An analytical theory for the evaluation of the performance of a nonreturn-to-zero (NRZ) transmission system operating in weakly normally dispersive nonlinear fibers is presented. Explicit expressions are given to compute an extimate of the transmission bit error rate, and those are compared with results obtained through numerical simulations. A good agreement is found, both for systems having fibers with a constant dispersion value, and for systems encompassing dispersion management technique.
