  Due to turbulence and tracking errors, free-space optical channels involving
mobile transceivers are characterized by a signal's partial loss or complete
erasure. This work presents an error correction protocol capable of protecting
a signal passing through such channels by encoding it with an ancillary
entangled bipartite state. Beyond its ability to offer protection under
realistic channel conditions, novel to our protocol is its ability to encompass
both classical and quantum information on the encoded signal. We show how,
relative to non-encoded direct transmission, the protocol can improve the
fidelity of transmitted coherent states over a wide range of losses and erasure
probabilities. In addition, the use of ancillary non-Gaussian entangled
bipartite states in the signal encoding is considered, showing how this can
increase performance. Finally, we briefly discuss the application of our
protocol to the transmission of more complex input states, such as multi-mode
entangled states.
