具使用載波聚合的進階型長期演進技術網路中運用深度資訊合成之多視角3D視訊群播

Abstract

隨著近幾年可裸視3D影像的手機設備以及筆記型電腦的出現，提供服務的廠商面臨著如何在長期演進技術升級版網路中傳輸3D影像串流。跟傳統的單視角3D影像不同，多視角3D影像可以提供使用者視角選擇的權利，也可以發展出更多不同的產品，像是自由視角電視。當每一部多視角3D影像的所有視角都被傳送時，提供多視角3D影像的服務可能會超出網路負荷，而深度資訊合成技術使得使用者可以透過鄰近的左邊視角及鄰近的右邊視角去合成出想要觀看的視角，所以一部多視角3D影像中的所有視角不一定要全部被傳送。然而，我們必須小心的選擇傳送的視角以限制影像的失真和最小化頻寬的使用量。 在這篇論文中，我們設計了一個新的最佳化問題，叫做視角及調製編碼格式的選擇問題，去最小化一部多視角3D影像在長期演進技術升級版網路中群播所需要消耗的頻寬，並提出了一個叫做視角及調製編碼格式聚合的演算法，去找出此問題的最佳解。除了頻寬的議題之外，由於多視角3D影像的高資料率，使得資料延遲問題也是相當的重要，而載波聚合技術是一個在長期演進技術升級版網路中常被拿來解決高資料率問題的方法，因此我們另外設計了一個新的NP-hard 問題，叫做視角、調製編碼格式及載波的選擇問題，去最小化一部多視角3D影像利用載波聚合在長期演進技術網路中群播所需要消耗的頻寬，並同時解決資料延遲的問題，我們提出了一個叫做利用調製編碼格式及載波之視角指派的非線性時間演算法，去找出此問題的最佳解，並根據一些特性，提出一個啟發式演算法，並說明它為何為線性時間演算法。最後，從我們的模擬結果可以看出我們的方法在兩個問題中皆可以減少至少百分之二十的頻寬消耗量，且在第二個問題中，我們的方法皆可以解決資料延遲的問題。

With the recent emergence of naked-eye 3D mobile devices and various 3D-enabled laptops, service providers are now faced with the opportunity to provide mobile 3D video streaming in LTE-A networks. Different from traditional single-view 3D videos, multi-view 3D videos allow users to choose preferred view angles and thus are promising for new applications, such as free-viewpoint television (FTV). Enabling multi-view 3D video services may also overwhelm the network when transmitting all views of every video. Fortunately, depth-image-based rendering (DIBR) allows each mobile client to synthesize the desired view from a nearby left view and right view, so that not all views of a video are necessary to be transmitted. Nevertheless, we need to carefully choose the transmitted views to limit the video distortion and minimize the bandwidth consumption. In this thesis, we first formulate a new optimization problem, called View and MCS Selection Problem (VMS) to minimize the bandwidth consumption for multi-view 3D video multicast in LTE-A networks. An algorithm, called View and MCS Aggregation (VMAG) is proposed to find the optimal solution of VMS. Except for the bandwidth issue, the delay problem is also important due to high data rate of multi-view 3D video, and the carrier aggregation (CA) technique is one of choices to be employed to allow user equipment (UE) for high data rate communications in LTE-A networks. Therefore, we further formulate a new NP-hard problem, called View, MCS and Carrier Selection Problem (VMCS) to minimize the bandwidth consumption for multi-view 3D video multicast with CA in LTE-A networks. The optimal solution of VMCS can be found by algorithm, View Assignment with MCS and Carrier (VAMC), with non-polynomial time complexity. Algorithm View and MCS Aggregation with Carrier (VMAGC) is further proposed based on VMAG to effectively find the near optimal solution of VMCS. Simulation results manifest that the bandwidth consumption can be effectively reduced by over 20% in VMS and VMCS, and the transmission time can satisfy the delay constraint of video in VMCS.