1,905 research outputs found
Expanding window fountain codes for unequal error protection
A novel approach to provide unequal error protection (UEP) using rateless codes over erasure channels, named Expanding Window Fountain (EWF) codes, is developed and discussed. EWF codes use a windowing technique rather than a weighted (non-uniform) selection of input symbols to achieve UEP property. The windowing approach introduces additional parameters in the UEP rateless code design, making it more general and flexible than the weighted approach. Furthermore, the windowing approach provides better performance of UEP scheme, which is confirmed both theoretically and experimentally. © 2009 IEEE
Expanding window fountain codes for unequal error protection
A novel approach to provide unequal error protection (UEP) using rateless codes over erasure channels, named Expanding Window Fountain (EWF) codes, is developed and discussed. EWF codes use a windowing technique rather than a weighted (non-uniform) selection of input symbols to achieve UEP property. The windowing approach introduces additional parameters in the UEP rateless code design, making it more general and flexible than the weighted approach. Furthermore, the windowing approach provides better performance of UEP scheme, which is confirmed both theoretically and experimentally. © 2009 IEEE
Expanding window fountain codes for unequal error protection
A novel approach to provide unequal error protection (UEP) using rateless codes over erasure channels, named Expanding Window Fountain (EWF) codes, is developed and discussed. EWF codes use a windowing technique rather than a weighted (non-uniform) selection of input symbols to achieve UEP property. The windowing approach introduces additional parameters in the UEP rateless code design, making it more general and flexible than the weighted approach. Furthermore, the windowing approach provides better performance of UEP scheme, which is confirmed both theoretically and experimentally
Application layer systematic network coding for sliced H.264/AVC video streaming
Application Layer Forward Error Correction (AL-FEC) with rateless codes can be applied to protect the video data over lossy channels. Expanding Window Random Linear Codes (EW RLCs) are a flexible unequal error protection fountain coding scheme which can provide prioritized data transmission. In this paper, we propose a system that exploits systematic EW RLC for H.264/Advanced Video Coding (AVC) slice-partitioned data. The system prioritizes slices based on their PSNR contribution to reconstruction as well as temporal significance. Simulation results demonstrate usefulness of using relative slice priority with systematic codes for multimedia broadcast applications
Decentralised distributed fountain coding: asymptotic analysis and design
A class of generic decentralised distributed fountain coding schemes is introduced and the tools of analysis of the performance of such schemes are presented. It is demonstrated that the developed approach can be used to formulate a robust code design methodology in a number of instances. We show that two non-standard applications of fountain codes, fountain codes for distributed source coding and fountain codes for unequal error protection lie within this decentralised distributed fountain coding framework
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
Rateless Codes with Progressive Recovery for Layered Multimedia Delivery
This paper proposes a novel approach, based on unequal error protection, to
enhance rateless codes with progressive recovery for layered multimedia
delivery. With a parallel encoding structure, the proposed Progressive Rateless
codes (PRC) assign unequal redundancy to each layer in accordance with their
importance. Each output symbol contains information from all layers, and thus
the stream layers can be recovered progressively at the expected received
ratios of output symbols. Furthermore, the dependency between layers is
naturally considered. The performance of the PRC is evaluated and compared with
some related UEP approaches. Results show that our PRC approach provides better
recovery performance with lower overhead both theoretically and numerically
Coded Slotted ALOHA with Varying Packet Loss Rate across Users
The recent research has established an analogy between successive
interference cancellation in slotted ALOHA framework and iterative
belief-propagation erasure-decoding, which has opened the possibility to
enhance random access protocols by utilizing theory and tools of
erasure-correcting codes. In this paper we present a generalization of the
and-or tree evaluation, adapted for the asymptotic analysis of the slotted
ALOHA-based random-access protocols, for the case when the contending users
experience different channel conditions, resulting in packet loss probability
that varies across users. We apply the analysis to the example of frameless
ALOHA, where users contend on a slot basis. We present results regarding the
optimal access probabilities and contention period lengths, such that the
throughput and probability of user resolution are maximized.Comment: 4 pages, submitted to GlobalSIP 201
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