Title: Tolerance of Phase Noise in Single-Carrier M-Ary QAM Terahertz Wireless Communications Show Chinese title

Title: 单载波M进制QAM太赫兹无线通信中的相位噪声容限

Abstract: Terahertz wireless communications offer abundant untapped spectrum and are regarded as a promising playground for next-generation high-throughput links. Yet oscillator phase noise becomes the dominant impairment at such high frequencies, severely limiting the reliability of high-order QAM transmission. Here, phase noise is reconstructed from measured spectra and embedded into a single-carrier link model to evaluate its impact. Distinct distortion mechanisms are identified, with slow common phase error and instantaneous phase jitter, where the latter remains as the residual impairment after carrier phase recovery. We further adopt 3{\sigma} error criterion that maps residual distortions onto the constellation, offering a clear and practical indicator of system robustness. The results indicate that modest improvements in oscillator stability translate into significant BER gains without proportional power increase. These findings provide intuitive tolerance of phase noise in M-QAM systems and emphasizes the importance of integrating low-noise photonic oscillators. Show Chinese abstract

Abstract: 太赫兹无线通信提供了丰富的未开发频谱，被认为是下一代高吞吐量链路的有前景的领域。 然而，在如此高的频率下，振荡器相位噪声成为主要的损害因素，严重限制了高阶QAM传输的可靠性。 在此，相位噪声从测量的频谱中重建，并嵌入到单载波链路模型中以评估其影响。 识别出不同的失真机制，包括缓慢的公共相位误差和瞬时相位抖动，其中后者在载波相位恢复后仍作为残余损害存在。 我们进一步采用3{\sigma }误差准则，将残余失真映射到星座图上，提供了一个清晰且实用的系统鲁棒性指标。 结果表明，振荡器稳定性的适度改进可以在不按比例增加功率的情况下带来显著的BER提升。 这些发现提供了对M-QAM系统中相位噪声直观的容限，并强调了集成低噪声光子振荡器的重要性。