Optimization study of advanced modulation formats for 10-Gb/s metropolitan networks

A detailed study of alternative modulation formats appropriate for 10-Gb/s wavelength-division-multiplexing metropolitan area networks is performed to evaluate their tolerance to linear impairments such as optical-signal-to-noise-ratio degradation, dispersion, filter concatenation, interband/intraband crosstalk, as well as their interplay. Point-to-point links and optical add-drop multiplexer chain and ring architectures are investigated, and optimum design parameters are obtained. Through extensive sets of simulation results, it is shown that some of these formats are very tolerant to linear impairments when compared with conventional nonreturn to zero.