Pulse position modulation (PPM) is introduced downstream of the reflective semiconductor optical amplifier (RSOA)-based single-fiber full-duplex bidirectional wavelength division multiplex passive optical network (WDM PON) to suppress the interference brought by the remodulation effect in the RSOA, Rayleigh backscattering, and reflection of the connection devices. In addition, because of the power-efficient characteristic of the PPM-encoded signals, the power budget shows clear improvement. As t
