Memory polynomial based adaptive predistortion for Radio over Fiber systems

In this paper, a measurement apparatus based Radio-over-Fiber system prototype, including a Vector Signal Generator (VSG), a semiconductor laser, a photodetector and a spectrum analyzer, is build to study the nonlinear effects of the RoF system, which is widely regarded as a promising technique for microcell applications of the future wireless networks. The memory polynomial nonlinear model is utilized to compensate the nonlinearities in the RoF system. A three carrier Wideband Code Division Multiple Access(WCDMA) signal is applied to this test platform. The experimental results illustrate that the predistorter can improve the Adjacent Channel Power Ratio (ACPR) more than 10-dB.