An Energy-Efficient Concurrent Dual-Band Radio Unit for Neutral Host 5G Open RANs

Reducing transceiver complexity and power consumption is a key design goal for next-generation radio communication systems. This paper presents a dual-band single-chain radio system, leveraging an AMD RFSoC 4x2 Digital Front-End (DFE) and a connectorised Radio Frequency Front-End (RFFE) built with commercial off-the-shelf (COTS) components. The study investigates the impact of power leakage between adjacent bands on system performance through extensive measurements. Results are characterised by error vector magnitude (EVM) and block error rate (BLER) across four modulation schemes.Dual-band performance is evaluated with varying power levels in one band, showing comparable performance between bands when power levels are similar, but degraded sensitivity when power imbalances occur. For comparison, single-band measurements confirm that the dual-band architecture achieves performance parity with single-band setups under equal power conditions. However, the findings highlight the sensitivity of the dual-band system to adjacent-channel interference caused by power leakage, emphasising both its advantages (efficient multiband support with reduced transceiver complexity and power consumption) and its limitations. This work underscores the dual-band architecture as a promising alternative to duplicating radio chains for multi-band operation.