Previous research into MIMO systems has focused little on optimisation for video transmission. In terms of multimedia transmission, spatial multiplexing (SM) is commonly proposed as the most suitable MIMO technique. M...
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ISBN:
(纸本)9781424414369
Previous research into MIMO systems has focused little on optimisation for video transmission. In terms of multimedia transmission, spatial multiplexing (SM) is commonly proposed as the most suitable MIMO technique. Most SM-based video transport schemes look to exploit the multiplexing gain, which comes at the expense of a relatively high SNR, unless the channel state is known at the transmitter. Space-time block coding (STBC) is an attractive technique that does not provide the mapping flexibility of SM techniques, but does dramatically reduce the packet-error rate. This paper compares these techniques in terms of decoded video quality through simulations based on practical transmission scenarios. The use of multiple-description coding (MDC) is further proposed to provide a new class of wireless video transmission algorithms.
Much of the work on wireless transmission over the past several years has focused on simulation and deployment of multiple-input-multiple-output (MIMO) systems. These systems provide benefits of improved robustness an...
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ISBN:
(纸本)9781424400621
Much of the work on wireless transmission over the past several years has focused on simulation and deployment of multiple-input-multiple-output (MIMO) systems. These systems provide benefits of improved robustness and enhanced throughput at relatively low cost. Despite the increased understanding of the performance of MIMO systems, little is known about which combination of channel and source coding yields the best results for video transport. It is clear that new ways of providing error-resilience that emerge from MIMO architectures need to be developed which can cope with the particularities of video content. This paper proposes a new scheme for video transmission using multiple-description coding (MDC). Two complementary MIMO techniques, space-time block coding (STBC) and spatial multiplexing (SM), are employed. The quality of the reconstructed video, already enhanced by the inherent MIMO systems' properties, is further improved through the use of MDC.
The most recent literature indicates Multiple Description (MD) as a new coding approach to handle the problem of video transmission over unreliable networks. This technique describes the source information in equally ...
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ISBN:
(纸本)0819448222
The most recent literature indicates Multiple Description (MD) as a new coding approach to handle the problem of video transmission over unreliable networks. This technique describes the source information in equally important and independent streams named multiple descriptions, by introducing some kind of redundancy into each description. Recent works have shown the success of using motion compensation prediction also in an MD videocoding scheme. Even though these MD systems have proved to be robust in an error-prone environment, they are in practice forced to use only two descriptions. This is a very strong constraint when more than two levels of reconstruction are required. For this reason this paper proposes two architectures of MD video coders;the first, that we call DC-MDVC, is based on the classical MD video codec architecture and the principle contribution is the use of a new MD algorithm based on a polyphase down-sampling technique. Since this architecture is suitable only in case of two descriptions, then a second architecture, called IF-MDVC, is given, where multi-level scalability is introduced by generating the multiple descriptions before the prediction loop. Results show that both architectures are appealing, and the second architecture seems to perform impressively well.
Promising performance of multiple-description coding (MDC) as a suitable video decomposition for MIMO (multiple-input-multiple-output) wireless transmission, reported previously by a number of authors, is further enha...
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ISBN:
(纸本)9781424417650
Promising performance of multiple-description coding (MDC) as a suitable video decomposition for MIMO (multiple-input-multiple-output) wireless transmission, reported previously by a number of authors, is further enhanced in this paper by investigating power allocation in MIMO systems that employ singular value decomposition (SVD). Inspired by the water-filling power allocation strategy, results demonstrate that further improvements over conventional, single-description coding (SDC) are possible if, for low SNRs, stronger sub-channel is boosted at the expense of the weaker channel. For high SNR values, the converse is true. A simple yet effective power allocation strategy whereby the bulk of the transmit power-the highest value considered was nine tenths-was allocated to the stronger channel (weaker channel) for very low (very high) SNRs yielded improvements of up to 4dB (1dB) in average MDC PSNR over the nominal-equal power allocation-case. The PSNR gains for low SNR values even exceeded the gains arising from water-filling.
H.264/AVC is expected to become an essential component in the delivery of wireless multimedia content. While achieving high compression ratios, this codec is extremely vulnerable to transmission errors. These errors g...
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ISBN:
(纸本)9781424416875
H.264/AVC is expected to become an essential component in the delivery of wireless multimedia content. While achieving high compression ratios, this codec is extremely vulnerable to transmission errors. These errors generally result in spatio-temporal propagation of distorted macroblocks (MBs) which significantly degrade the perceptual quality of the reconstructed video sequences. This paper presents a scheme for resilient transmission of H.264/AVC streams in noisy environments. The proposed algorithm exploits the redundant information which is inherent in the neighboring MBs and applies a Probabilistic Neural Network (PNN) classifier to detect visually impaired MBs. This algorithm achieves Peak Signal-to-Noise Ratio (PSNR) gains of up to 14.29 dB when compared to the standard decoder. Moreover, this significant gain in quality is achieved with minimal overheads and no additional bandwidth requirement, thus making it suitable for conversational and multicast/broadcast services where feedback-based transport protocols cannot be applied.
In this paper, we study the impact of spatio-temporal variations of a video sequence on wireless MIMO video transmission. In the light of our findings, we propose a cross-layer MIMO video communication architecture fo...
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ISBN:
(纸本)9781612842332
In this paper, we study the impact of spatio-temporal variations of a video sequence on wireless MIMO video transmission. In the light of our findings, we propose a cross-layer MIMO video communication architecture for efficient multimedia communication. Existing methods complement Spatial Multiplexing (SM) and Space Time Block coding (STBC) with enhanced source and channel coding strategies to improve video PSNR at a MIMO receiver. However, these methods ignore the adverse impacts of spatio-temporal content variations on video quality and decoding complexity. We show that the decision to switch between SM and STBC for effective video communication must be based on both channel conditions and motion intensity of a video. We quantify a video's spatio-temporal characteristics using a motion intensity measure, and propose a simple motion-adaptive MIMO video communication technique which can judiciously switch between SM and STBC configurations. Experimental evaluations show that the proposed technique provides significantly better video quality while having very low decoding complexity at the receiver. Based on this technique, we propose a novel cross-layer motion-adaptive architecture for wireless video communication.
作者：
Han, KJSuter, BWUSAF
Ctr Integrated Transmiss & Exploitat Res Lab Informat Directorate Rome NY 13441 USA
A great deal of digital video quality measurement research has been performed to quantify human visual perception with compressed video clips. Since transmitted video quality is heavily dependent on the bit-rate, erro...
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ISBN:
(纸本)0819449687
A great deal of digital video quality measurement research has been performed to quantify human visual perception with compressed video clips. Since transmitted video quality is heavily dependent on the bit-rate, error rate and dropped packet rate, a new measurement paradigm is required to analyze the corrupted video. Fast eigen-based video quality metric (VQM) and visualization techniques have been developed to measure and analyze the corrupted video qualities objectively. 3-D SPIHT and MPEG-2 with for-ward error correction (FEC) had been tested over a video CODEC RF Test-bed. The experimental results indicate that the proposed scheme is useful for a low complexity VQM.
H.264/AVC is expected to become an essential component in the delivery of wireless multimedia content. While achieving high compression ratios, this codec is extremely vulnerable to transmission errors. These errors g...
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H.264/AVC is expected to become an essential component in the delivery of wireless multimedia content. While achieving high compression ratios, this codec is extremely vulnerable to transmission errors. These errors generally result in spatio-temporal propagation of distorted macroblocks (MBs) which significantly degrade the perceptual quality of the reconstructed video sequences. This paper presents a scheme for resilient transmission of H.264/AVC streams in noisy environments. The proposed algorithm exploits the redundant information which is inherent in the neighboring MBs and applies a Probabilistic Neural Network (PNN) classifier to detect visually impaired MBs. This algorithm achieves Peak Signal-to-Noise Ratio (PSNR) gains of up to 14.29 dB when compared to the standard decoder. Moreover, this significant gain in quality is achieved with minimal overheads and no additional bandwidth requirement, thus making it suitable for conversational and multicast/broadcast services where feedback-based transport protocols cannot be applied.
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