  This short tutorial presents several ideas for designing dual function radar
communication (DFRC) systems aided by intelligent reflecting surfaces (IRS).
These problems are highly nonlinear in the IRS parameter matrix, and further,
the IRS parameters are subject to non-convex unit modulus constraints. We
present classical semidefinite relaxation based methods, low-complexity
minorization based optimization methods, low-complexity Riemannian manifold
optimization methods, and near optimal branch and bound based methods.
