Effective Channel Blind Estimation in Cell-Free Massive MIMO Networks

This letter investigates the performance of a new blind method for effective channel estimation in user-centric cell-free massive multiple-input multiple-output (MIMO) networks. To this end, comparisons with the perfect and statistical channel state information (CSI) methods are performed assuming different precoding choices. The results demonstrate that blind estimation can significantly reduce normalized mean-square error and improve spectral efficiency compared with the statistical CSI method. Additionally, blind estimation works even when the asymptotic arguments that inspire the algorithm do not hold, performs reasonably well in the presence of pilot contamination, and can boost the performance of systems using maximum-ratio (MR) precoding.