Spectral Efficiency Analysis of D2D-Enabled Massive MIMO Systems

This paper considers a device-to-device (D2D) communication-enabled multi-cell massive multi-input multi-output (MIMO) system, where multiple D2D pairs reuse the pilot signal allocated to the cellular users. The closed-form expressions for the spectral efficiency and its lower-bounds are derived using maximal ratio combining. To closely model the channel in the practical environment, a combination of line-of-sight (LoS) path and a stochastic non-line-of-sight (NLoS) component describing a spatially correlated multipath environment is considered. To characterize the achieved spectral efficiency for considered channel modeling, simulations are performed. The obtained results show that the system performance achieved with the Rician correlated fading is higher than the spectral efficiency achieved with Rayleigh-fading.