Hybrid fiber coaxial network optical transport system with distortion control

Abstract

Linearized optical transmitter units are described for a hybrid optical fiber coaxial cable network. The linearized optical transmitter unit can comprise a directly-modulated or externally-modulated laser optically coupled to an optical conduit directed to an optical fiber communications link and electrically coupled to an electrical RF source line that provides an RF source to drive the laser or an external modulator for a light beam from the laser. A linearization information electrical component comprising memory and/or a processor, and a data output configured to transmit linearization enabling data for input into a direct digital synthesis engine that enables the direct digital synthesis engine to generate an RF signal wherein nonlinear responses of the transmitter and/or the optical fiber communications link are pre-compensated, in which the data is specific for the optical transmitter and/or the optical fiber communications link. An electronic communication channel can connected to the data output of the electrical component to communicate the linearization enabling data external to the linearized optical transmitter unit suitable for communication to the direct digital synthesis engine. The linearized optical transmitter can be assembled in a plug-in module. Corresponding HFC systems and methods are also described.