Tap stabilizer method and structure for coherent optical receiver

A method of operating a coherent optical receiver device, the method comprising:

• providing an input signal;
• compensating, by a chromatic dispersion (CD) equalizer module receiving the input signal, for CD affecting the input signal;
• compensating, by a polarization mode dispersion (PMD) equalizer module coupled to the CD equalizer module and having a plurality of PMD taps, for PMD affecting the input signal following the compensation by the CD equalizer module;
• computing, by an evaluation module coupled to the PMD equalizer module, a first sampling phase error (SPE);
• computing, by the evaluation module, a second SPE from the plurality of PMD taps;
• and
• combining, by the evaluation module, the first and second SPE into a total phase error (TPE).

A compensation module configured within a coherent optical receiver, the module comprising:

• a compensated input signal;
• an error evaluation module receiving the compensated input signal, the error evaluation module being configured to compute a first sampling phase error (SPE);
• a timing phase information (TPI) module coupled to the error evaluation module and receiving a plurality of Polarization Mode Dispersion (PMD) taps signals, the TPI module being configured to compute a second SPE from the plurality of PMD taps signals;
• a combining module coupled to the TPI module and the error evaluation module, the combining module being configured to combine the first and second SPE into a total phase error (TPE);
• a timing recovery (TR) filter coupled to the combining module, the TR filter being configured to filter the TPE;
• and
• an interpolated timing recovery (ITR) module coupled to the combining module and receiving the compensated input signal, the ITR module being configured to synchronize the input signal using the TPE.

A method of error compensation by an evaluation module configured within a coherent optical receiver device, the method comprising:

• providing a compensated input signal;
• computing, by an error evaluation module receiving the compensated input signal, a first sampling phase error (SPE);
• computing, by a timing phase information (TPI) module coupled to the error evaluation module and receiving a plurality of Polarization Mode Dispersion (PMD) taps signals, a second SPE from the plurality of PMD taps signals;
• combining, by a combining module coupled to the TPI module and the error evaluation module, the first and second SPE into a total phase error (TPE);
• filtering, by a timing recovery (TR) filter coupled to an interpolated timing recovery (ITR) module and the combining module, the TPE;
• and
• synchronizing, by an ITR module coupled to the PMD equalizer module, the input signal according to the TPE.