This paper uses convex analysis for the pole assignment design of discrete-time SISO systems incorporating robust stability against norm bounded parametric perturbations in the plant transfer function. The method involves designing an overparameterized pole assignment controller for the nominal plant with the overparameterization chosen to reduce the size of changes in the closed-loop characteristic equation which result from plant perturbations. Sufficiency bounds on the l(p) norm of the perturbation guaranteeing stability are obtained.