DFE Versus MLSE Electronic Equalization for Gigabit/s SI-POF Transmission Systems

In this letter, we compare three different types of electronic equalization techniques to compensate the limited bandwidth of gigabit/s step-index polymer optical fiber (SI-POF) transmission systems. In particular, we experimentally analyze the performance of a feed-forward equalizer (FFE), a feed-forward plus decision feedback equalizer (FFE+DFE), and a maximum likelihood sequence estimator (MLSE) equalizer in an optical link composed of a resonant cavity light-emitting diode (RC-LED), 50 m of SI-POF, and a photodiode. The investigation is carried out on a real hardware experiment based on available POF optoelectronics, while the equalization is implemented in software using an off-line processing approach. We show that the FFE+DFE solution pays only a limited penalty versus the much more complex MLSE algorithm. Our result shows that the FFE+DFE solution is a very good compromise between performance and complexity for a gigabit/s SI-POF system.