Experimental demonstration of channel estimation using image processing in optical direct detection OFDM
In direct detection optical orthogonal frequency division multiplexing (OFDM) system, channel impairments such as residual chromatic dispersion (CD) residual synchronization error, and clock frequency offset induce phase shifts over subcarriers. We propose a method of using image processing for phase channel estimation with negligible overhead which is applicable to various subcarrier modulation formats. We conduct experiment of 32 Gbit/s, 40 Gbit/s, and 48 Gbit/s direct detection optical (DDO) OFDM with 16QAM, 32QAM, and 64QAM subcarrier modulation to verify this method. We investigate the effects of the numbers of required test phases and OFDM symbols with experimental data. We also present an approach to reduce the complexity of this method.
2016 25th Wireless and Optical Communication Conference (WOCC)