Modeling and linearization of nonlinear radio-over-fiber system

Abstract

© 2008 Society of Photo-Optical Instrumentation Engineers. The biggest concern in the use of radio-over-fiber (ROF) links in wireless access is the limited dynamic range due to nonlinear distortion (NLD). We introduce the configuration of the ROF system, then the Volterra series, a higher-order adaptive-filter-based nonlinearity compensation scheme, is proposed to model the system and compensate the NLD. The adaptive algorithms of least mean square (LMS) and recursive least squares (RLS) for identifying Volterra kernels are both studied. The simulated results based on the measured results show that both Volterra LMS and Volterra RLS can be used to model the system, and gradually saturating amplitude nonlinearity can be adequately linearized by the latter.