title: Experimental demonstration of real-time adaptively modulated DDO-OFDM systems with a high spectral efficiency up to 5.76bit/s/Hz transmission over SMF links.
abstract: In this paper, a FPGAs-based real-time adaptively modulated 256/64/16QAM-encoded base-band OFDM transceiver with a high spectral efficiency up to 5.76bit/s/Hz is successfully developed, and experimentally demonstrated in a simple intensity-modulated direct-detection optical communication system. Experimental results show that it is feasible to transmit a raw signal bit rate of 7.19Gbps adaptively modulated real-time optical OFDM signal over 20km and 50km single mode fibers (SMFs). The performance comparison between real-time and off-line digital signal processing is performed, and the results show that there is a negligible power penalty. In addition, to obtain the best transmission performance, direct-current (DC) bias voltage for MZM and launch power into optical fiber links are explored in the real-time optical OFDM systems.
authors.forename: Ming
authors.initials: M
authors.lastname: Chen
authors.forename: Jing
authors.initials: J
authors.lastname: He
authors.forename: Jin
authors.initials: J
authors.lastname: Tang
authors.forename: Xian
authors.initials: X
authors.lastname: Wu
authors.forename: Lin
authors.initials: L
authors.lastname: Chen