@INPROCEEDINGS {11273,
author={M. Morant and T. M. F. Alves  and A. Cartaxo and R. Llorente},
booktitle={OSA Optical Fiber Communications - OFC},
title={Transmission impairment compensation using broadband channel sounding in multi-format OFDM-based long-reach PONs},
year={2012},
month={March},
volume={1},
pages={1-3} 
}