Análise de sistemas de comunicação óptica com multiplexagem de subportadora e transmissão em banda lateral única

Tese dout., Engenharia Electrónica e Computação, Universidade do Algarve, 2005The transmission of optical single sideband signal with subcarrier multiplexing is a very promising technique for future telecommunications systems. This is an optical technology which combines optical single sideband (OSSB) modulation advantages with the subcarrier multiplexing (SCM) characteristics of simplicity and flexibility. This thesis analyses OSSB/SCM systems performance with direct detection and electrical coherent demodulation and compares its performance when different modulation schemes are applied to the individual data channels. This analysis is extended to systems using optical the in-line amplifiers. Analytical methods are developed to evaluate the degradation of performance of these system caused by laser intensity noise at fiber output, intermodulation distortion, optical amplifier noise and nonlinear four-wave mixing effect from optical fibers. Special attention is given to the power suppression ratio of the optical carrier since it is found to be an important parameter on the system performance. The obtained results show that the system performance has a great sensitivity to the system parameters. This system behaviour requires a careful choice of system parameters in order to achieve optimum system performance.Fundação para a Ciência e Tecnologia (FCT