  Quantum channel, as the information transmitter, is an indispensable tool in
quantum information theory. In this paper, we study a class of special quantum
channels named the mixed-permutation channels. The properties of these channels
are characterized. The mixedpermutation channels can be applied to give a lower
bound of quantum coherence with respect to any coherence measure. In
particular, the analytical lower bounds for l1-norm coherence and the relative
entropy of coherence are shown respectively. The extension to bipartite systems
is presented for the actions of the mixed-permutation channels.
