Nonlinear ISI cancellation in Nyquist-SCM direct detection PON downstream scheme with Volterra pre-equalizer

We propose and experimentally demonstrate a 40-Gbps vestigial-sideband (VSB) Nyquist subcarrier modulation (SCM) direct detection (DD) passive optical network (PON) downstream scheme with Volterra pre-equalizer at optical line terminal (OLT). Volterra pre-equalizer is used to mitigate the fiber dispersion- and square-law detection-induced nonlinear inter-symbol interference (ISI), and thereby improve the receiver sensitivity and reduce the computational complexity of optical network unit (ONU). The 60-km standard single mode fiber (SSMF) transmission experiment results show that 2.1 and 2.8-dB receiver sensitivity improvements are obtained by using the second- and third-order Volterra pre-equalizers, respectively.