  One of the most important properties of orbital angular momentum (OAM) of
photons is that the Hilbert space required to describe a general quantum state
is infinite dimensional. In principle, this could allow for encoding
arbitrarily large amounts of quantum information per photon, but in practice,
this potential is limited by decoherence and errors. To determine whether
photons with OAM are suitable for quantum communication, we numerically
simulated their passage through a turbulent atmosphere and the resulting
errors. We also proposed an encoding scheme to protect the photons from these
errors, and characterized its effectiveness by the channel fidelity.
