  Designing a static state-feedback controller subject to structural constraint
achieving asymptotic stability is a relevant problem with many applications,
including network decentralized control, coordinated control, and sparse
feedback design. Leveraging on the Projection Lemma, this work presents a new
solution to a class of state-feedback control problems, in which the controller
is constrained to belong to a given linear space. We show through extensive
discussion and numerical examples that our approach leads to several advantages
with respect to existing methods: first, it is computationally efficient;
second, it is less conservative than previous methods, since it relaxes the
requirement of restricting the Lyapunov matrix to a block-diagonal form.
