  Massive multiple-input multiple-output (MIMO) communication systems have
drawn significant interest recently in next-generation wireless communications.
The use of a large number of antennas in massive MIMO makes the estimation of
channel state information very challenging. Accurate channel state information
is essential in capitalizing the advantages of the massive MIMO technology.
This paper proposes the application of the Ensemble Square Root Filter (EnSRF)
and a variant of EnSRF, namely a Particle wise Update version of the Ensemble
Square Root Filter (PUEnSRF) to estimate the time-selective frequency-flat
fading channel coefficients in the massive MIMO scenario. Simulation results
clearly indicate the remarkably superior accuracy and filter convergence of
PUEnSRF estimates as compared to the conventional particle filters.
