Wide-range Frequency Offset Estimator For Dsp-based Optical Coherent Receivers

We propose a hardware-efficient, feed-forward, wide-range frequency offset estimator for DSP-based optical coherent receivers, employed in 112 Gb/s PM-QPSK systems. This estimator is capable to estimate offsets in a range of ±5 GHz, using a simple relationship of signal spectrum. The obtained results show that this estimator is robust to spectrum asymmetry caused by electrical and optical filtering of the signal, even when using return-to-zero signals. © 2011 IEEE.710713Ribeiro, V.B., (2010) Digital Polarization Tracking Algorithms for 100 Gb/s Coherent DP-QPSK Transmission, , MOMAG, Vila VelhaDiniz, J.C.M., (2010) 112 Gb/s Co-DP-QPSK Optical Transmission: Offline Digital Filtering Analysis, , MOMAG, Vila VelhaRibeiro, V.B., Digital filtering algorithms for 112 Gb/s Co-DP-QPSK optical transmission OSA the Latin America Optics and Photonics Conference, Recife, 2010Optical Internetworking Forum, Integrable Tunable Laser Assembly MSA (OIF-ITLA-MSA-01.1), Nov.25, 2005Leven, A., Kaneda, N., Koc, U.-V., Chen, Y.-K., Frequency estimation in intradyne reception (2007) IEEE Photonic Technology Letters, 19 (6), pp. 366-368Hoffmann, S., Frequency and phase estimation for coherent QPSK transmission with unlocked DFB lasers (2008) IEEE Photonic Technology Letters, 20 (18), pp. 1569-1571Morelli, M., Mengali, U., Feedforward frequency estimation for PSK: A tutorial review (1998) Eur. Trans. Tel., 9 (2), pp. 103-116Li, L., Tao, Z., Oda, S., Hoshida, T., Rasmussen, J.C., Wide-range, accurate and simple digital frequency offset compensator for optical coherent receivers Optical Fiber Conference, OWT4, San Diego, 2008Li, Z., Wide-range and fast-convergence frequency offset estimator by BER-aiding for optical coherent receivers OSA Asia Communications and Photonics Conference, ThT2, Shangai, 2009Zhang, S., Dual-stage cascaded frequency offset estimation for digital coherent receivers (2010) IEEE Photonic Technology Letters, 22 (6), pp. 401-403Nakagawa, T., Wide-range and fast-tracking frequency offset estimator for optical coherent receivers European Conference on Optical Comunications, We.7.A.2, Torino, 2010Tibuleak, S., Filer, M., Transmission impairments in DWDM networks with reconfigurable optical add-drop multiplexers (2010) IEEE Journal of Lightwave Technology, 28 (4), pp. 557-568Ip, E., Kahn, J.M., Power spectra of return-to-zero optical signals (2006) IEEE Journal of Lightwave Technology, 24 (3), pp. 1610-161