23,087 research outputs found
Serially Concatenated Luby Transform Coding and Bit-Interleaved Coded Modulation Using Iterative Decoding for the Wireless Internet
In Bit-Interleaved Coded Modulation (BICM) the coding and modulation schemes were jointly optimized for the sake of attaining the best possible performance when communicating over fading wireless communication channels. The iterative decoding scheme of BICM (BICM-ID) invoking an appropriate bit-to-symbol mapping strategy enhances its achievable performance in both AWGN and Rayleigh channels. BICM-ID may be conveniently combined with Luby Transform (LT) codes, which were designed for handling packetized wireless Internet data traffic in erasure channels without retransmitting the corrupted packets. By jointly designing a serially concatenated LT-BICM-ID code, an infinitesimally low Bit Error Rate (BER) is achieved for Signal to Noise Ratios (SNR) in excess of 7.5dB over wireless Internet type erasure channels contaminated by AWGN
AONT-LT: a Data Protection Scheme for Cloud and Cooperative Storage Systems
We propose a variant of the well-known AONT-RS scheme for dispersed storage
systems. The novelty consists in replacing the Reed-Solomon code with rateless
Luby transform codes. The resulting system, named AONT-LT, is able to improve
the performance by dispersing the data over an arbitrarily large number of
storage nodes while ensuring limited complexity. The proposed solution is
particularly suitable in the case of cooperative storage systems. It is shown
that while the AONT-RS scheme requires the adoption of fragmentation for
achieving widespread distribution, thus penalizing the performance, the new
AONT-LT scheme can exploit variable length codes which allow to achieve very
good performance and scalability.Comment: 6 pages, 8 figures, to be presented at the 2014 High Performance
Computing & Simulation Conference (HPCS 2014) - Workshop on Security, Privacy
and Performance in Cloud Computin
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
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