We consider a downlink multiuser multiple-input multiple output (MIMO) system employing regularized zero-forcing (RZF) precoding. We derive the asymptotic signal-to-leakage-plus-noise ratio (SLNR) as both the number of antennas and the number of users go to infinity at a fixed ratio. Focusing on the symmetric uncorrelated channels, we show that the SLNR is asymptotically equal to signal-to-interference-plus-noise ratio (SINR) which allows us to optimize the user loading for spectral efficiency. The results show that the optimal user loading varies depending on the channel signal-to-noise ratio (SNR) but is equal to one in both the low or high SNR regimes.
@article{arxiv.1609.03184,
title = {Optimal User Loading in Massive MIMO Systems with Regularized Zero Forcing Precoding},
author = {Sungwoo Park and Jeonghun Park and Ali Yazdan Panah and Robert W. Heath},
journal= {arXiv preprint arXiv:1609.03184},
year = {2016}
}