Open-Source Software-Based Full-Stack Evaluation Platform of Simplified UTW-OFDM for Beyond 5G

Universal time domain windowed-orthogonal frequency-division multiplexing (UTW-OFDM) effectively suppresses out-of-band emission (OOBE) by applying a UTW to conventional cyclic prefix (CP)-OFDM symbols. This ensures smooth transitions between adjacent OFDM symbols. Previous studies on UTW-OFDM have used computer simulations and software radio-based experiments to evaluate its performance. However, these studies were limited to link-level simulations that considered only physical layer processing and were not evaluated in real-time operation. In this paper, we developed a real-time 5G full-stack evaluation platform for UTW-OFDM using OAI, an open-source 5G platform, to evaluate the feasibility of real-time operation of UTW-OFDM. To integrate UTW-OFDM into the 5G OAI-based evaluation platform, we developed new procedures for generating simplified UTW-OFDM symbols and for adjusting the FFT synchronization position to mitigate windowing effects. The AWGN channel in OAI has also been modified to evaluate its performance based on received signal power. Using the developed platform, we further evaluated the OOBE suppression performance and block error rate (BLER) characteristics of simplified UTW-OFDM emulating an entire 5G system. The results showed that the developed platform effectively suppresses the OOBE by 22dB when applying UTW, while incurring only 0.4 dB signal-to-noise ratio (SNR) degradation to achieve the target BLER of 10
^−l
compared to the CP-OFDM used in conventional 5G. This demonstrates the applicability of UTW-OFDM to Beyond 5G systems, including core networks.