On the Spectral Efficiency of Multiuser Massive MIMO with Zero-Forcing Precoding

Abstract

This paper investigates the spectral efficiency (SE) of downlink massive MIMO systems, where we consider the Ricean fading channels and utilize the zero forcing precoder at the base state. An exact expression for the SE is derived and the tight lower and upper bounds are presented by utilizing the modified Jensen’s inequality. Our results show that as the number of transmit antennas grows to infinite or in the high signal-to-noise ratios regime, the lower and upper bound coincide, which are approximately equal to the exact expression for the spectral efficiency of system. In addition, we reduce the Ricean fading channels to the Rayleigh fading case, a tractable lower bound of SE is obtained, which is shown that our results cover a series of previous works as special cases. Finally, numerical results are presented to validate the theoretical analysis.