NOMA-enabled Cognitive Communication based on Hybrid Narrowband/Wideband SDR Waveform

Software defined radio (SDR) networks are required to achieve endurance, reliability, efficient data transmission, and adaptability to various operating requirements. Their immediate deployment in perilous ventures without the use of any permanent infrastructure has made them an inevitable choice for ad hoc tactical scenarios. The design of SDR waveforms face various challenges due to the rising requirements of cognition and reconfigurability. It is not possible to fulfill these heterogeneous and diverse requirements of quality-of-service (QoS) and range using either of the wideband or narrowband waveforms. This paper proposes an adaptive communication framework for the hybrid narrowband/wideband (NBWB) waveform to meet these requirements. We perform an experimental validation as a proof of concept for the reception of multiple signals by a radio configured in wideband mode. In addition, we develop a hybrid cognitive module (HCM) that is capable of selecting appropriate waveform with suitable system parameters. Owing to the advantages of higher spectral efficiency and user fairness, we propose to leverage non-orthogonal multiple access (NOMA) for parallel transmission from the narrowband waveform users within a single time slot. The numerical results and experimental validation demonstrates the effectiveness of the developed technology in SDR networks.