Channel estimators for maximum-likelihood sequence estimation in direct-detection optical communications

We analyze adaptive maximum-likelihood sequence estimation in the presence of chromatic dispersion for optical communication with on-off keying and a direct-detection receiver. The study focuses on two probability density function estimation techniques: parametric and nonparametric. We present a comparison analysis of the performance difference between the two techniques and validate that with experimental results. (C) 2008 Society of Photo-Optical Instrumentation Engineers.