  The goal of this paper is to calculate bound, resonant and scattering states
in the coupled-channel formalism without relying on the boundary conditions at
large distances. The coupled-channel solution is expanded in eigenchannel bases
i.e. in eigenfunctions of diagonal Hamiltonians. Each eigenchannel basis may
include discrete and discretized continuum (real or complex energy) single
particle states. The coupled-channel solutions are computed through
diagonalization in these bases. The method is applied to a few two-channels
problems. The exact bound spectrum of the Poeschl-Teller potential is well
described by using a basis of real energy continuum states. For deuteron
described by Reid potential, the experimental energy and the S and D contents
of the wave function are reproduced in the asymptotic limit of the cutoff
energy. For the Noro-Taylor potential resonant state energy is well reproduced
by using the complex energy Berggren basis. It is found that the expansion of
the coupled-channel wave function in these eigenchannel bases require less
computational efforts than the use of any other basis. The solutions are stable
and converge as the cutoff energy increases.
