Presentation Information
[7p-N321-8]Tolerance of Phase Noise in 64QAM THz Wireless Links
〇(P)Bowen LIU1, Takasumi Tanabe1 (1.Keio University)
Keywords:
terahertz wireless communication,phase noise,microcomb
The rapid growth of the mobile digital economy has triggered an explosive demand for wireless data traffic. Fast, stable, affordable, and accessible connectivity is increasingly essential for inclusive societal and individual development. Terahertz (THz) wireless communication is a promising solution for next-generation high-speed, near-filed links due to its largely untapped ultra-wide bandwidth. Most THz systems rely on photonic heterodyning of laser diodes, but their free-running nature introduces significant phase noise, necessitating stabilization via PLLs or external cavities. Microcombs, generated in high-Q microresonators, offer superior coherence and integrability, and have demonstrated 10-Tbps transmission in comb-driven links. Yet a systematic analysis of phase noise tolerance remains lacking, creating obstacles for the development of robust physical-layer protocols. Here, we quantitatively investigate the impact of phase noise on THz wireless communication systems and determine its tolerance thresholds. We characterize the phase noise of three representative local oscillators (LOs), demonstrating the great advantage of microcombs in high-speed, low-error tasks using advanced modulation formats beyond 64QAM. Considering the 3σ coverage (99.7% distribution)—the EVM must remain below 5.12% to achieve error-free transmission for 64QAM. Furthermore, EVM exhibits an approximately linear correlation with phase noise standard deviation, yielding a tolerance threshold of STD = 0.042 for error-free 64QAM transmission.