Performance Degradation Due to OFDM-UWB Radio Signal Transmission Along Dispersive Single-Mode Fiber

The performance degradation of orthogonal frequency-division multiplexing (OFDM) ultra-wideband (UWB) radio signals caused by transmission along dispersive single-mode fiber is assessed theoretically and by numerical simulation. It is shown that the performance degradation of OFDM-UWB signals caused by fiber dispersion is due to the power fading induced on the subcarrier showing stronger fading. Results show that the power fading description based on a small signal analysis provides good estimates of the optical signal-to-noise ratio degradation for OFDM-UWB signals with modulation index (defined as the ratio between the root-mean-square voltage of the OFDM-UWB signal and the bias voltage of the Mach-Zehnder modulator) values up to 18%. This is a pessimistic value for some OFDM-UWB carrier frequencies.