  Decoherence is the fundamental obstacle limiting the performance of quantum
information processing devices. The problem of transmitting a quantum state
(known or unknown) from one place to another is of great interest in this
context. In this work, by following the recent theoretical proposal [Opt. Eng.
{\bf 59}, 061625 (2020)] we study an application of quantum state-dependent
pre- and post-processing unitary operations for protecting the given
(multi-qubit) quantum state against the effect of decoherence acting on all
qubits. We observe the increase in the fidelity of the output quantum state
both in a quantum emulation experiment, where all protecting unitaries are
perfect, and in a real experiment with a cloud-accessible quantum processor,
where protecting unitaries themselves are affected by the noise. We expect the
considered approach can be useful for analyzing capabilities of quantum
information processing devices in transmitting known quantum states. We also
demonstrate an applicability of the developed approach for suppressing
decoherence in the process of distributing a two-qubit state over remote
physical qubits of a quantum processor.
