Date Added: Oct 2010
In this paper, the authors present optimal and near-optimal frame synchronization algorithms for a packet-based free-space optical communications system. Optimal preamble detection in the presence of random data was first studied by Massey for radio frequency phase-shift keying modulation over an additive white Gaussian noise channel with statistically independent noise. That analysis demonstrated, perhaps somewhat counterintuitively, that correlation against the known preamble is suboptimal and that the degradation from optimal performance can be severe. Subsequent researchers following Massey's approach have developed algorithms that apply to optical communication systems with pulse-position modulation over a Poisson channel, with similar results.