Direct-Detection Optical OFDM Transmission System With Pre-Emphasis Technique

Abstract

We investigated the effect of subcarriers-to-subcarriers mixing interference and frequency fading in direct-detection (DD) optical orthogonal frequency-division multiplexing (OFDM) system. We also proposed and experimentally demonstrated a novel DD OFDM transmission scheme with pre-emphasis technique. By pre-emphasizing the power of the OFDM subcarriers at the high frequency, the received sensitivity at our experiment was improved about 2 dB at a bit error rate of 1 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> after 100-km SMF-28 transmission compared to the regular one without this technique.