Comprehensive Impairment and Performance Description of Directly Modulated/Detected OOFDM Systems

In this paper, we obtain an analytical formulation to describe the penalty of the main important sources of impairment into the final performance in directly modulated/detected OOFDM systems. These equations aim to give a comprehensive description of deliberate clipping process at the OFDM transmitter, laser direct modulation, the impact of the channel impulse response length and the nonlinearity introduced by the laser, and the interplay between laser chirp and chromatic dispersion. Jointly, the provided expressions allow us, firstly, to analyze and understand the performance obtained in an OOFDM system in short-medium optical haul links, and, second, to optimize important transceiver parameters such as the clipping level, length of the cyclic pre/postfix, and laser modulation index.