Receivers for binary optical communications-optimisation under the Chernoff bound in the presence of intersymbol interference

A method for optical fiber receiver optimization based on a Chernoff bound and including intersymbol interference is presented. The description of relevant models is given, followed by a detailed mathematical characterization of both the detected optical power and colored Gaussian noise generated within the receiver. These mathematical tools are used to develop an expression for the Chernoff bound on the average error probability. The Chernoff bound is minimized using differential and variational methods; as a result a differential equation is obtained whose solution is the optimum filter. For the purpose of illustration this equation is applied to the specific case of Poisson signalling and a closed form solution is obtained. In the absence of intersymbol interference the result reduces to that obtained using a maximum likelihood criterion, so providing a partial check on the validity of the method.