Predistortion technique for mitigating the Mach-Zehnder modulator nonlinearity effect in DD-OFDM-UWB optical transmission systems

摘要

Predistortion of orthogonal frequency-division multiplexing (OFDM) ultra wideband (UWB) signals is proposed to mitigate the nonlinearity of Mach-Zehnder modulator used as electro-optical converter in direct-detection OFDM-UWB optical communication systems. Theoretical derivation of the predistorter characteristic is performed. Performance results in terms of error vector magnitude (EVM) obtained by numerical simulation of such OFDM-UWB system are presented and discussed. It is shown that 2.5 dB of improvement in the OFDM-UWB system performance can be obtained by using the presented predistortion technique.