title: Real-time demonstration of 128-QAM-encoded optical OFDM transmission with a 5.25bit/s/Hz spectral efficiency in simple IMDD systems utilizing directly modulated DFB lasers.
abstract: The feasibility of implementing 128-QAM in off-the-shelf component-based real-time optical OFDM (OOFDM) transceivers incorporating advanced channel estimation, on-line performance monitoring and live parameter optimisation, is experimentally investigated, for the first time, in intensity-modulation and direct-detection (IMDD) single-mode fibre (SMF) and multi-mode fibre (MMF) transmission systems involving directly modulated DFB lasers. The highest ever spectral efficiency of 5.25bit/s/Hz is demonstrated successfully in the aforementioned simple systems. Experimental investigations show that, it is feasible to transmit 5.25 Gb/s 128-QAM-encoded OOFDM real-time signals over 25 km MetroCor(TM) SMFs and 500 m 62.5/125 microm OM1 MMFs. The impact of key parameters on the transmission performance of the real-time OOFDM transceivers with 128-QAM encoding are explored, based on which optimum signal clipping ratios are identified.
authors.affiliation: School of Electronic Engineering, Bangor University, Dean Street, Bangor LL57 1UT, UK.
authors.forename: X Q
authors.initials: XQ
authors.lastname: Jin
authors.forename: R P
authors.initials: RP
authors.lastname: Giddings
authors.forename: E
authors.initials: E
authors.lastname: Hugues-Salas
authors.forename: J M
authors.initials: JM
authors.lastname: Tang
mesh_terms: D003199:Computer Systems; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D055100:Optical Fibers; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*