In this paper, we study the optimal transmission of a multi-quality tiled 360 virtual reality (VR) video from a multi-antenna server (e.g., access point or base station) to multiple single-antenna users in a multiple-input multiple-output (MIMO)-orthogonal frequency division multiple access (OFDMA) system. We minimize the total transmission power with respect to the subcarrier allocation constraints, rate allocation constraints, and successful transmission constraints, by optimizing the beamforming vector and subcarrier, transmission power and rate allocation. The formulated resource allocation problem is a challenging mixed discrete-continuous optimization problem. We obtain an asymptotically optimal solution in the case of a large antenna array, and a suboptimal solution in the general case. As far as we know, this is the first work providing optimization-based design for 360 VR video transmission in MIMO-OFDMA systems. Finally, by numerical results, we show that the proposed solutions achieve significant improvement in performance compared to the existing solutions.

中文翻译：

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MIMO-OFDMA系统中多品质平铺360 VR视频的最佳传输

在本文中，我们研究了从多天线服务器（例如，接入点或基站）向多输入多天线中的多个单天线用户的最佳平铺360虚拟现实（VR）视频的最佳传输。输出（MIMO）正交频分多址（OFDMA）系统。通过优化波束赋形矢量和子载波，传输功率和速率分配，我们将与子载波分配约束，速率分配约束和成功的传输约束有关的总传输功率降至最低。制定的资源分配问题是具有挑战性的混合离散连续优化问题。在大天线阵列的情况下，我们获得了渐近最优解，而在一般情况下，我们获得了次优解。据我们所知，这是为MIMO-OFDMA系统中的360 VR视频传输提供基于优化的设计的第一项工作。最后，通过数值结果，我们表明，与现有解决方案相比，所提出的解决方案在性能上有了显着提高。