1.536-Tb/s CPRI-equivalent rate IFoF mobile fronthaul over a 10 km SSMF with time skew-enabled VSB

Fronthaul plays a crucial role in bridging mobile and optical communications. Conventional digital radio-over-fiber (RoF) systems, utilizing the common public radio interface (CPRI), require a capacity exceeding an order of magnitude above the user data rate, posing challenges for dense small cell deployments and the growing bandwidth demands of 6 G and beyond. Intermediate-frequency-over-fiber (IFoF) with intensity modulation and direct detection (IM/DD) presents a promising alternative due to its high spectral efficiency and simpler architecture. However, traditional IM/DD systems are susceptible to fiber chromatic dispersion, limiting their application in fronthaul. In this Letter, we utilize a time skew-enabled vestigial sideband (VSB) technique to overcome power fading caused by chromatic dispersion in direct detection-based IFoF mobile fronthaul. We experimentally demonstrate hardware-efficient and high-capacity transmission of 1.536-Tb/s CPRI-equivalent rate with 128-QAM signal over a 10-km standard single-mode fiber (SSMF).