  A massive MIMO system entails a large number of base station antennas M
serving a much smaller number of users. This leads to large gains in spectral
and energy efficiency compared with other technologies. As the number of
antennas M grows, the performance of such systems gets limited by pilot
contamination interference. Large Scale Fading Precoding/Postcoding (LSFP) was
proposed in literature for mitigation of pilot contamination. It was shown
recently that in channels without spatial correlation (uncorrelated base
station antennas) LSFP leads to large spectral-efficiency gains. Also,
recently, it was observed that if a channel has spatial correlation, then one
can use this correlation to drastically reduce the pilot contamination
interference in the asymptotic regime as M tends to infinity. In this work, we
analyze the performance of Uplink (UL) transmission of massive MIMO systems
with finitely many antennas M for channels with spatial correlation. We extend
the idea of LSFP to correlated channel models and derive SINR expressions that
depend only on slow fading channel components for such systems with and without
LSFP. These simple expressions lead us to simple algorithms for transmit power
optimization. As a result, we obtain a multi-fold increase in data transmission
rates.
