高移动性自由空间光链路中多载波强度调制下的多普勒效应
Doppler Effect in High-Mobility Free Space Optical Links with Multicarrier Intensity Modulation
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中文总结 AI 辅助
本文针对高移动性自由空间光链路，研究了多载波强度调制下的多普勒效应，明确了不同多普勒频移下CPE与ICI的影响，提出需同时进行CPE跟踪和ICI抑制，适用于低轨卫星等场景。
中文摘要 AI 辅助
本文研究了受高移动性影响的强度调制/直接检测（IM/DD）多载波自由空间光链路中，多普勒诱导时间缩放的影响。将多普勒效应建模为施加于解析信号波形的单边带频移，结果表明，即使光电检测去除了光载波相位，该效应仍会产生基带等效相位旋转，进而导致公共相位误差（CPE），以及狄利克雷核引起的载波间干扰（ICI）。基于直流偏置光正交频分复用（DCO-OFDM）的数值结果显示：在小多普勒频移下，CPE分量占主导，可通过导频辅助相位跟踪有效补偿，而诱导的ICI可忽略；在大多普勒频移下，ICI占主导并导致误码率下限，凸显了同时进行CPE跟踪和ICI抑制的必要性，这对具有小子载波间距和大多普勒频移的光链路尤为重要，如低轨卫星对地及星间传输场景。
英文摘要
In this paper, we investigate the impact of Doppler-induced time scaling in intensity-modulation/direct-detection (IM/DD) multicarrier free-space optical links subject to high mobility. Modeling the Doppler effect as a single-sideband frequency shift applied to the analytic signal waveform, we show that it produces a baseband-equivalent phase rotation, resulting in a common-phase error (CPE), in addition to Dirichlet-kernel inter-carrier interference (ICI), even though the optical carrier phase is removed through photo-detection. The numerical results based on DC-biased optical orthogonal frequency-division multiplexing (DCO-OFDM), show that at small Doppler shifts, the CPE component dominates and can be effectively compensated through pilot-aided phase tracking, while the induced ICI remains rather negligible. At larger Doppler shifts, however, ICI becomes dominant and results in a bit-error-rate floor, highlighting the need for both CPE tracking and ICI mitigation. This is particularly relevant for optical links with small subcarrier spacing and large Doppler shifts, such as those in low-Earth-orbit satellite-to-ground and inter-satellite transmission scenarios.
发表机构
- Aix-Marseille University, CNRS, Centrale Med, Fresnel Institute（艾克斯-马赛大学、法国国家科学研究中心、中央理工学院马赛分校、费斯奈尔研究所）
- School of Engineering, the University of Edinburgh（爱丁堡大学工程学院）
机构由 AI 辅助整理，请以论文原文为准。
