Patent ID: 11901951
Assignee: FUJITSU LIMITED
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 16:
17. A digital predistortion apparatus, comprising:
a non-linear predistorter in an optical transmitter, configured to perform real-time predistortion processing on a signal input to the non-linear predistorter according to a predistortion coefficient;
a decider in an optical receiver, configured to decide an input signal before decision to generate a signal after decision; and
a distorter coefficient updating apparatus at an optical receiver side, the distorter coefficient updating apparatus comprising a processor configured to:
perform non-linear re-distortion processing on the signal after decision according to a first distorter coefficient to generate a first reference signal; and
calculate a second distorter coefficient according to the first reference signal and the signal before decision, or according to the first reference signal, the signal after decision, and the signal before decision, and
wherein the second distorter coefficient is fed back to the processor as the first distorter coefficient of the processor in a next update, and the second distorter coefficient is fed back to the non-linear predistorter as a predistortion coefficient for the non-linear predistorter to perform a non-linear predistortion processing on the signal input to the non-linear predistorter,
wherein the first distorter coefficient adopted by the processor is a same coefficient as the predistortion coefficient adopted by the non-linear predistorter.