Distorter coefficient updating apparatus, method and digital predistortion apparatus

A distorter coefficient updating method applied at an optical receiver side where an optical receiver comprises a decider configured to decide a signal before decision to generate a signal after decision, comprising:

• performing non-linear re-distortion processing on the signal after decision according to a first distorter coefficient to generate a first reference signal;
• and
• calculating a second distorter coefficient according to the first reference signal and a 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 used as the first distorter coefficient of the non-linear re-distortion processing in a next update, and the second distorter coefficient is fed back to a non-linear predistorter on an optical transmitter side as a predistortion coefficient of the non-linear predistorter,
• wherein the first distorter coefficient adopted in the non-linear re-distortion processing is a same coefficient as the predistortion coefficient adopted by the non-linear predistorter.

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.