Bandwidth-Efficient WDM-CAP-PON Using Digital Hilbert Single-Sideband Modulation

We propose a wavelength division multiplexing-carrier-less amplitude/phase modulation-passive optical network (WDM-CAP-PON) downstream with enhanced bandwidth efficiency using low-cost digital Hilbert single-sideband modulation. For each optical subcarrier, there are as many as four 10-Gb/s digital channels carried by a Nyquist subcarrier multiplexing scheme, which can be efficiently generated only using one push-pull Mach-Zehnder modulator (MZM). Compared with the conventional systems with independent optical transmitters and a double-sideband modulation format, the proposed system requires at least four times fewer downlink optical transmitters at the optical line terminal (OLT), which can be translated into savings in cost, power consumption, and footprint, as well as significant mitigation of the power fading effect in fiber transmission.