Linearization Technologies for Broadband Radio-Over-Fiber Transmission Systems

Abstract

Linearization technologies that can be used for linearizing RoF transmission are reviewed. Three main linearization methods, i.e. electrical analog linearization, optical linearization, and electrical digital linearization are presented and compared. Analog linearization can be achieved using analog predistortion circuits, and can be used for suppression of odd order nonlinear distortion components, such as third and fifth order. Optical linearization includes mixed-polarization, dual-wavelength, optical channelization and the others, implemented in optical domain, to suppress both even and odd order nonlinear distortion components, such as second and third order. Digital predistortion has been a widely used linearization method for RF power amplifiers. However, digital linearization that requires analog to digital converter is severely limited to hundreds of MHz bandwidth. Instead, analog and optical linearization provide broadband linearization with up to tens of GHz. Therefore, for broadband radio over fiber transmission that can be used for future broadband cloud radio access networks, analog and optical linearization are more

Robustness analysis of a parallel two-box digital polynomial predistorter for an SOA-based CO-OFDM system

“…A broad variety of methods have been studied in literature for linearizing optical links or radio-over-f ber (RoF) links over the past few years, with a few approaches being specif cally designed to cope with the nonlinear effects of SOA [12] [13]. The various methods can be classif ed into three main groups: optical linearization, electrical analog linearization and electrical digital linearization [14]. A digital baseband predistortion (DPD) is considered throughout this study, which consists in pre-compensating the transmitter nonlinear characteristics based on a black-box behavioral model.…”

Simple pre-distortion schemes for improving the power efficiency of SOA-based IR-UWB over fiber systems

“…A broad variety of linearization techniques are discussed in the literature [16]- [18], [21] for reducing the nonlinear effects associated to optical communication systems. The different approaches can be classified into two main groups, electrical linearization and optical linearization.…”

Enhancing distributed feedback‐standard single mode fiber‐radio over fiber links performance by neural network digital predistortion

“…Efficiently reducing these nonlinearities through linearization techniques has critical importance. In previous years, different linearization methods have been proposed, 3,5,6,[14][15][16][17][18][19][20] however, DPD demonstrated itself as a successful technique in mollifying the impairments in RoF systems. [16][17][18] Traditional volterra based methods such as memory polynomial (MP) and generalized MP (GMP) were used successfully in References 16-20 reducing the laser nonlinearities.…”