Equalização para sistemas OFDM óptico

Abstract

In the last decade the OFDM (Orthogonal Frequency Division Multiplex ) technique had a great growth in wireless and wireline communications. The optical communication area had a great development too in the last years. The union of this two areas has recently started: the OFDM technique and the optical channel. Inside this background this thesis had as main objective study this union and propose a simple optical system wich the dispertion compensation and frequency band allocation lays under OFDM responsability through the pilote tones technique. This technique is named OOFDM (Optical OFDM ). In this thesis we present an optical system composed of standard monomode fiber with intensity modulation and direct detection (IM-DD). We have used a base band OFDM transmission system with hermitian symmetry, 16-QAM mapping and bit loading for band allocation. In order to minimize the chromatic dispersion effects over the optical channel we have developed channel estimation and equalization based on pilot tones and linear interpolation. Our simulations have shown that the transmission in 20 km fiber with 47 Gbps rate, BER ≈ 10−5 and EV M ≈ −22 dB. This overcomes assured this technique actuation in metropolitans networks and as last-mile solution for high rates.