Abstract
In this paper, Multi-User Multiple Input Multiple Output (MU-MIMO) cellular system is considered with large number of antennas at Base Station (BS). Maximal Ratio Combining (MRC) receiver is used at BS as it is efficient at low values of Signal-to-Noise Ratio (SNR). It is assumed that received signals at BS experience propagation environment effects including path loss, co-channel interference, fading and shadowing. Gamma-Gamma distribution is used to represent channel fading effects and Signal-to-Interference plus Noise Ratio (SINR) is modelled based on intercell and intracell interferences. Closed-form expressions for uplink Spectral Efficiency (SE) and Energy Efficiency (EE) are derived using Moment-Generating Function (MGF) approach. These efficiency metrics are illustrated as a function of MU-MIMO system and propagation environment parameters. Results show that efficiency metrics can be significantly improved at low values of users' transmitted power by increasing number of antennas at BS. The SE and EE of the system are enhanced by 0.02 bits/s/Hz/antenna and 4.22×104 bits/J/antenna, respectively, in such a system. Also, it is noted that increasing number of users in the system reduces efficiency metrics due to increased co-channel interference.