  This paper proposes a novel joint channel estimation and beamforming approach
for multicell wideband massive multiple input multiple output (MIMO) systems.
With the proposed channel estimation and beamforming approach, we determine the
number of cells $N_c$ that can utilize the same time and frequency resource
while mitigating the effect of pilot contamination. The proposed approach
exploits the multipath characteristics of wideband channels. Specifically, when
the channel has a maximum of $L$ multipath taps, \textcolor{red}{it is shown
that $N_c\leq L$ cells can estimate the channels of their user equipments (UEs)
and perform beamforming while mitigating the effect of pilot contamination.} In
a typical long term evolution (LTE) channel environment having delay spread
$T_d=4.69\mu$ second and channel bandwidth $B=2.5$MHz, we have found that
$L=18$ cells can use this band. In practice, $T_d$ is constant for a particular
environment and carrier frequency, and hence $L$ increases as the bandwidth
increases. All the analytical expressions have been validated, and the
superiority of the proposed design over the existing ones is demonstrated using
extensive numerical simulations both for correlated and uncorrelated channels.
The proposed channel estimation and beamforming design is linear and simple to
implement.
