Point Cloud Soft Multicast for Untethered XR Users
Point Cloud Soft Multicast for Untethered XR Users
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DOI：
10.1109/tmm.2022.3218172
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发表时间：
2023
影响因子：
7.3
通讯作者：
Soushi Ueno;T. Fujihashi;T. Koike-Akino;Takashi Watanabe
中科院分区：
文献类型：
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作者：
Soushi Ueno;T. Fujihashi;T. Koike-Akino;Takashi Watanabe
3D 点云数据格式用于使用 3D 空间中的大量点来表达三维 (3D) 信息。一个关键挑战是在不同的通道质量和可用带宽下为用户提供高质量的 3D 点云，以便在多个不受限制的扩展现实 (XR) 用户之间共享相同的 3D 空间。由于多样性，现有的基于数字的方案面临两个问题：悬崖效应和平稳效应。本文提出了一种针对不受限制的 XR 用户的点云数据软多播方案。该方案的关键思想有三个方面：1）集成图信号处理和模拟调制，根据所有单个 XR 用户的信道质量自适应地提高 3D 重建质量；2）集成吉文斯旋转和非均匀自适应量化，以减少图傅里叶变换的元数据开销；3）优先传输元数据，以根据每个 XR 用户可用的带宽实现自适应质量改进。本文表明，即使 XR 用户体验不同的信道质量，所提出的方案也可以防止悬崖和平稳效应。此外，与带限环境中最先进的基于图的传输方案相比，所提出的传输表现出更好的 3D 重建质量。
3D point cloud data formats are used to express three-dimensional (3D) information using numerous points in a 3D space. A key challenge is the delivery of high-quality 3D point cloud for the users under a diverse channel quality and available bandwidth to share the same 3D space across multiple untethered extended reality (XR) users. The existing digital-based schemes suffer from two issues owing to the diversity: cliff and leveling-off effects. This paper proposes a novel soft multicasting scheme of point cloud data for untethered XR users. The key ideas of the proposed scheme are three-fold: 1) integration of graph signal processing and analog modulation to adaptively improve the 3D reconstruction quality according to the channel quality for all individual XR users, 2) integration of Givens rotation and non-uniform adaptive quantization to reduce metadata overhead for the graph Fourier transform, and 3) prioritized transmission of the metadata to realize adaptive quality improvement based on the bandwidth available for each XR user. This paper reveals that the proposed scheme prevents cliff and leveling-off effects even when the XR users experience different channel qualities. Furthermore, the proposed transmission exhibits better 3D reconstruction quality compared with the state-of-the-art graph-based delivery scheme in band-limited environments.