna elements as large as 0.6.