Analysis over Spectral Efficiency for Distributed Massive MIMO Systems with Temporally Correlated Channel

To analyze the impact of the time-variant channel for multiuser distributed massive multiple-input multiple-output (MIMO) system, the first order Gauss-Markov process was introduced to model the time-variant channel, where temporal correlation coefficient was adopted to characterize the degree of time-varying. Using the deterministic equivalent principles and the properties of random variable with Gamma distribution, we derived the closed-form expression of the uplink and downlink spectral efficiency including the temporal correlation coefficient in it, when the maximum ratio combining (MRC) detection and the maximum ratio transmission (MRT) precoding were employed. Meanwhile, the limiting performance of spectral efficiency was given when the ratio of the total number of antennas to the number of users goes to infinity, which indicates that the spectral efficiency decreases with temporal correlation coefficient without affecting the transmit power gain. Numerical simulations validate the accuracy of the proposed analytical expression of the spectral efficiency and shows that distributed massive MIMO outperforms centralized massive MIMO even with channel temporal correlation.