Optical heterodyne binary-DPSK systems: a review of analysis and performance

We review the work on optical heterodyne binary-DPSK systems. In particular we show why the study of these systems has been so challenging and discuss the techniques which have been developed to analyse the standard DPSK receiver. Next we describe the methods used to develop and analyse improved receiver structures and comment on the impact of improved performance and lowered error rate floors. We discuss the work on suboptimal receivers and outline the current state of the search for a truly optimal receiver. This work include a considerable discussion of the modeling and analysis of laser phase noise since it is this noise which makes the study of coherent optical systems so complex. We describe the historical development of this work from early approximate techniques to the accurate approaches currently emerging in the literature. We also evaluate the contributions made and outline their strengths, weaknesses and areas of use