AlGaInP optical source integrated with fiber links and silicon avalanche photo detectors in fiber optic systems

This study has clarified aluminium gallium indium phosphide (AlGaInP) optical source integrated with fiber links and silicon avalanche photodetectors in fiber optic systems. The output spectral power, rise time, signal frequency and resonance frequency for AlGaInP laser diode. The laser diode rise time, output spectral power and resonance/signal frequencies versus injection current and ambient temperatures are sketched. The silica doped germanium fiber link pulse broadening and the signal fiber bandwidth are investigated against temperature variations. The signal per noise ratio is related to Q value and bit error rate (BER) at the receiving point (Si avalanche photodetector (APD)) are sketched with temperature.

Adaptive digital predistortion to linearize nonlinear distortion in radio-over-fiber links

The application of Radio-Over-Fiber (ROF) links are widely used in wireless communications. However, due to the nonlinear characteristics of the link distortion will be introduced as the output of the link. As a result, unwanted frequencies and signals end up being delivered by an antenna. In the thesis, a technique of adaptive digital predistortion is presented. This complex gain predistortion technique requires that no detailed knowledge of the link characteristics and supports tracking of the modifications and drifts in the link characteristic. A prototype of this predistortion system is designed and implemented on a Field Programmable Gate Array (FPGA). Experiment results show that amplitude and phase nonlinearity of the ROF link are compensated with the system. The experiments demonstrated that this system show promising results and that good compensation of distortion is achieved.

Adaptive digital predistortion to linearize nonlinear distortion in radio-over-fiber links

The application of Radio-Over-Fiber (ROF) links are widely used in wireless communications. However, due to the nonlinear characteristics of the link distortion will be introduced as the output of the link. As a result, unwanted frequencies and signals end up being delivered by an antenna. In the thesis, a technique of adaptive digital predistortion is presented. This complex gain predistortion technique requires that no detailed knowledge of the link characteristics and supports tracking of the modifications and drifts in the link characteristic. A prototype of this predistortion system is designed and implemented on a Field Programmable Gate Array (FPGA). Experiment results show that amplitude and phase nonlinearity of the ROF link are compensated with the system. The experiments demonstrated that this system show promising results and that good compensation of distortion is achieved.