20 research outputs found

    MIMO無線伝送に適したスケーラブルビデオコーディングに関する研究

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    Because of the COVID-19 pandemic, a new normal has taken over. It affects the higher demand for using video traffic. H.264/SVC is the video compression standard with several advantages compared with the previous standard, such as a smaller storage space and scalability of video quality depending on network quality. The H.264/SVC bitstream includes one base layer (BL), the most important layer, and one or more enhancement layers (EL) which can be leveraged to optimize the video scalability depending on the network condition and user preferences. The method of transmission is powerful as the video coding method. The transmission of the good video quality will not be effective without a suitable transmission method. In this thesis, we study and research the H.264 scalable video coding transmission with IEEE 802.11ac standard MIMO wireless transmission. We focus on the suitable transmission method for H.264/SVC in a different environment. We divide the research focusing on two issues: 1. With the difference channel environment: The suitable H.264/SVC transmission technique in IEEE 802.11ac with the specific quantization parameter of video encoding was proposed. This aim is to compare three techniques in IEEE 802.11ac: STBC, SISO, and MIMO. In this focus, only the accuracy of the video was considered to measure the efficiency of the transmission technique. This part proposed to utilize STBC to improve the quality of H.264/SVC video transmission. We have shown the performance of H.264/SVC video transmission with three multiple antenna techniques. The results show that STBC is the best technique for H.264/SVC transmission under a low-quality channel environment. The best result shows that STBC in channel model D can improve the PSNR by 67 percent and 76 percent compared with SISO and MIMO, respectively, at low SNR of 20 dB. Due to STBC transmitting multiple copies of data, it can increase data reliability. We proved that STBC is the most suitable multiple antenna technique to improve the quality and realizability of video transmission in both PSNR and bit error rate (BER). 2. With the different transmission distance: H.264/SVC video transmission on MIMO with RSSI feedback was proposed. This aim to proposes the allocation of packetization in the transmission packet and the compromising of quantization parameter encoding both vary on the channel efficiency. This part proposed a MIMO transmission system for H.264 scalable video coding that does not require full CSI feedback. Instead of the CSI feedback, we have used the RSSI and table of encoding rules obtained via link simulation in MATLAB. The encoding rule takes the form of the encoding ratio between the base and enhancement layer, which was done by adjusting the quantization parameter. This proposed system has been shown to improve the PSNR by at least 16 dB and increase the effective distance of 6 meters above compared with the conventional method.九州工業大学博士学位論文 学位記番号:情工博甲第372号 学位授与年月日:令和4年12月27日1 Introduction|2 Video Transmission System Overview|3 H.264/SVC Video Transmission by IEEE 802.11ac Techniques|4 H.264/SVC Video Transmission on MIMO with RSSI Feedback|5 Conclusion and Future Work九州工業大学令和4年

    [[alternative]]System Evaluation, Simulation Platform Set Up and Baseband Circuit Implementation for Wireless Sensor Network

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    計畫編號:NSC93-2213-E032-023研究期間:200408~200507研究經費:515,000[[abstract]]本計畫分三年以實現無線感測網路之系統評估模擬平台建置與基頻電路研製。本計劃研 究子題如下: (A) IEEE 802.15.4 系統之分析及設計 1. 媒介擷取控制層與實體層間之介面設計 2. 系統架構的確定,系統規格及各子方塊之間之介面規格之訂定 3. 低功率基頻電路的設計及探討 4. 接收機技術研究(同步、通道等化、信號偵測等) 5. 利用 ADS 與 Matlab 以建立模擬平台 6. 傳送端與接收端低功率基頻電路之硬體實現 (B) IEEE 802.15.4a 系統之分析及設計 1. UWB 基本原理之研究與探討 2. UWB 傳送與接收基本技術之研究 3. 利用 ADS 及 Matlab 建立模擬平台,對 UWB 之架構模擬 4. UWB 基本方塊規格之訂定 5. 精確定位之研究 (C) IEEE 802.15.4 之MIMO 架構設計 1. MIMO 架構之演算法與架構之研究 2. MIMO 架構之用於IEEE 802.15.4 之通道效應之探討與研究 3. 利用MIMO 架構傳送MPEG-4 之效能探討 4. MIMO 架構之接收技術之研究 5. 利用 ADS 及 Matlab 建立性模擬平台以研究多頻帶的傳輸特性 6. 探討如何利用基頻電路的切換以達低功率而高速的信號傳送 (D) 通道分析及模型的建立 1. 通道傳送損失特性之分析 2. 路徑衰減及多重路徑之分析 3. 路徑衰減之經驗公式推導 4. 通道模型之建立 5. 通道等化器演算法之推導及分析(E) 模擬平台的建立 1. 利用 ADS 程式以建立基頻及 RF 端之模擬平台 2. 利用 Matlab 程式以建立基頻及 RF 端之模擬平台 3. 基頻及 RF 端 ADS 模擬平台的介面設計 4. 基頻及 RF 端 Matlab 模擬平台的介面設計 5. 系統特性的模擬及數據分析 (F) 測試平台的建立 1. IEEE 802.15.4 實體層各子方塊之 Verilog 程式燒錄至 FPGA 並測試 2. IEEE 802.15.4 實體層整合電路之 Verilog 程式燒錄至 FPGA 並測試 3. Mulit-Band 實體層之 Verilog 程式燒錄至 FPGA 並測試 4. IEEE 802.15.4 實體層 ASIC 之測試 5. IEEE 802.15.4 實體層 ASIC 與 RF 之整合測試 6. IEEE 802.15.4 實體層 ASIC 與 MAC 之整合測試 7. IEEE 802.15.4 實體層 ASIC , MAC 及 RF 之整合測試[[sponsorship]]行政院國家科學委員

    Video traffic : characterization, modelling and transmission

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    EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Lightweight mobile and wireless systems: technologies, architectures, and services

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    1Department of Information and Communication Systems Engineering (ICSE), University of the Aegean, 81100 Mytilene, Greece 2Department of Information Engineering and Computer Science (DISI), University of Trento, 38123 Trento, Italy 3Department of Informatics, Alexander Technological Educational Institute of Thessaloniki, Thessaloniki, 574 00 Macedonia, Greece 4Centre Tecnologic de Telecomunicacions de Catalunya (CTTC), 08860 Barcelona, Spain 5North Carolina State University (NCSU), Raleigh, NC 27695, US

    Slight-Delay Shaped Variable Bit Rate (SD-SVBR) Technique for Video Transmission

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    The aim of this thesis is to present a new shaped Variable Bit Rate (VBR) for video transmission, which plays a crucial role in delivering video traffic over the Internet. This is due to the surge of video media applications over the Internet and the video typically has the characteristic of a highly bursty traffic, which leads to the Internet bandwidth fluctuation. This new shaped algorithm, referred to as Slight Delay - Shaped Variable Bit Rate (SD-SVBR), is aimed at controlling the video rate for video application transmission. It is designed based on the Shaped VBR (SVBR) algorithm and was implemented in the Network Simulator 2 (ns-2). SVBR algorithm is devised for real-time video applications and it has several limitations and weaknesses due to its embedded estimation or prediction processes. SVBR faces several problems, such as the occurrence of unwanted sharp decrease in data rate, buffer overflow, the existence of a low data rate, and the generation of a cyclical negative fluctuation. The new algorithm is capable of producing a high data rate and at the same time a better quantization parameter (QP) stability video sequence. In addition, the data rate is shaped efficiently to prevent unwanted sharp increment or decrement, and to avoid buffer overflow. To achieve the aim, SD-SVBR has three strategies, which are processing the next Group of Picture (GoP) video sequence and obtaining the QP-to-data rate list, dimensioning the data rate to a higher utilization of the leaky-bucket, and implementing a QP smoothing method by carefully measuring the effects of following the previous QP value. However, this algorithm has to be combined with a network feedback algorithm to produce a better overall video rate control. A combination of several video clips, which consisted of a varied video rate, has been used for the purpose of evaluating SD-SVBR performance. The results showed that SD-SVBR gains an impressive overall Peak Signal-to-Noise Ratio (PSNR) value. In addition, in almost all cases, it gains a high video rate but without buffer overflow, utilizes the buffer well, and interestingly, it is still able to obtain smoother QP fluctuation

    Smart PIN: performance and cost-oriented context-aware personal information network

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    The next generation of networks will involve interconnection of heterogeneous individual networks such as WPAN, WLAN, WMAN and Cellular network, adopting the IP as common infrastructural protocol and providing virtually always-connected network. Furthermore, there are many devices which enable easy acquisition and storage of information as pictures, movies, emails, etc. Therefore, the information overload and divergent content’s characteristics make it difficult for users to handle their data in manual way. Consequently, there is a need for personalised automatic services which would enable data exchange across heterogeneous network and devices. To support these personalised services, user centric approaches for data delivery across the heterogeneous network are also required. In this context, this thesis proposes Smart PIN - a novel performance and cost-oriented context-aware Personal Information Network. Smart PIN's architecture is detailed including its network, service and management components. Within the service component, two novel schemes for efficient delivery of context and content data are proposed: Multimedia Data Replication Scheme (MDRS) and Quality-oriented Algorithm for Multiple-source Multimedia Delivery (QAMMD). MDRS supports efficient data accessibility among distributed devices using data replication which is based on a utility function and a minimum data set. QAMMD employs a buffer underflow avoidance scheme for streaming, which achieves high multimedia quality without content adaptation to network conditions. Simulation models for MDRS and QAMMD were built which are based on various heterogeneous network scenarios. Additionally a multiple-source streaming based on QAMMS was implemented as a prototype and tested in an emulated network environment. Comparative tests show that MDRS and QAMMD perform significantly better than other approaches

    Video Packet Scheduling With Stochastic QoS for Cognitive Heterogeneous Networks

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    Cross-layer analysis for video transmission over COFDM-based wireless local area networks

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    EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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