Analysis of Precoding-Based Pilot Decontamination Methods in Massive MIMO Systems

During transmission of information, massive multi-input multiple-output (MIMO) antenna system encounters inter-cell interference, called pilot contamination that limits the capacity. Recent developments in massive MIMO technology have provided a plethora of methods to reduce pilot contamination using precoding in massive MIMO. However, a trade-off exists between the system performance based on achieved spectral efficiency in relation to the sumrates and bit error rates and complexity in terms of iterations count, the number of optimization variables and the relative time consumed to resolve the optimization problems. The current literature contains insufficient information to address this trade-off, a consequence that hinders the advancement of research in pilot contamination. This study covers the gap through a detailed review of various linear and nonlinear schemes centered on the two contending metrics, namely spectral efficiency and complexity. A systematic review approach is adopted to analyze different related studies and their associated methodologies, results and limitations. Moreover, we provide recommendations for future research.