Better Performance of Optical Transmitter Using Feedforward Linearisation System for Multi Service Operation in Radio over Fiber Links

摘要

Due to increasing the demand for multiservice operation and hence broadband access, the reliable and cost effective communication systems that can support anytime, anywhere, any media are needed. Radio over fiber technology is able to alleviate the increasing demand for high-bandwidth services but suffer from performance degradation due to the issue of noise and interference. A feedforward linearisation system is a powerfull technique that prefers because can reduce the broadband distortion in microwave/millimeter wave frequencies, reduce the all orders of distortion and the laser relative intensity noise (RIN) simultaneously. This paper investigated the proposed design of feedforward linearisasion system of directly modulated laser diode for radio over fiber application at frequency range 5 - 5.8 GHz. The simulation result of the system shown that the simultaneous reduction of IMD3 achieved up to 30 dB and RIN reduction up to 20 dB at frequency with 800 MHz bandwidth linearization. Likewise, the spurious free dynamic range of system was enhanced. In conclusion, the proposed system was suitable for multiservice radio over fiber system with operating frequency range 5 - 5.8 GHz.