Probabilistic shaping of quadrature amplitude modulation (QAM) is used to enhance the sensitivity of an optical communication system. Sensitivity gains of 0.43 and 0.8 dB are demonstrated in back-to-back experiments by the shaping of 16QAM and 64QAM, respectively. Furthermore, numerical simulations are used to prove the robustness of probabilistic shaping to a mismatch between the constellation used and the signal-to-noise ratio (SNR) of the channel. It is found that, accepting a 0.1-dB SNR penalty, only four shaping distributions are required to support these gains for 64QAM.
- Achievable information rates
- digital coherent transceivers
- digital signal processing
- mutual information
- probabilistic shaping
- signal shaping
Fehenberger, T., Lavery, D., Maher, R., Alvarado, A., Bayvel, P., & Hanik, N. (2016). Sensitivity gains by mismatched probabilistic shaping for optical communication systems. IEEE Photonics Technology Letters, 28(7), 786-789. https://doi.org/10.1109/LPT.2015.2514078