  Characterizing self-interference is essential to the design and evaluation of
in-band full-duplex communication systems. Until now, little has been
understood about this coupling in full-duplex systems operating at millimeter
wave (mmWave) frequencies, and it has been shown that the highly-idealized
models proposed for such do not align with practice. This work presents the
first spatial and statistical model of mmWave self-interference backed by
measurements, enabling engineers to draw realizations that exhibit the
large-scale and small-scale spatial characteristics observed in our nearly 6.5
million measurements taken at 28 GHz. Core to our model is its use of system
and model parameters having real-world meaning, which facilitates its extension
to systems beyond our own phased array platform through proper
parameterization. We demonstrate this by collecting nearly 13 million
additional measurements to show that our model can generalize to two other
system configurations. We assess our model by comparing it against actual
measurements to confirm its ability to align spatially and in distribution with
real-world self-interference. In addition, using both measurements and our
model of self-interference, we evaluate an existing beamforming-based
full-duplex mmWave solution to illustrate that our model can be reliably used
to design new solutions and validate the performance improvements they may
offer.
