Massive MIMO Systems in Time-Selective Channels

We investigate the performance of massive MIMO systems in time-selective channels using the first order Gauss-Markov Rayleigh fading channel model. We derive a closed form achievable rate for time-selective channels and provide a proof that the intracell interference effect in time-selective channels with constant amplitude pilots does not diminish in the asymptotic case. We show that there is a significant difference between the sum rate obtained using block-fading and time-selective models. We also show that the optimum training for block-fading may not be optimal for a time-selective channel, particularly for large numbers of antennas at the base station.