  In this paper, an analytical framework is provided to analyze the uplink
performance of device-to-device (D2D)-enabled millimeter wave (mmWave) cellular
networks with clustered D2D user equipments (UEs). Locations of cellular UEs
are modeled as a Poison Point Process (PPP), while locations of potential D2D
UEs are modeled as a Poisson Cluster Process (PCP).
Signal-to-interference-plus-noise ratio (SINR) outage probabilities are derived
for both cellular and D2D links using tools from stochastic geometry. The
distinguishing features of mmWave communications such as directional
beamforming and having different path loss laws for line-of-sight (LOS) and
non-line-of-sight (NLOS) links are incorporated into the outage analysis by
employing a flexible mode selection scheme. Also, the effect of beamforming
alignment errors on the outage probability is investigated to get insight on
the performance in practical scenarios. Moreover, area spectral efficiency
(ASE) of the entire network is determined for both underlay and overlay types
of sharing. Optimal spectrum partition factor is determined for overlay sharing
by considering the optimal weighted proportional fair spectrum partition.
