Note Technique: CSI estimation in massive MIMO systems and pilot contamination for different kinds of receiver architectures

In this paper we address the problem of channel state information guessing algorithms in the context of massive MIMO systems. We illustrate the problem of pilot contamination in the case where several cells share the same spectrum bandwidth and we calculate the capacity of the system for different receiver architectures: Maximum Ratio Combining, Zero-Forcing, MMSE. The theoretical expressions we obtained are the most accurate ones in the open literature of the field.