Open-Source Software-Based gNB Prototype for Highly Spectral-Efficient Private 5G System

In this paper, we developed and demonstrated a highly spectral-efficient private 5G standalone system using open-source 5G software and software-defined radio. We introduced an innovative waveform shaping technique for downlink (DL) transmissions and a dynamic bandwidth adaptation scheduler for uplink (UL) communications within the 5G base station. These methods substantially reduce out-of-band emissions (OOBE), making high-speed transmission possible even under stringent interference requirements, with only a minimal 18% throughput reduction and no need for device modifications. Notably, our developed prototype ensures complete compatibility with existing 5G systems, allowing commercial off-the-shelf devices, such as smartphones, to connect seamlessly. Experiments in an anechoic chamber using a smartphone have shown that high-data-rate transmission (240.5 Mbps at DL and 43.9 Mbps at UL) can be achieved while suppressing OOBE by 25dB at DL and 11dB at UL.