 
Summary: 1032 IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 45, NO. 9, SEPTEMBER 1997
Some Statistical Remarks on the Derivation of BER in
Amplified Optical Communication Systems
Felix Abramovich and Polina Bayvel
Abstract We consider the signal detection problem in am
plified optical transmission systems as a statistical hypothesis
testing procedure, and we show that the detected signal has a
wellknown chisquared distribution. In particular, this approach
considerably simplifies the derivation of biterror rate (BER).
Finally, we discuss the accuracy of the Gaussian approximations
to the exact distributions of the signal.
I. INTRODUCTION
IN THIS LETTER we consider the analysis and derivation
of the biterror rate (BER) in an optical transmission
system with alloptical amplifiers, such that the amplifiers
add Gaussian amplified spontaneous emission noise, dominant
over other possible noise sources. This is a wellknown
problem, studied by a number of authors (see, for example,
Marcuse [4]). In this contribution, we consider this problem
as a standard statistical hypothesis testing procedure that, in
