The impact of CSI errors and pilot contamination on the pilot-to-data power ratio

Abstract

Pilot symbols are used to estimate channel state information (CSI) in Massive Multiple-input Multiple-output (MIMO) systems, the pilot-to-data power ratio (PDPR) is known to have an impact on estimation result. However, the works before only consider the one cell model which has no pilot contamination. This paper focus on the impact of imperfect CSI and pilot contamination on pilot-to-data power ratio. It investigates the impact of PDPR to minimize mean square error (MSE) of uplink data transmission of Massive MIMO systems. First, the MSE expressions of uplink data transmission of Massive MIMO system is derived, then a method to estimate channel covariance matrix and reduce the impact of pilot contamination is introduced, finally we compare the result to show the impact of PDPR on minimize MSE. The result shows PDPR has a impact on the uplink received data MSE of Massive MIMO system.