POSTDISTORTION CIRCUIT FOR REDUCING DISTORTION IN AN OPTICAL COMMUNICATIONS SYSTEM

摘要

A postdistortion network (36) for a receiver at a receiver location (12) in an optical transmission system is disclosed. The receiver converts an optical signal carried over an optical transmission link (11) to an RF signal. The postdistortion network (36) includes an optical terminal for receiving the RF signal and a distortion generator for generating a distortion signal from the RF signal. An adjusting circuit adjusts the phase and amplitude of the distortion signal based on distortion at said receiver location (12). The adjusted distortion signal is combined with the RF signal in order to cancel or substantially suppress distortion in the RF input signal. The present invention permits individual receivers in an optical transmission system to be compensated for distortion which may be unique to that receiver location. A communication system including a predistortion network and a postdistortion network is also disclosed.