Probabilistically Coded Modulation Formats for 5G Mobile Fronthaul Networks

The centralized/cloud radio access network architecture is being considered as a promising solution for fifth-generation cellular networks. In particular, the stringent capacity and latency requirements of the fronthaul segment call for innovations in the design of new architectures and transceivers that support adaptive communication resource allocation between centralized baseband processing units and remote radio heads. In this paper, we propose probabilistically coded three-level pulse amplitude modulation and five-point quadrature amplitude modulation schemes in hybrid mobile fronthaul (MFH) networks that support both coherent detection and direct detection. We propose encoding and decoding algorithms and optimize the decoder configuration through simulations. Based on a distributed pseudorandom encoding technique developed in our earlier work, we adapt the modulation type and code rate per fronthaul connection in real-time. Using two separate software-defined networking enabled downlink and uplink transmission testbeds employing code division multiplexing technology, we demonstrate the benefits of our proposed modulation formats for multicast transmission in hybrid networking scenarios as well as the advantages of adaptive bidirectional transmission in MFH networks.