Future high-speed mobile communication systems require low latency and high capacity networks. Coherent wavelength division multiplexing (WDM) passive optical network (PON) scheme is expected to play a vital role in these systems. In this paper, coherent WDM-PON scheme based on dual-polarization 16-quadrature amplitude modulation (DP-16QAM) transceiver has been investigated. The aim of this scheme is to build a 2 Tbit/s (125 Gbit/s/λ×16 wavelengths) network that will be used in the construction of the transport architecture of fifth generation (5G) and beyond 5G (B5G) cellular networks either in mobile front haul (MFH) or mobile back haul (MBH). The results indicate that the proposed scheme is very adequate for both 5G and B5G cellular networks requirements.