  Millimeter wave communication is eminently suitable for high-rate wireless
systems, which may be beneficially amalgamated with intelligent reflecting
surfaces (IRS), relying on beam-index modulation. Explicitly, we propose three
different architectures based on IRSs for beam-index modulation in millimeter
wave communication, which circumvent the line-of-sight blockage of millimeter
wave frequencies. We conceive both the optimal maximum likelihood detector and
a low-complexity compressed sensing detector for the proposed schemes. Finally,
the schemes conceived are evaluated through extensive simulations, which are
compared to our analytically obtained bounds.
