Optimal Multi-Quality Multicast for 360 Virtual Reality Video
Optimal Multi-Quality Multicast for 360 Virtual Reality Video
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DOI：
10.1109/glocom.2018.8647429
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发表时间：
2018-12
期刊：
影响因子：
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通讯作者：
Kaixuan Long;Chencheng Ye;Ying Cui;Zhi Liu
中科院分区：
文献类型：
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作者：
Kaixuan Long;Chencheng Ye;Ying Cui;Zhi Liu
一个360度的虚拟现实（VR）视频，记录每个方向感兴趣的场景，为VR用户提供身临其境的观看体验。然而，向移动的用户传输比传统视频大得多的360 VR视频给无线网络带来了沉重的负担。在本文中，我们考虑多质量组播的360 VR视频从一个单一的服务器到多个用户使用时分多址（TDMA）。为了提高传输效率，采用瓦片化，并且每个瓦片被预编码成具有不同质量的多个表示。我们优化的质量水平选择，传输时间分配和传输功率分配，以最大限度地提高所有用户的总效用下的传输时间和功率分配的约束，以及质量平滑度约束的混合质量瓦片。该问题是一个具有挑战性的混合离散-连续优化问题。我们提出了两个低复杂度的算法来获得两个次优解，分别使用连续松弛和DC规划。最后，数值结果表明所提出的解决方案的优势。
A 360 virtual reality (VR) video, recording a scene of interest in every direction, provides VR users with immersive viewing experience. However, transmission of a 360 VR video which is of a much larger size than a traditional video to mobile users brings a heavy burden to a wireless network. In this paper, we consider multi-quality multicast of a 360 VR video from a single server to multiple users using time division multiple access (TDMA). To improve transmission efficiency, tiling is adopted, and each tile is pre-encoded into multiple representations with different qualities. We optimize the quality level selection, transmission time allocation and transmission power allocation to maximize the total utility of all users under the transmission time and power allocation constraints as well as the quality smoothness constraints for mixed-quality tiles. The problem is a challenging mixed discrete-continuous optimization problem. We propose two low-complexity algorithms to obtain two suboptimal solutions, using continuous relaxation and DC programming, respectively. Finally, numerical results demonstrate the advantage of the proposed solutions.