OTA and Hardware-in-the-Loop Testing of an SDR-Based RF Transceiver for 5G Applications

Abstract

Being a fast-growing sphere of wireless communication where 5G reinvents the roadmap, the router of Software-Defined Radio (SDR)-based RF transceiver performance has been of great importance in demonstrating the efficacy of conventional systems and their readiness in meeting the strict standards as expected in the deployment process. Standard RF test techniques usually do not emulate the elaborate, dynamic propagation environments emblematic of 5G trials, especially those associated with the sub-6 GHz frequencies, along with millimeter-wave (mmWave) range. In order to fill this gap, this paper presents an overview of an end-to-end Over-the-Air (OTA) and Hardware-in-the-Loop (HIL) testing system that can combine real-time signal generation, adaptive feedback and channel emulation to test RF transceivers based on SDR technology. The test system is based on Universal Software Radio Peripheral (USRP) X310 platforms to test sub-6 GHz and National Instruments mmWave transceiver platforms to test 28 GHz. The OTA tests are made in both types of testing rooms viz. the anechoic room and reverberation rooms to characterize the system performance within the optimal environment and a multi-path environment. The HIL element, meanwhile, will utilize real-time FPGA based feedback loops that interface with the LabVIEW and MATLAB/Simulink-based environments to test closed-loop communication under closed-loop channel, user mobility and scenario interference by relying on simulated dynamic channel models. The key performance indicators such as Error Vector Magnitude (EVM), Bit Error Rate (BER) and Spectral Emission Compliance and the Beamforming Latency are measured and analyzed with reference to the 3GPP TS 38.104 standard. Findings show that the integrated testbed is an excellent way to capture the responsiveness of the transceiver to changes in the environment, real-time beam-steering, and adaptive modulation and coding scheme validation. Not only the proposed testing plan shortens the validation time, but the accuracy of the prototyping is improved and this testing procedure may be scaled to any complexity while still being cost-effective to test 5G and up-and-coming 6G transceivers before being deployed. The proposed research will also provide a useful validation process to filler the gap that exists between theoretical development of SDRs and practicality in real world performance testing thereby speeding up the realization of intelligent and reconfigurable wireless front-end systems for next generation communication networks.