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Dissertations / Theses on the topic 'Multiplexed Wireless Video Transmission'
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1
Zhao, Shengjie. "Video transmission over wireless networks." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/2225.
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Compressed video bitstream transmissions over wireless networks are addressed in this work. We first consider error control and power allocation for transmitting wireless video over CDMA networks in conjunction with multiuser detection. We map a layered video bitstream to several CDMA fading channels and inject multiple source/parity layers into each of these channels at the transmitter. We formulate a combined optimization problem and give the optimal joint rate and power allocation for each of linear minimum mean-square error (MMSE) multiuser detector in the uplink and two types of blind linear MMSE detectors, i.e., the direct-matrix-inversion (DMI) blind detector and the subspace blind detector, in the downlink. We then present a multiple-channel video transmission scheme in wireless CDMA networks over multipath fading channels. For a given budget on the available bandwidth and total transmit power, the transmitter determines the optimal power allocations and the optimal transmission rates among multiple CDMA channels, as well as the optimal product channel code rate allocation. We also make use of results on the large-system CDMA performance for various multiuser receivers in multipath fading channels. We employ a fast joint source-channel coding algorithm to obtain the optimal product channel code structure. Finally, we propose an end-to-end architecture for multi-layer progressive video delivery over space-time differentially coded orthogonal frequency division multiplexing (STDC-OFDM) systems. We propose to use progressive joint source-channel coding to generate operational transmission distortion-power-rate (TD-PR) surfaces. By extending the rate-distortion function in source coding to the TD-PR surface in joint source-channel coding, our work can use the ??equal slope?? argument to effectively solve the transmission rate allocation problem as well as the transmission power allocation problem for multi-layer video transmission. It is demonstrated through simulations that as the wireless channel conditions change, these proposed schemes can scale the video streams and transport the scaled video streams to receivers with a smooth change of perceptual quality.
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Soloperto, Raffaele <1981>. "Video transmission over wireless channel." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3439/1/Soloperto_Raffaele_tesi.pdf.
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This work has been realized by the author in his PhD course in Electrical, Computer Science and Telecommunication at the University of Bologna, Faculty of Engineering, Italy. All the documentation here reported is a summary of years of work, under the supervision of Prof. Oreste Andrisano, coordinator of Wireless Communication Laboratory - WiLab, in Bologna. The subject of this thesis is the transmission of video in a context of heterogeneous network, and in particular, using a wireless channel.
All the instrumentation that has been used for the characterization of the telecommunication systems belongs to CNR (National Research Council), CNIT (Italian Inter-
University Center), and DEIS (Dept. of Electrical, Computer Science, and Systems).
From November 2009 to July 2010, the author spent his time abroad, working in collaboration with DLR - German Aerospace Center in Munich, Germany, on channel
coding area, developing a general purpose decoder machine to decode a huge family of iterative codes.
A patent concerning Doubly Generalized-Low Density Parity Check codes has been produced by the author as well as some important scientic papers, published on
IEEE journals and conferences.
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Soloperto, Raffaele <1981>. "Video transmission over wireless channel." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3439/.
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This work has been realized by the author in his PhD course in Electrical, Computer Science and Telecommunication at the University of Bologna, Faculty of Engineering, Italy. All the documentation here reported is a summary of years of work, under the supervision of Prof. Oreste Andrisano, coordinator of Wireless Communication Laboratory - WiLab, in Bologna. The subject of this thesis is the transmission of video in a context of heterogeneous network, and in particular, using a wireless channel.
All the instrumentation that has been used for the characterization of the telecommunication systems belongs to CNR (National Research Council), CNIT (Italian Inter-
University Center), and DEIS (Dept. of Electrical, Computer Science, and Systems).
From November 2009 to July 2010, the author spent his time abroad, working in collaboration with DLR - German Aerospace Center in Munich, Germany, on channel
coding area, developing a general purpose decoder machine to decode a huge family of iterative codes.
A patent concerning Doubly Generalized-Low Density Parity Check codes has been produced by the author as well as some important scientic papers, published on
IEEE journals and conferences.
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Ghassemlooy, Z. T. "Optical fibre transmission of Multiplexed video signals using pulse width modulations." Thesis, University of Manchester, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380313.
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Wu, Xiao Wen. "Video transmission over wireless CDMA networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0026/MQ27027.pdf.
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Zammit, Saviour. "Digital video transmission over wireless networks." Thesis, Aston University, 1995. http://publications.aston.ac.uk/8058/.
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The advent of the Integrated Services Digital Network (ISDN) led to the standardisation of the first video codecs for interpersonal video communications, followed closely by the development of standards for the compression, storage and distribution of digital video in the PC environment, mainly targeted at CD-ROM storage. At the same time the second-generation digital wireless networks, and the third-generation networks being developed, have enough bandwidth to support digital video services. The radio propagation medium is a difficult environment in which to deploy low bit error rate, real time services such as video. The video coding standards designed for ISDN and storage applications, were targeted at low bit error rate levels, orders of magnitude lower than the typical bit error rates experienced on wireless networks. This thesis is concerned with the transmission of digital, compressed video over wireless networks. It investigates the behaviour of motion compensated, hybrid interframe DPCM/DCT video coding algorithms, which form the basis of current coding algorithms, in the presence of high bit error rates commonly found on digital wireless networks. A group of video codecs, based on the ITU-T H.261 standard, are developed which are robust to the burst errors experienced on radio channels. The radio link is simulated at low level, to generate typical error files that closely model real world situations, in a Rayleigh fading environment perturbed by co-channel interference, and on frequency selective channels which introduce inter symbol interference. Typical anti-multipath techniques, such as antenna diversity, are deployed to mitigate the effects of the channel. Link layer error control techniques are also investigated.
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Wu, Xiao Wen Carleton University Dissertation Engineering Systems and Computer. "Video transmission over wireless CDMA networks." Ottawa, 1997.
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Dani, Janak. "Transmission distortion modeling for wireless video communication." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/5845.
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Thesis (M.S.)--University of Missouri-Columbia, 2005.<br>The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (January 22, 2007) Includes bibliographical references.
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Tesanovic, Milos. "Robust wireless MIMO transmission of video using multiple descriptions." Thesis, University of Bristol, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486399.
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Recent research has devised a way of increasing the achievable data rates for wireless communication by deploying multiple antennas at the transmitter and receiver, thereby creating multiple paths between the two ends of the system. This technique is known as MIMO (multiple-input-multiple-output) and its inclusion into the forthcoming wireless standards is already under way. Because of the promised increase in spectral efficiency, MIMO technology holds great appeal for bandwidth-hungry multimedia transmission. Conventional, single-description coding schemes (SDC), coupled with generic data transmission techniques (packet demultiplexing onto the created sub-channels) are shown in this thesis to yield unsatisfactory results, failing to harness the potential benefits arising from MIMO. As a way of remedying the underlying mapping problem, this thesis proposes the use of multiple-description coding (MDC) as a suitable video decomposition, with compelling results achieved for a wide range ofMIMO techniques and channel conditions. In the first instance, video transmission over MIMO systems that employ singular value decomposition (SVD) is studied and comparisons between SDC and proposed MDC are performed. MIMO-SVD systems are straightforward to simulate and provide greater mapping flexibility. The promising performance of MDC is then further enhanced by investigating power allocation in MIMO-SVD systems. Inspired by the water-filling power allocation strategy, results demonstrate that further improvements over SDC are possible if, for low SNRs, the stronger sub-channel is boosted at the expense of the weaker channel. For high SNR values, the converse is true. Using the underpinning multiple channels to send independent streams of data is known as spatial multiplexing (SM) and SVD is one way of achieving this. Various other SM techniques that do not require prior channel knowledge-CSI-at the transmitter exist and they are studied and compared with SVD in the context of video quality. The spatial correlation is changed by varying the angular width at the transmitter and receiver, with a view to emulating a wide range of possible deployment scenarios. Although not optimal for the entire range of SNR values studied, SVD dominates other SM techniques under study and it is therefore of great interest to investigate the effects of CSI latency in SVD systems. These are quantified and the severe degradation when CSI latency cannot be ignored is tackled. Analytical results justify the deployment of SVD even when prior CSI is not perfect, as it facilitates post-processing that is shown to restore results similar to those obtained when prior CSI is perfect. No study of MIMO systems would be complete without investigating possible improvements from space-time (ST) techniques. Even though SM seems an obvious choice for video transmission as it offers the much-needed increase in throughput, it is shown in this thesis that simple MIMO-STBC systems, while not offering any increase in spectral efficiency compared to SISO systems, can outperform SM systems in the presence of errors because of their superior error performance at low SNR. When SDC is used to transmit video over SM, the improvements from multiplexing are only visible in the quasi error-free range of SNR values. MDC is demonstrated to move the SMlSTBC cross-over point towards the region of lower SNR values, reducing the penalty that has to be paid for the higher throughput offered by SM systems. MDC is shown to equally be able to improve the performance of STBC systems by interleaving the descriptions prior to transmission. Further improvements arising from the use of cross-packet FEC are achieved. However, interleaving incurs delays that may not be acceptable. These delays are therefore quantified for different interleaving scenarios. It is shown that MDC can help reduce the decoding delays, while at the same time offering improvements not possible from SDC interleaving, with or without FEC.
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Sgardoni, Victoria. "Enhanced wireless video transmission using a cross-layer design." Thesis, University of Bristol, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.574424.
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The increasing demand for video services over wireless LANs and mobile broad- band networks and the challenges wireless video transmission is facing, drives the need to improve the support for video services over these networks. The aim of this thesis is to design and quantify the benefits of new methods that optimise end-to-end wireless video delivery via generic cross-layer design. These new ar- chitectures encourage complex interactions between the PRY/MAC layers of the wireless system and the application layer of the video services. Wireless networks are fundamentally error-prone due to the time varying nature of the radio channel while video services are typically intolerant to data loss. To improve data reliab- ility wireless networks offer forward error correction (FEC), such as the recently proposed application layer FEC based on Raptor codes, and ARQ packet retrans- mission at the PRY and MAC layers respectively. The performance of the WiFi ARQ mechanism is studied in terms of packet loss and packet delay, using time-correlated packet errors generated from a time- varying channel model. It is shown that prior simulations assuming uncorrelated errors seriously under predict the packet loss rate and latency resulting from ARQ retransmissions. The work in this thesis then focuses on the transmission of video over a mobile WiMAX network. The ARQ mechanism of mobile WiMAX is studied in terms of packet loss rate and latency. The properties and benefits of Raptor codes are then explored. In particular, interactions between the mobile WiMAX Modulation and Coding Scheme, the Raptor block size and the Raptor code rate are explored (for various Doppler spreads) via Monte Carlo simulation. This thesis proposes a novel cross-layer design with tight coupling between formats and packets across the OSI layers. A new methodology based on "Raptor- aware" link adaptation is proposed to select the optimum pairs of MCS mode and Raptor code rate in order to maximise transmission efficiency while maintaining a required level of PER at the application layer. Simulation results show that the proposed methodology significantly reduces the required radio resources, whilst offering error free communication to the video layer. To achieve these gains it is shown that MAC SDUs with missing ARQ blocks must be delivered to the higher layers. This can be achieved with the introduction of a permeable layer into the standard OSI model. Simulations show that to achieve the same level of video performance a standard mobile WiMAX system (at low mobile speeds) requires 118% more bandwidth at an SNR of 18dB, dropping to 40% at 16dB SNR. The proposed design also offers an SNR gain of 4dB which can extend the range of video services (particularly useful for multicast transmissions).
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Mansour, Hassan Bader. "Modeling of scalable video content for multi-user wireless transmission." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/12550.
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This thesis addresses different aspects of wireless video transmission of scalable video content to multiple users over lossy and under-provisioned channels. Modern wireless video transmission systems, such as the Third Generation Partnership Project (3GPP)'s high speed packet access (HSPA) networks and IEEE 802.11-based wireless local area networks (WLANs) allow sharing common bandwidth resources among multiple video users. However, the unreliable nature of the wireless link results in packet losses and fluctuations in the available channel capacity. This calls for flexible encoding, error protection, and rate control strategies implemented at the video encoder or base station.
The scalable video coding (SVC) extension of the H.264/AVC video standard delivers quality scalable video bitstreams that help define and provide quality of service (QoS) guarantees for wireless video transmission applications. We develop real-time rate and distortion estimation models for the coarse/medium granular scalability (CGS/MGS) features in SVC. These models allow mobile video encoders to predict the packet size and corresponding distortion of a video frame using only the residual mean absolute difference (MAD) and the quantization parameter (QP).
This thesis employs different cross layer resource allocation techniques that jointly optimize the video bit-rate, error protection, and latency control algorithms in pre-encoded and real-time streaming scenarios. In the first scenario, real-time multi-user streaming with dynamic channel throughput and packet losses is solved by controlling the base and enhancement layer quality as well as unequal erasure protection (UXP) overhead to minimize the frame-level distortion. The second scenario considers pre-encoded scalable video streaming in capacity limited wireless channels suffering from latency problems and packet losses. We develop a loss distortion model for hierarchical predictive coders and employ dynamic UXP allocation with a delay-aware non-stationary rate-allocation streaming policy. The third scenario addresses the problem of efficiently allocating multi-rate IEEE 802.11-based network resources among multiple scalable video streams using temporal fairness constraints. We present a joint link-adaptation at the physical (PHY) layer and a dynamic packet dropping mechanism in the network or medium access control (MAC) layer for multi-rate wireless networks. We demonstrate that these methods result in significant performance gains over existing schemes.
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Barmada, Bashar. "Reliable wireless transmission of priority coded image and video services." Thesis, University of Essex, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418336.
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Connie, Ashfiqua Tahseen. "Efficient transmission of error resilient H.264 video over wireless links." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/1979.
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With the advent of telecommunication technology, the need to transport multimedia content is increasing day by day. Successful video transmission over the wireless network faces a lot of challenges because of the limited resource and error prone nature of the wireless environment. To deal with these two challenges, not only the video needs to be compressed very efficiently but also the compression scheme needs to provide some error resilient features to deal with the high packet loss probability. In this thesis, we have worked with the H.264/ Advanced Video Coding (AVC) video compression standard since this is the most recent and most efficient video compression scheme. Also H.264 provides novel error resilient features e.g. slicing of the frame, Flexible Macroblock Ordering (FMO), data partitioning etc.
In this thesis, we investigate how to utilize the error resilient schemes of H.264 to ensure a good quality picture at the receiving end. In the first part of the thesis, we find the optimum slice size that will enhance the quality of video transmission in a 3G environment. In the second part, we jointly optimize the data partitioning property and partial reliability extension property of the new transport layer protocol, Stream Control Transmission Protocol (SCTP). In the third and last part, we focus more on the network layer issues. We obtain the optimum point of application layer Forward Error Correction (FEC) and Medium Access Control (MAC) layer retransmission in a capacity constrained network. We assume that the bit rate assigned for the video application is more than the video bit rate so that the extra capacity available can be used for error correction.
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Bocus, Mohammud Zubeir. "Resource allocation for scalable video transmission over next-generation wireless networks." Thesis, University of Bristol, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.566697.
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Advancements in broadband wireless networks and video compression tech- nologies have led to a tremendous increase in the demand for wireless multimedia services over recent years. Popular wireless transmission techniques enabling en- hanced throughput include orthogonal frequency division multiplexing (OFDM) while the recent video coding standard, namely the H.264/ AYC, enables up to twice the compression efficiency to be attained relative to previous video com- pression techniques. Regardless of these developments, the highly dynamic and unpredictable nature of wireless channels, along with the requirements for main- taining the quality of service (Q08) and seamless video playback for all users, impose severe constraints on the design of wireless multimedia systems. A video coding technique that has been developed for such environments is the scalable video coding (8YC), which allows parts of the encoded bitstream to be discarded in response to a drop in the channel quality. However, state-of-the-art resource allocation techniques for SYC transmission over the wireless medium suffer from high computational complexity. Low-complexity, sub-optimal alternatives, on the other hand, are not always adequate. Given the sparse nature of spectrum resources, and the paradigm shift in spectrum access with the advent of cognitive radio systems, it is evident that sub-optimal algorithms having large optimality gaps are not desired. In fact, such approaches would be in contradiction to the definition of spectrum efficient, cognitive radio systems. In this thesis, resource allocation schemes for the transmission of H.264 SYC over wireless networks are investigated. In particular, OFDM systems are consid- ered, including OFDM-based cognitive radio networks. Cross-layer optimisation techniques for fine grain scalable (FGS) video sequences are analysed. Although the problem is initially non-convex and has non-polynomial-time (NP) complex- ity, low complexity techniques are derived that lead to solutions very close to the optimal. Resource allocation schemes for coarse grain scalable (CGS) and medium grain scalable (MGS) sequences over OFDM-based cognitive systems are also investigated. As opposed to FGS, CGS/MGS do not allow an encoded bitstream to be truncated at random bit location. Consequently, new methods are derived that focus on this particular type of video coding. The presence of multiple antennas at the cognitive transmitter and their effect on the aggregate visual quality of all secondary users are also discussed. Furthermore, a joint call admission control (CAC) and resource allocation for the transmission of CGS and MGS video sequences over orthogonal frequency division multiple access (OFDMA) are analysed. This scheme considers the sce- narios where the available channel resources are not enough to support the video data of all users. Finally, rate-adaptation techniques for scalable video transmission over wire- less networks are presented. Rate-adaptation refers to the methods by which the encoding parameters of the video coding are adapted in response to the chan- nel conditions. Interestingly, it is shown that under a given channel condition, increasing the granularity of a scalable sequence lead to diminishing returns in terms of the rate achieved. Moreover, the transmission of scalable sequences over cognitive radio networks where perfect channel knowledge is not available is investigated. The effect of the granularity of the bitstream on the interference observed by incumbent users is also presented. It is shown that the probability of exceeding the interference threshold can be significantly reduced by proper specification of the video encoding parameters.
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Chen, Chao. "Adaptive Video Transmission over Wireless Channels with Optimized Quality of Experiences." Thesis, The University of Texas at Austin, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3690944.
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<p>Video traffic is growing rapidly in wireless networks. Different from ordinary data traffic, video streams have higher data rates and tighter delay constraints. The ever-varying throughput of wireless links, however, cannot support continuous video playback if the video data rate is kept at a high level. To this end, adaptive video transmission techniques are employed to reduce the risk of playback interruptions by dynamically matching the video data rate to the varying channel throughput. In this dissertation, I develop new models to capture viewers' quality of experience (QoE) and design adaptive transmission algorithms to optimize the QoE. The contributions of this dissertation are threefold. </p><p> First, I develop a new model for the viewers' QoE in rate-switching systems in which the video source rate is adapted every several seconds. The model is developed to predict an important aspect of QoE, the time-varying subjective quality (TVSQ), i.e., the up-to-the-moment subjective quality of a video as it is played. I first build a video database of rate-switching videos and measure TVSQs via a subjective study. Then, I parameterize and validate the TVSQ model using the measured TVSQs. Finally, based on the TVSQ model, I design an adaptive rate-switching algorithm that optimizes the time-averaged TVSQs of wireless video users. </p><p> Second, I propose an adaptive video transmission algorithm to optimize the Overall Quality (OQ) of rate-switching videos, i.e., the viewers' judgement on the quality of the whole video. Through the subjective study, I find that the OQ is strongly correlated with the empirical cumulative distribution function (eCDF) of the video quality perceived by viewers. Based on this observation, I develop an adaptive video transmission algorithm that maximizes the number of video users who satisfy given constraints on the eCDF of perceived video qualities. </p><p> Third, I propose an adaptive transmission algorithm for scalable videos. Different from the rate-switching systems, scalable videos support rate adaptation for each video frame. The proposed adaptive transmission algorithm maximizes the time-averaged video quality while maintaining continuous video playback. When the channel throughput is high, the algorithm increases the video data rate to improve video quality. Otherwise, the algorithm decreases the video data rate to buffer more videos and to reduce the risk of playback interruption. Simulation results show that the performance of the proposed algorithm is close to a performance upper bound. </p>
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Yang, Guanghua. "Adaptive unequal error protection for wireless video transmissions." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B37153791Bib.
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Yang, Guanghua, and 楊光華. "Adaptive unequal error protection for wireless video transmissions." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B37153791.
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Li, Shuang Lim Alvin S. "Improving throughput of video streaming in wireless sensor networks." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Computer_Science_and_Software_Engineering/Thesis/Li_Shuang_55.pdf.
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Adam, Evangelos A. "Transmission of low-bit-rate MPEG-4 video signals over wireless channels." Thesis, Monterey, Calif. Naval Postgraduate School, 2002. http://hdl.handle.net/10945/6099.
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The objective of this thesis is to study the performance of the MPEG-4 video coding standard in the presence of highly erroneous media, such as a wireless channel. MPEG-4 treats video sequences as a collection of objects rather than a collection of frames. A Matlab encoder that conforms to this approach is built for compressing raw video signals at various compression rates. A two-state Markov channel was used to simulate a wireless channel that introduces errors in the video bitstream and a decoder that utilizes error concealment techniques to hide these errors from the user was used to reconstruct the video sequence. The error resilient tools that the MPEG-4 standard provides to enhance the robustness in the presence of errors were simulated and proven to be advantageous compared to methods used in previous standards (MPEG-2, H.263, etc.). At the decoder, the use of error concealment techniques significantly enhanced the quality of the reconstructed video in high bit error rate environments.
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Appuhami, Ralalage Harsha Nishantha Deepal. "Cross-layer design for scalable/3D wireless video transmission over IP networks." Thesis, Kingston University, 2014. http://eprints.kingston.ac.uk/30012/.
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The first two parts of the thesis address the issues related to 3D video transmission over wireless networks and proposes cross-layer design techniques to optimise the information exchange between dif- ferent Open Systems Interconnection (OSI) layers or system blocks. In particular, the first section of this thesis exploits the flexibility of adjusting the checksum coverage length of the transport layer pro- tocol, UDP-lite as opposed to its counterpart UDP. The study pro- poses an optimum checksum coverage length to protect only impor- tant header information of an H.264 encoded video transmission over wireless links, together with robust header compression (RoHC) and Automatic Retransmission Request (ARQ). The second part of the thesis investigates a content and Channel aware Medium Access Con- trol (MAC) layer scheduling algorithm by considering the layer prior- ities of an H.264 Scalable Video Coding (SVC) encoded 3D video transmission over an Orthogonal Frequency Division Multiple Ac- cess (OFDMA) based wireless link with a prioritised queuing tech- nique to improve the Quality of Experience (QoE) of the end users. A considerable amount of research time was devoted to investigat- ing accurate, consistent and real-time quality evaluation techniques for 3D image/ video as cross-layer design techniques mostly rely on the quality feedbacks from end users to optimise system parameters. The first quality metric proposed is a stereoscopic image quality met- ric using the disparity histogram of the left and right views. A 3D stereoscopic video quality evaluation technique is proposed, based on the predominant energy distribution of gradients using 3D structural tensors in the next section. Finally, a near no reference quality metric is proposed for colour plus depth 3D video compression and transmis- sion, using the extracted edge information of colour images and depth maps. The research investigates a number of error resilient transmission methods to combat artifacts in 3D video delivery over wireless chan- nels. A Region-of-Interest (ROI) based transmission method for stereo- scopic videos has been proposed to mark the important areas of the video and provide Unequal Error Protection (UEP) during transmis- sion. Next, we investigate the effects of compression and packet loss on the rendered video quality and propose a model to quantify ren- dering and concealment errors at the sender-side and then use the information generated through the model to effectively deliver 3D. Finally an asymmetric coding approach is suggested for 3D medical video transmitted over band limited wireless networks by considering large data rates associated with 3D medical video as they are usually captured in high resolution and pixel depth. Key words: 3D video transmission, Cross-layer design, Orthogonal frequency-division multiple access, H.264 video compression, Scalable video coding, Robust header compression, automatic retransmission request, Quality of experience, Prioritized 3D video transmission, Un- equal error protection.
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Montes, Luis Roger Atero. "Resilient evolutionary source coding for wireless mobile TV/video image communication systems." Thesis, Staffordshire University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311039.
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Shen, Yushi. "Cross-layer bandwidth allocation and delay allocation for video transmission over wireless channels." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3221812.
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Thesis (Ph. D.)--University of California, San Diego, 2006.<br>Title from first page of PDF file (viewed September 18, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 143-146).
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Ferré, Pierre. "Cross-layer analysis for video transmission over COFDM-based wireless local area networks." Thesis, University of Bristol, 2006. http://hdl.handle.net/1983/6f02ae0e-1db0-4d4f-afb9-8f359af4eb46.
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Lee, Sanghoon. "Foveated video compression and visual communications over wireless and wireline networks /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
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Ibrahim, Abdulkareem B. "Error resilience and concealment in MVC video over wireless networks." Thesis, Brunel University, 2015. http://bura.brunel.ac.uk/handle/2438/10484.
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Multi-view video is capable of presenting a full and accurate depth perception of a scene. The concept of multi-view video is becoming more useful especially in 3D display systems by enhancing the viewing of high resolution stereoscopic images from arbitrary viewpoints without the use of any special glasses. Like monoscopic video, the multi-view video is faced with different challenges such as: reliable compression, storage and bandwidth due to the increased number of views as well as the high sensitivity to transmission errors. All these may lead to a detrimental effect on the reconstructed views. The work in this thesis investigates the problems and challenges of transmission losses in a multi-view video bitstream over error prone wireless networks. Based on the network simulation results, the proposed technique is capable of addressing the problem of transmission losses. In practical wireless networks, transmission errors are inevitable and pose a serious challenge to the coded video data. The aim of this research effort is to examine the effect of these errors in a multi-view video bitstream when transmitted over a lossy channel. Moreover, this research work aims to develop a novel scheme that can make the multi-view coded videos more robust to transmission errors by minimizing the error effects and improving the perceptual quality. Multi-layer data partitioning as an error resilient technique is developed in JMVC 8.5 reference software in order to make the multi-view video bitstream more robust during transmission. In addition to that, we propose a simple decoding scheme that can support the decoding of the multi-layer data partitioning bitstream over channels with high error rate. The proposed technique is benchmarked with the already existing H.264/AVC data partitioning technique. The work in this thesis also employs the use of group of pictures as a coding parameter to investigate and reduce the effects of transmission errors in multi-view video transmitted over a very high error rate channel. The experiments are carried out with different error loss rates in order to evaluate the performance of these techniques in terms of perceptual quality when transmitted over a simulated erroneous channel. Errors are introduced using the Sirannon network simulator. The error performance of each technique is evaluated and analysed both objectively and subjectively after reconstruction. The results of the research investigation and simulation are presented and analysed in chapter six of the thesis.
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Durso, Christopher M. "A ROBUST DIGITAL WIRELESS LINK FOR TACTICAL UAV’S." International Foundation for Telemetering, 2003. http://hdl.handle.net/10150/606695.
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International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada<br>Tactical unmanned aerial vehicles (UAV’s) can deliver real-time battlefield video directly to the soldier providing unprecedented situational awareness. The video communications system must be compact, lightweight, secure, and easy to deploy without a complicated ground station. Pacific Microwave Research, Inc. is developing a system capable of providing reliable and secure video communications to handheld terminals throughout the theater. PMR’s Coded Orthogonal Frequency Division Multiplex (COFDM) video transmission system is designed for tactical video transmission in battlefield or Military Operations in Urban Terrain (MOUT) environments. Using digital modulation coding, the system provides a very robust link in the mobile environment.
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Cai, Jianfei. "Robust error control and optimal bit allocation for image and video transmission over wireless channels /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3052158.
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Wong, Chi-wah Alec, and 王梓樺. "Exploiting wireless link adaptation and region-of-interest processing to improve real-time scalable video transmission." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B29804152.
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Takacs, Edward, Christopher M. Durso, and David Dirdo. "A ROBUST DIGITAL WIRELESS LINK FOR TACTICAL UAV’S." International Foundation for Telemetering, 2005. http://hdl.handle.net/10150/604917.
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ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada<br>A conventionally designed radio frequency amplifier operated in its linear region exhibits
low DC to RF conversion efficiency. Typically, for a power amplifier designed for digital
modulation applications, the amplifier is operated “backed-off” from its P1dB point by a factor of 10
or -10 dB. The typical linear amplifier is biased for either Class A or Class A/B operation
depending on the acceptable design trade-offs between efficiency and linearity between these two
methods. A novel design approach to increasing the efficiency of a linear RF power amplifier using
a modified Odd-Way Doherty technique is presented in this paper. The design was simulated, built
and then tested. The design yields improvements in efficiency and linearity.
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Halbach, Till. "Error-robust coding and transformation of compressed hybered hybrid video streams for packet-switched wireless networks." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Information Technology, Mathematics and Electrical Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-136.
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<p>This dissertation considers packet-switched wireless networks for transmission of variable-rate layered hybrid video streams. Target applications are video streaming and broadcasting services. The work can be divided into two main parts.</p><p>In the first part, a novel quality-scalable scheme based on coefficient refinement and encoder quality constraints is developed as a possible extension to the video coding standard H.264. After a technical introduction to the coding tools of H.264 with the main focus on error resilience features, various quality scalability schemes in previous research are reviewed. Based on this discussion, an encoder decoder framework is designed for an arbitrary number of quality layers, hereby also enabling region-of-interest coding. After that, the performance of the new system is exhaustively tested, showing that the bit rate increase typically encountered with scalable hybrid coding schemes is, for certain coding parameters, only small to moderate. The double- and triple-layer constellations of the framework are shown to perform superior to other systems.</p><p>The second part considers layered code streams as generated by the scheme of the first part. Various error propagation issues in hybrid streams are discussed, which leads to the definition of a decoder quality constraint and a segmentation of the code stream to transmit. A packetization scheme based on successive source rate consumption is drafted, followed by the formulation of the channel code rate optimization problem for an optimum assignment of available codes to the channel packets. Proper MSE-based error metrics are derived, incorporating the properties of the source signal, a terminate-on-error decoding strategy, error concealment, inter-packet dependencies, and the channel conditions. The Viterbi algorithm is presented as a low-complexity solution to the optimization problem, showing a great adaptivity of the joint source channel coding scheme to the channel conditions. An almost constant image qualiity is achieved, also in mismatch situations, while the overall channel code rate decreases only as little as necessary as the channel quality deteriorates. It is further shown that the variance of code distributions is only small, and that the codes are assigned irregularly to all channel packets.</p><p>A double-layer constellation of the framework clearly outperforms other schemes with a substantial margin. </p><p>Keywords — Digital lossy video compression, visual communication, variable bit rate (VBR), SNR scalability, layered image processing, quality layer, hybrid code stream, predictive coding, progressive bit stream, joint source channel coding, fidelity constraint, channel error robustness, resilience, concealment, packet-switched, mobile and wireless ATM, noisy transmission, packet loss, binary symmetric channel, streaming, broadcasting, satellite and radio links, H.264, MPEG-4 AVC, Viterbi, trellis, unequal error protection</p>
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Ribeiro, Thatiane Cristina dos Santos de Carvalho 1982. "Analise de desempenho de transmissão de video em redes IEEE 802.11 visando a estruturação de canais de retorno para TV digital." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261690.
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Orientador: Yuzo Iano<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação<br>Made available in DSpace on 2018-08-12T15:19:02Z (GMT). No. of bitstreams: 1
Ribeiro_ThatianeCristinadosSantosdeCarvalho_M.pdf: 2904973 bytes, checksum: e3c67793847764cf8eac05c50f45b48f (MD5)
Previous issue date: 2008<br>Resumo: A transmissão de vídeo em redes Wireless é abordada pela pesquisa, devido o grande aumento na utilização dessas redes na ultima década. O acesso à banda larga por essas redes é feito de forma eficiente, rápida e com baixo custo de implementação e manutenção da rede. A motivação para o desenvolvimento é utilizar essas redes e a rede IPTV para promover a interatividade e uma forma do canal de retorno para Sistemas de Televisão Digital, que estão sendo implementadas atualmente no Brasil. O canal de Retorno da TV Digital é importante para o sistema, pois um dos objetivos é prover a interatividade entre os usuários. Isso deve ser feito de forma simples com baixo custo e com tecnologia compatível a região do usuário. A simulação trata de um sistema de transmissão unicast que seria semelhante a uma interatividade local e dedicada. O usuário transmite o conteúdo de uma só vez. Os dados que são transmitidos pela provedora de serviços, são armazenados no set-top-box, e só são modificados em caso de novo fluxo de dados, quando há atualização ou acesso a nova área de serviços. Os testes feitos durante a pesquisa, transmitem conteúdo em tempo real e avaliam de forma quantitativa o desempenho das redes IEEE 802.11b e IEEE 802.11g.<br>Abstract: The streaming video transmission on Wireless networks is concerned in the research due to the large increase in the use of such networks in the last decade. Broadband access for these networks is made efficiently, quickly and with low implementation and maintenance costs of the network. The motivation for developing this research is to use these networks and IPTV network to promote interactivity and a return channel for digital television system, currently being implemented in Brazil. The return channel is important for the Digital TV system, because one of the goals is to provide interactivity for the users. This should be done in a simple, low cost way and with technology compatible in the region of the user. The simulation deals with a unicast transmission system which is similar to a local and dedicated interactivity. The user transmits all the contents at once. The data transmitted by a service provider are stored on set-top box and are modified only in case of new data flow, when there are updates or access to new area of services. The tests performed during the research, it was broadcasted contents in real time and evaluated quantitative the performance of IEEE 802.11b and IEEE 802.11g networks.<br>Mestrado<br>Telecomunicações e Telemática<br>Mestre em Engenharia Elétrica
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Ramadan, Wassim. "Amélioration de la transmission de contenus vidéo et de données dans les réseaux sans-fil." Phd thesis, Université de Franche-Comté, 2011. http://tel.archives-ouvertes.fr/tel-00802909.
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Cette thèse traite de l'amélioration du transfert de données, d'une part sur les réseaux sans-fils et d'autre part pour des données continues telles que la vidéo. Pour améliorer les transmissions sur les réseaux sans-fils nous nous sommes intéressés au contrôle de congestion des protocoles de transport mais nous avons également proposé une méthode pratique d'adaptation de la vidéo aux conditions du réseau.Cette thèse contient donc deux volets. La première porte sur la différenciation de pertes entre les pertes de congestion et les pertes sur le réseau sans fil. Il est connu que lors d'une perte, les protocoles de transport actuels réduisent le débit (par deux par exemple). Or, pour les pertes sans fil, cela n'a pas d'intérêt. Pour différencier ces pertes sur l'émetteur des données, nous proposons une méthode originale qui utilise à la fois ECN (Explicit Congestion Notification) et le changement sur le RTT du paquet qui suit la perte. La seconde propose une méthode originale d'adaptation vidéo au niveau de la couche application sur l'émetteur. Avec l'arrivée des vidéos à bitrate élevés (HD, 3D) et l'augmentation constante mais irrégulière des bandes passantes réseau, la qualité vidéo à l'utilisateur reste à la traîne : elle est non-optimale (bitrate beaucoup plus petit ou plus grand que le débit disponible) et non adaptable (aux conditions dynamiques du réseau). Nous proposons une méthode très simple à implémenter, puisqu'elle ne requiert qu'une modification côté émetteur au niveau de la couche application. Elle adapte en permanence le bitrate de la vidéo aux conditions du réseau, autrement dit elle fait un contrôle de congestion sur l'émetteur. La visioconférence est un cas d'application idéal. Cette méthode fonctionne au-dessus de tout protocole de transport avec contrôle de congestion (TCP, DCCP), ce qui lui confère aussi la propriété de TCP-friendliness.
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Jao, Li-Shian, and 饒力先. "Regulation of video rate in a multiplexed transmission." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/34749412236082574711.
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碩士<br>國立交通大學<br>電信研究所<br>82<br>This thesis examines the problem of video transmission in a
multiplexed environment over ATM network under the constraints
of channel bandwidth and MPEG-based codec. Leaky bucket model
for burst rate control of video transport over ATM net using
MPEG-based compression codec has been proven effective. Network
buffer placement is adopted to effectively allocate network
chann bandwidth in a multiplexed environment. To improve the
system performace, criterion to minimize the bursty probability
and buffer overlap is used to allocate multiplexer buffer to
each user according to the source characteristics and the total
number of sources being served. We show that the Fourier
analysis method is effective in network buffer placement, and a
control scheme under joint considerations of leaky bucket model
and network buffer management is proposed to improve system
performace.
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Xiang, Siyuan. "Scalable video transmission over wireless networks." Thesis, 2013. http://hdl.handle.net/1828/4485.
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With the increasing demand of video applications in wireless networks, how to
better support video transmission over wireless networks has drawn much
attention to the research community. Time-varying and error-prone nature of
wireless channel makes video transmission in wireless networks a challenging
task to provide the users with satisfactory watching experience. For different
video applications, we choose different video coding techniques accordingly.
E.g., for Internet video streaming, we choose standardized H.264 video codec;
for video transmission in sensor networks or multicast, we choose simple and
energy-conserving video coding technique based on compressive sensing. Thus, the
challenges for different video transmission applications are different.
Therefore, This dissertation tackles video transmission problem in three
different applications.
First, for dynamic adaptive streaming over HTTP (DASH), we investigate the
streaming strategy. Specifically, we focus on the rate adaptation algorithm for
streaming scalable video (H.264/SVC) in wireless networks. We model the rate
adaptation problem as a Markov Decision Process (MDP), aiming to find an optimal
streaming strategy in terms of user-perceived quality of experience (QoE) such
as playback interruption, average playback quality and playback smoothness. We
then obtain the optimal MDP solution using dynamic programming. However, the
optimal solution requires the knowledge of the available bandwidth statistics
and has a large number of states, which makes it difficult to obtain the optimal
solution in real time. Therefore, we further propose an online algorithm which
integrates the learning and planning process. The proposed online algorithm
collects bandwidth statistics and makes streaming decisions in real time. A
reward parameter has been defined in our proposed streaming strategy, which can
be adjusted to make a good trade-off between the average playback quality and
playback smoothness.We also use a simple testbed to validate our proposed
algorithm.
Second, for video transmission in wireless sensor networks, we consider a
wireless sensor node monitoring the environment and it is equipped with a
compressive-sensing based, single-pixel image camera and other sensors such as
temperature and humidity sensors. The wireless node needs to send the data out
in a timely and energy efficient way. This transmission control problem is
challenging in that we need to jointly consider perceived video quality, quality
variation, power consumption and transmission delay requirements, and the
wireless channel uncertainty. We address the above issues by first building a
rate-distortion model for compressive sensing video. Then we formulate the
deterministic and stochastic optimization problems and design the transmission
control algorithm which jointly performs rate control, scheduling and power
control.
Third, we propose a low-complex, scalable video coding architecture based on
compressive sensing (SVCCS) for wireless unicast and multicast transmissions.
SVCCS achieves good scalability, error resilience and coding efficiency. SVCCS
encoded bitstream is divided into base and enhancement layers. The layered
structure provides quality and temporal scalability. While in the enhancement
layer, the CS measurements provide fine granular quality scalability. We also
investigate the rate allocation problem for multicasting SVCCS encoded bitstream
to a group of receivers with heterogeneous channel conditions. Specifically, we
study how to allocate rate between the base and enhancement layer to improve the
overall perceived video quality for all the receivers.<br>Graduate<br>0984<br>siyxiang@ece.uvic.ca
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Bansal, Manu. "Optimal scalable video transmission over wireless networks." 2007. http://proquest.umi.com/pqdweb?did=1397913381&sid=10&Fmt=2&clientId=39334&RQT=309&VName=PQD.
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Thesis (Ph.D.)--State University of New York at Buffalo, 2007.<br>Title from PDF title page (viewed on Feb. 14, 2008) Available through UMI ProQuest Digital Dissertations. Thesis adviser: Kondi, Lisimachos P. Includes bibliographical references.
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Chen, Shao-Wei, and 陳紹偉. "Video Packetization and Adaptive ARQ for Video Transmission over Wireless LAN." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/12089456433613151776.
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碩士<br>國立中央大學<br>電機工程研究所<br>91<br>With the technology advances in digital compression and wireless networks, real-time streaming of video content over IEEE 802.11 wireless networks is a multimedia application full of potentials. However, unlike wired packet switched networks, IEEE 802.11 wireless networks are relatively unreliable due to an error prone physical channel and the lack of QoS guarantee. Therefore, the video quality transmitting over wireless networks will possibly be degraded.
In the thesis, we propose a priority video packetization mechanism and an adaptive ARQ scheme according to video packet priorities to reduce the degradation in wireless networks. At the video encoder, the priority video packetization mechanism sets the video packet size base on the video types. Namely, the packet size is reduced for important video frames to reduce packet losses when transmitting over severely interfered wireless channels. The adaptive ARQ in the IEEE 802.11 point coordinator adapts the repeat limits depend on the wireless channel condition and video packet priorities to achieve both high channel utilization and good video quality. Simulation results show that with five error patterns and four video sequences, the proposed mechanism indeed achieves reduction of lost video packets and protection of important video packets within the delay constraint. The proposed mechanisms can improve the PSNR by 3dB on average under wireless channels with a mean burst error length 10 bits at the range of bit error rate from 3×10^-4 to 5×10^-4.
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Jubran, Mohammad K. "Efficient video transmission over wireless multiple antenna systems." 2007. http://proquest.umi.com/pqdweb?did=1397913371&sid=4&Fmt=2&clientId=39334&RQT=309&VName=PQD.
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Thesis (Ph.D.)--State University of New York at Buffalo, 2007.<br>Title from PDF title page (viewed on Feb. 21, 2008) Available through UMI ProQuest Digital Dissertations. Thesis adviser: Kondi, Lisimachos P. Includes bibliographical references.
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Abdel, Khalek Amin Nazih. "Cross-layer perceptual optimization for wireless video transmission." 2013. http://hdl.handle.net/2152/22898.
Full textAbstract:
Bandwidth-intensive video streaming applications occupy an overwhelming fraction of bandwidth-limited wireless network traffic. Compressed video data are highly structured and the psycho-visual perception of distortions and losses closely depends on that structure. This dissertation exploits the inherent video data structure to develop perceptually-optimized transmission paradigms at different protocol layers that improve video quality of experience, introduce error resilience, and enable supporting more video users.
First, we consider the problem of network-wide perceptual quality optimization whereby different video users with (possibly different) real-time delay constraints are sharing wireless channel resources. Due to the inherently stochastic nature of wireless fading channels, we provide statistical delay guarantees using the theory of effective capacity. We derive the resource allocation policy that maximizes the sum video quality and show that the optimal operating point per user is such that the rate-distortion slope is the inverse of the supported video source rate per unit bandwidth, termed source spectral efficiency. We further propose a scheduling policy that maximizes the number of scheduled users that meet their QoS requirement.
Next, we develop user-level perceptual quality optimization techniques for non-scalable video streams. For non-scalable videos, we estimate packet loss visibility through a generalized linear model and use for prioritized packet delivery. We solve the problem of mapping video packets to MIMO subchannels and adapting per-stream rates to maximize the total perceptual value of successfully delivered packets per unit time. We show that the solution enables jointly reaping gains in terms of improved video quality and lower latency. Optimized packet-stream mapping enables transmission of more relevant packets over more reliable streams while unequal modulation opportunistically increases the transmission rate on the stronger streams to enable low latency delivery of high priority packets.
Finally, we develop user-level perceptual quality optimization techniques for scalable video streams. We propose online learning of the mapping between packet losses and quality degradation using nonparametric regression. This quality-loss mapping is subsequently used to provide unequal error protection for different video layers with perceptual quality guarantees. Channel-aware scalable codec adaptation and buffer management policies simultaneously ensure continuous high-quality playback. Across the various contributions, analytic results as well as video transmission simulations demonstrate the value of perceptual optimization in improving video quality and capacity.<br>text
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Lin, Jun-Lin, and 林君臨. "3-D PAC Video Codec for Wireless Transmission." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/77608378984769447788.
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碩士<br>國立交通大學<br>電子工程系<br>87<br>To overcome the bandwidth limitation and to strengthen the channel effect immunity, a cube-based polynomial video coding scheme for mobile radio transmission is derived, named Three Dimensional Polynomial Approximation Coding (3-D PAC). It also possesses the features of low bit rate of transmission data, robustness for channel fading and simple computation scheme for real-time processing. Compared with the videophone standard H.261, it gains advantage on resisting channel noise to 3 dB with the same bit rate, and the superior subjective performance may be obtained. The hardware complexity of 3-D PAC is 80% of general MPEG2 implementation, while the PSNR of 3-D PAC is even superior to that of MPEG2 by 4.5dB. The simulations of wireless transmission as well as hardware simulation are attached.
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Borges, Pedro Miguel Faria. "Mechanisms for resilient video transmission in wireless networks." Master's thesis, 2014. http://hdl.handle.net/10316/35666.
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Dissertação de Mestrado em Engenharia Informática apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra<br>Remote video viewing is largely growing, especially in wireless devices. Therefore,
video transmission mechanisms such as retransmission and Forward Error
Correction (FEC) are very important to ensure that the video arrives at its destination
while retaining its quality. While some of these mechanisms can obtain
good performance, this does not mean they provide an optimal situation. There
are several factors that negatively impact Quality of Experience (QoE) in video
transmission, such as network congestion, loss and type of video being transmitted.
Adaptive Forward Error Correction schemes aim at providing protection against
loss errors by analysing several relevant characteristics of the video and/or network,
and using them to apply unequal error protection (UEP) to di erent parts
of the video. Taking this into account, it is clear that an adaptive FEC mechanism
is a viable option to achieve optimal error protection, thus increasing the video
transmission's resilience against errors and losses, and therefore improving Quality
of Experience for the end user.
This work presents and examines the state-of-the-art mechanisms for retransmission,
FEC, QoE, video classi cation and algorithm optimization. The assessment
of the mechanisms presents an in-depth study of each concept and individually
explores their advantages and disadvantages. Three mechanisms which
provide adaptive FEC are developed in and evaluated in a simulation environment,
with motion classi cation, error correction, adaptive redundancy allocation
and loss feedback components. The capabilities of the adaptive FEC mechanisms
are evaluated through a wireless network environment in order to assess their
performance against other methods.
The results obtained through the assessed mechanisms showed incremental
improvements through each stage of development. They also showed that it is
possible to accurately characterize the intensity of motion in video sequences according
to their characteristics. Furthermore, the ndings highlight the importance
of shielding sequences with higher amounts of motion intensity with greater
quantities of redundancy due to david their higher degradation when subjected to
error. The mechanisms achieved a considerable reduction in the amount of redundancy
used to shield the data being transmitted, particularly the loss prediction
mechanism. At the same time, the mechanisms maintained video quality which
combined with the overhead reduction results in an overall improvement of QoE
ultimately enhancing video transmission in wireless networks.
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SHIH, CHUAN-YU, and 施權祐. "Remote Wireless Transmission Technology of Controllable Video Streaming." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/7sx832.
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碩士<br>國立臺北科技大學<br>電子工程系<br>107<br>In today's increasingly unmanned Aerial Vehicle (UAV) generations, many ideas can be used to replace human labor with UAVs, such as large-scale farmland spraying pesticides, bridge detect, disaster relief , etc. However, the flight life is the most fatal shortcoming of UAV. Because that the drone has been flying several times in order to collect different data, resulting in add to manpower and time cost. So it is worthwhile to develop a system that can control the UAV to read different data streams and return it to the base control station, achieve efficiency of collecting data is improved.
This article will use the software define radio and peripheral equipment design and build the uplink with the backhaul control signal mechanism, and integrate with the video streaming transmission technology into a two-way communication system. First, we will discuss the problems with practical development, and select appropriate modulation technology and be compatible with the original communication system. Then, the signals sent by different sequences correspond to their respective control behaviors, and the control flow is used to select the current data stream to be acquired and the modulation used for video streaming transmission, thereby improving the work efficiency and flexibility of the UAV. At the end of the article, it will actually test the two-way communication system in outdoors. It is verified that the communication system with control mechanism can be realized and applied in various fields.
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Liu, Tsu-Ming, and 劉子明. "Soft Variable Length Decoding for the Wireless Video Transmission." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/pts6gk.
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碩士<br>國立交通大學<br>電子工程系所<br>92<br>Variable Length Codes (VLCs) are extensively used in recent video and image coding standard. However, traditional table look-up hard decoding may lose synchronization and induce error propagation over a noisy channel. To improve the error resilience of VLC, more and more researchers pay lots of attention about the joint source and channel design. The soft VLC decoding method has emerged to resist the channel disturbances on the environment of band-limited and broadcasting system. Such design generally needs to maintain many states when the table size grows. Hence, soft VLC decoders have problems of high complexity and high memory access.
To reduce the table size and the number of memory access, we propose a soft VLC decoder with low memory access and low complexity approach. Further, a novel measurement of “symbol-alias” is presented to provide more accurate performance estimation. With the proposed Black-Box model, we can achieve the optimal trade-off between performance and complexity.
Finally, a memory-efficient and low-complexity soft VLC decoder using performance modeling is proposed. It exploits not only modified sorting scheme to reduce the memory access, but also table redundancy to reduce the table size at the cost of minor performance loss. The system evaluation is achieved in the model of MPEG-4/UDP-Lite/UEP/AWGN. We averagely improve the PSNR by 0.4~2.9dB (i.e. 40~80% improvement) and offer better subjective quality compared with the traditional VLC decoding and standard-support RVLC decoding.
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Shih, Chi-Huang, and 施啟煌. "Study on DCCP-based Video Transmission over Wireless Internet." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/29142633665074959986.
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博士<br>國立成功大學<br>電機工程學系碩博士班<br>97<br>This dissertation develops a video transmission system based on datagram congestion control protocol (DCCP) to transport real-time streaming video over wireless Internet and focuses on MPEG-4 video in realizing the system design. The main challenge of the DCCP-based video system is to integrate the system components such as the source coding, channel coding and packetization strategy, with new DCCP features including TCP-friendly rate control (TFRC) and partial checksum coverage for wireless video coding and transmission. TFRC is a congestion control mechanism designed for multimedia flows and aims to benefit the Internet-based video streaming by adapting the system transmission rate to the network congestion level in a TCP-friendly manner to reduce the potential packet loss and delays. On the other hand, the partial checksum coverage allows DCCP to forward the error-corrupted packets instead of dropping them and accordingly facilitates the error-resilient source coding to increase video goodput. In addressing the practical difficulties involved in integrating video system components in the application domain with DCCP in the transport domain, this dissertation presents a DCCP-based video transport architecture for wireless video with emphasis on adaptive source coding and efficient packetization.
Delivering DCCP-based video over the wireless Internet primarily requires the rate matching between the source/channel coding and TFRC transport service to ensure TCP-friendliness. In addition to the rate matching requirement, users demand a high-quality, smooth media output under the varying network conditions. Accordingly, an integrated rate control scheme is first proposed to meet the rate matching with the controlled transmission buffering delay and reduce the frame skipping. Also, DCCP/TFRC flows with variable packet size are beneficial to robust video transmission in the wireless environment but adversely affect the TCP-friendliness feature. Without adapting packet size to the varying channel errors, we present an in-packet segmentation scheme to virtually divide the DCCP packet into segments, and recover the erroneous segments through the MAC-level retransmissions. As a result, the proposed in-packet segmentation scheme is more efficient in data recovery over wireless channels while preserving the TCP-friendliness of DCCP-based video flows. The extensive experiment results have demonstrated the utility of the two proposed schemes under the varying network conditions. Through the successful system integration, the developed DCCP-based video system better preserves the motion smoothness, and improves the overall perceptual quality for wireless video transmissions to obtain a smooth, high visual quality video experience.
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Ochieng, Ojwang Dan. "Power control for video transmission over Wireless mesh networks." 2011. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000402.
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M. Tech. Electrical Engineering.<br>Proposes a power control algorithm for video transmission over WMNs. The proposed algorithm is implemented and simulation results compared with those of conventional IEEE 802.11b network.
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Wen, Jen-hsiao, and 溫仁孝. "Dynamic Resource Allocation of Video Transmission over Wireless Networks." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/46601030483892083221.
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碩士<br>國立成功大學<br>電腦與通信工程研究所<br>96<br>Video transmission plays an important role in wireless communication. For resource allocation mechanism, it needs to support quality of service (QoS). We calculate channel distortion of each layer in Scalable Video Coding (SVC) as a new parameter for resource allocation mechanism. We employ adaptive modulation and coding (AMC) scheme for wireless channel at the physical layer. Then the resource allocation mechanism we designed is suitable for the time-varying wireless channel and the characteristic of video streaming.
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Chung, Yi-Wei, and 鍾議葳. "Wireless Video Transmission Techniques on MPEG-4 Streaming System." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/85117465386562516289.
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碩士<br>國立成功大學<br>資訊工程學系碩博士班<br>92<br>Due to the fast progress of wireless technology in recent years, the software and hardware of wireless network becomes more and more popular, such as IEEE 802.11x, Bluetooth, and 3G. People can use the handheld devices, such as PDA and Smart Phone to access the resources of Internet(e.g., text, image, music, movie, and even online games)through the wireless network. Among the above applications, viewing the movie with the Multimedia Streaming techniques, usually encounters two main problems of wireless network：low bandwidth and error prone. Hence, the quality of playback degrades seriously. In order to solve these two problems, MPEG(Moving Picture Experts Group)proposed the all new digital compression techniques－MPEG-4. First, we can take advantage of the high compression ratio of MPEG-4 to decrease the data rate of movie. Hence, the bandwidth requirement is solved. On the other side, we can also use the error resilient tools to decrease the impact of high error rate.
The applied network environment in this thesis is the popular Wireless LAN－IEEE 802.11b. Besides, the applied audio/video codec is MPEG-4(ISO/IEC 14496), and we use the IETF(Internet Engineering Task Force)based streaming solutions, such as RTP (Real Time Transport Protocol) and RTSP(Real Time Streaming Protocol) to construct the Wireless Streaming System.
Furthermore, we proposed the GOP based packet interleaving scheme to reach to the error spreading effect. Based on the interleaving scheme and MPEG-4 error resilient tools, we can get better playback quality on wireless network.
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Chen, Chao active 2013. "Adaptive video transmission over wireless channels with optimized quality of experiences." 2013. http://hdl.handle.net/2152/23203.
Full textAbstract:
Video traffic is growing rapidly in wireless networks. Different from ordinary data traffic, video streams have higher data rates and tighter delay constraints. The ever-varying throughput of wireless links, however, cannot support continuous video playback if the video data rate is kept at a high level. To this end, adaptive video transmission techniques are employed to reduce the risk of playback interruptions by dynamically matching the video data rate to the varying channel throughput. In this dissertation, I develop new models to capture viewers' quality of experience (QoE) and design adaptive transmission algorithms to optimize the QoE. The contributions of this dissertation are threefold.
First, I develop a new model for the viewers' QoE in rate-switching systems in which the video source rate is adapted every several seconds. The model is developed to predict an important aspect of QoE, the time-varying subjective quality (TVSQ), i.e., the up-to-the-moment subjective quality of a video as it is played. I first build a video database of rate-switching videos and measure TVSQs via a subjective study. Then, I parameterize and validate the TVSQ model using the measured TVSQs. Finally, based on the TVSQ model, I design an adaptive rate-switching algorithm that optimizes the time-averaged TVSQs of wireless video users.
Second, I propose an adaptive video transmission algorithm to optimize the Overall Quality (OQ) of rate-switching videos, i.e., the viewers' judgement on the quality of the whole video. Through the subjective study, I find that the OQ is strongly correlated with the empirical cumulative distribution function (eCDF) of the video quality perceived by viewers. Based on this observation, I develop an adaptive video transmission algorithm that maximizes the number of video users who satisfy given constraints on the eCDF of perceived video qualities.
Third, I propose an adaptive transmission algorithm for scalable videos. Different from the rate-switching systems, scalable videos support rate adaptation for each video frame. The proposed adaptive transmission algorithm maximizes the time-averaged video quality while maintaining continuous video playback. When the channel throughput is high, the algorithm increases the video data rate to improve video quality. Otherwise, the algorithm decreases the video data rate to buffer more videos and to reduce the risk of playback interruption. Simulation results show that the performance of the proposed algorithm is close to a performance upper bound.<br>text
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Hung, Wei-Chih, and 洪暐智. "Iterative 3D-MRF based Decoder for Uncompressed Wireless Video Transmission." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/44759004587303643843.
Full textAbstract:
碩士<br>國立臺灣大學<br>電信工程學研究所<br>101<br>Due to the emergence of mmWave systems that provide multi-Gbps data rate over 60GHz band, uncompressed video transmission has been considered as a commonly used feature for wireless multimedia transmission over the wireless personal area networks (WPANs). However, mmWaves signals usually have higher attenuation than the conventional low-frequency wireless signals, and therefore supporting transmission in a low SNR condition becomes a challenging problem for such systems. In this thesis, we propose an iterative source-channel decoding method for uncompressed video transmission based on a proposed novel 3D-MRF model. The 3D-MRF model is a bit-plane level MRF model which successfully reveals the spatial and temporal redundancy of video sequences. For those video sequences of intense movement, we utilize the motion estimation at the decoder side to precisely locate the temporal movement under the block-base view, and thus the temporal redundancy can be fully used by the 3D-MRF. Through the 3D-MRF model, we develop the 3D-MRF based soft-in soft-out (SISO) source decoder. The 3D-MRF based SISO source decoder has much lower complexity than conventional iterative MAP-MRF decoder while still significantly improves the decoding performance. We design an iterative source-channel decoding structure which is capable of jointly estimating the MRF parameters at the receiver, and thus the proposed decoder can automatically adjust the amount of the information exchange according to the decoding video sequence. Also, by adding a single buffer into our decoder structure, the temporal extrinsic information is allowed to propagate throughout the video decoding process. We show that the proposed ISCD method can significantly enhance the video quality in terms of peak signal-to-noise ratio (PSNR). Even under very low SNR condition, the video frames are still maintained in good quality.
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Cheng, Chih-Hao, and 鄭志豪. "Video Transmission Quality Improvement Under Multi-Hop Wireless Network Architecture." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/31133502236276244688.
Full textAbstract:
碩士<br>國立金門大學<br>電子工程學系碩士班<br>101<br>As wireless local area networks have been widely deployed and smart devices are becoming common in human everyday life, the demanding for video applications, such as video conference, video on demand, and video games is still increasing. However, the bandwidth in wireless networks is limited and channel quality is varying. As a result, how to provide a better delivered video quality over wireless networks is challenging. Also, the current solutions to better video transmission are almost only considering single hop transmission. When those solutions are applied in multihop wireless networks, such as wireless mesh network or VANET, the delivered video quality may not be good as one hop transmission. Therefore, we propose a new mechanism to improve video transmission in multihop wireless networks. The new mechanism contains two methods. One is to privilege the packets that have already traversed more hops. The other is control the number of retransmission for video packets with different importance. Through NS2 simulations, the results show the effectiveness of proposed mechanism.
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Su, Yih-ching, and 蘇益慶. "Fine Granularity Video Compression Technique and Its Application to Robust Video Transmission over Wireless Internet." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/72729881018038725654.
Full textAbstract:
博士<br>國立中山大學<br>資訊工程學系研究所<br>92<br>This dissertation deals with (a) fine granularity video compression technique and (b) its application to robust video transmission over wireless Internet. First, two wavelet-domain motion estimation algorithms, HMRME (Half-pixel Multi-Resolution Motion Estimation) and HSDD (Hierarchical Sum of Double Difference Metric), have been proposed to give wavelet-based FGS (Fine Granularity Scalability) video encoder with either low-complexity or high-performance features. Second, a VLSI-friendly high-performance embedded coder ABEC (Array-Based Embedded Coder) has been built to encode motion compensation residue as bitstream with fine granularity scalability. Third, the analysis of loss-rate prediction over Gilbert channel with loss-rate feedback, and several optimal FEC (Forward Error Correction) assignment schemes applicable for any real-time FGS video transmission system will be presented in this dissertation.
In addition to those theoretical works mentioned above, for future study on embedded systems for wireless FGS video transmission, an initiative FPGA-based MPEG-4 video encoder has also been implemented in this work.