Low-Complexity Non-Integer Fractionally Spaced FIR Filter-Based Electrical Dispersion Pre-Compensation in IM/DD Transmission Systems

Chromatic dispersion (CD) remains a critical challenge for high-speed double-sideband (DSB) intensity modulation and direct detection (IM/DD) systems in the C-band. In this paper, we propose and experimentally demonstrate a low-complexity non-integer fractionally spaced finite-impulse-response filter-based electrical dispersion pre-compensation (NIFS-FIR-pre-EDC) scheme, based on either an offline iterative procedure or a closed-form solution, for high-baud-rate signal transmission in bandwidth-limited IM/DD systems. By operating atK(1KK2/4), but also alleviates the stringent requirements on high sampling rate and wide bandwidth in the digital-to-analog converter (DAC) at the transmitter. Experimental validation in a C-band 100-GBaud on-off keying (OOK) transmission system over 50 km of standard single-mode fibers (SSMF) shows that the proposed 1.2-sps NIFS-FIR-pre-EDC with 901 taps achieves comparable CD pre-compensation performance to the conventional 2-sps FIR-pre-EDC with 1501 taps, while reducing both the RNRM and RNRA by 64%.