Zafiriou, E.Morari, M.The problem of the direct design of the closed-loop transfer function matri'; is addressed for multivariable discrete systems. The limitations imposed by unstable zeros, time delays and the structure associated with these are quantified. A design procedure is formulated that provides the designer with quantitative measures for evaluating the tradeoffs between different closed-loop interaction structures and durations. The problem of intersample rippling is also considered. The procedure requires only linearalgebra operations, includes the eventual construction of the feedback controller in state space, and is presented in a way that allows its straightforward computer implementation.en-USDigital Controller Design for Multivariable Systems with Structural Closed-Loop Performance Specifications.Technical Report