  We carry out a theoretical analysis of the uplink (UL) of a massive MIMO
system with per-user channel correlation and Rician fading, using two
processing approaches. Firstly, we examine the linear minimum-mean-square-error
receiver under training-based imperfect channel estimates. Secondly, we propose
a statistical combining technique that is more suitable in environments with
strong Line-of-Sight (LoS) components. We derive closed-form asymptotic
approximations of the UL spectral efficiency (SE) attained by each combining
scheme in single and multi-cell settings, as a function of the system
parameters. These expressions are insightful in how different factors such as
LoS propagation conditions and pilot contamination impact the overall system
performance. Furthermore, they are exploited to determine the optimal number of
training symbols which is shown to be of significant interest at low Rician
factors. The study and numerical results substantiate that stronger LoS signals
lead to better performances, and under such conditions, the statistical
combining entails higher SE gains than the conventional receiver.
