MORE REFERENCES:
W. Sauer-Greff, A. Dittrich, M. Lorang, and M. Siegrist (2001-04-16). “Maximum-Likelihood Sequence Estimation of Nonlinear Channels in High-Speed Optical Fiber Systems” (PDF). The Telecommunications Research Center Vienna.
Andrea Goldsmith (2005). “Maximum Likelihood Sequence Estimation”. Wireless Communications. Cambridge University Press. pp. 362–364. ISBN 9780521837163.
Crivelli, D. E.; Carrer, H. S., Hueda, M. R. (2005) “Performance evaluation of maximum likelihood sequence estimation receivers in lightwave systems with optical amplifiers”, Latin American Applied Research, 35 (2), 95–98.
Katz, G., Sadot, D., Mahlab, U., and Levy, A.(2008) “Channel estimators for maximum-likelihood sequence estimation in direct-detection optical communications”, Optical Engineering 47 (4), 045003. doi:10.1117/1.2904827