  Characterizing the minimal communication needed for the quantum channel
simulation is a fundamental task in the quantum information theory. In this
paper, we show that, in fidelity, the quantum channel simulation can be
directly achieved via quantum state splitting without using a technique known
as the de~Finetti reduction, and thus provide a pair of tighter one-shot
bounds. Using the bounds, we also recover the quantum reverse Shannon theorem
in a much simpler way.
