1,655 research outputs found
Unequal Error Protected JPEG 2000 Broadcast Scheme with Progressive Fountain Codes
This paper proposes a novel scheme, based on progressive fountain codes, for
broadcasting JPEG 2000 multimedia. In such a broadcast scheme, progressive
resolution levels of images/video have been unequally protected when
transmitted using the proposed progressive fountain codes. With progressive
fountain codes applied in the broadcast scheme, the resolutions of images (JPEG
2000) or videos (MJPEG 2000) received by different users can be automatically
adaptive to their channel qualities, i.e. the users with good channel qualities
are possible to receive the high resolution images/vedio while the users with
bad channel qualities may receive low resolution images/vedio. Finally, the
performance of the proposed scheme is evaluated with the MJPEG 2000 broadcast
prototype
Multi-user video streaming using unequal error protection network coding in wireless networks
In this paper, we investigate a multi-user video streaming system applying unequal error protection (UEP) network coding (NC) for simultaneous real-time exchange of scalable video streams among multiple users. We focus on a simple wireless scenario where users exchange encoded data packets over a common central network node (e.g., a base station or an access point) that aims to capture the fundamental system behaviour. Our goal is to present analytical tools that provide both the decoding probability analysis and the expected delay guarantees for different importance layers of scalable video streams. Using the proposed tools, we offer a simple framework for design and analysis of UEP NC based multi-user video streaming systems and provide examples of system design for video conferencing scenario in broadband wireless cellular networks
Buffer-Based Distributed LT Codes
We focus on the design of distributed Luby transform (DLT) codes for erasure
networks with multiple sources and multiple relays, communicating to a single
destination. The erasure-floor performance of DLT codes improves with the
maximum degree of the relay-degree distribution. However, for conventional DLT
codes, the maximum degree is upper-bounded by the number of sources. An
additional constraint is that the sources are required to have the same
information block length. We introduce a -bit buffer for each source-relay
link, which allows the relay to select multiple encoded bits from the same
source for the relay-encoding process; thus, the number of sources no longer
limits the maximum degree at the relay. Furthermore, the introduction of
buffers facilitates the use of different information block sizes across
sources. Based on density evolution we develop an asymptotic analytical
framework for optimization of the relay-degree distribution. We further
integrate techniques for unequal erasure protection into the optimization
framework. The proposed codes are considered for both lossless and lossy
source-relay links. Numerical examples show that there is no loss in erasure
performance for transmission over lossy source-relay links as compared to
lossless links. Additional delays, however, may occur. The design framework and
our contributions are demonstrated by a number of illustrative examples,
showing the improvements obtained by the proposed buffer-based DLT codes.Comment: 14 pages, 17 figures, submitte
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