We describe the design of a trained and pilot-aided digital coherent receiver, capable of detecting a 1 Tb/s superchannel with a single optical front-end. Algorithms for receiver training are described, which calculate the equalizer coefficients, subchannel SNRs, and centroids of the transmitted constellations. Algorithms for pilot-aided operation are then described in detail, providing pilot-aided constant modulus equalization and joint carrier-phase estimation over several coherent subchannels. We demonstrate the detection of a superchannel with net bit rate in excess of 1 Tb/s with a single coherent receiver. An 11 × 10 GBd DP-64QAM Nyquist superchannel is used, with 1.32 Tb/s gross bit rate.
- Carrier phase estimation
- coherent detection
Millar, D. S., Maher, R., Lavery, D., Koike-Akino, T., Pajovic, M., Alvarado, A., Paskov, M., Kojima, K., Parsons, K., Thomsen, B. C., Savory, S. J., & Bayvel, P. (2016). Design of a 1 Tb/s superchannel coherent receiver. Journal of Lightwave Technology, 34(6), 1453-1463. https://doi.org/10.1109/JLT.2016.2519260