Teleportation of an unknown quantum state is an interesting issue in quantu
m information processing. Unit fidelity is achieved if sender and receiver
share a maximally entangled state corresponding to the Hilbert space of the
quantum state to be teleported. Realistic experiments necessarily make use
of passive optical devices such as beam splitters and optical fibers which
show losses. Losses however, are known to degrade the entanglement content
, and hence the teleportation fidelity, of any given quantum state. This is
due to the interaction with a noisy environment, say, an optical fiber. We
combine two methods, multiparticle entanglement and appropriate filtering,
to 'restore' some of the entanglement lost during the transmission process
. The filtering parameter and the basis used in the projective measurement
of the multiparticle-entangled state can be optimized for given material pr
operties (refractive index, fiber length).