900 research outputs found
Self-concatenated code design and its application in power-efficient cooperative communications
In this tutorial, we have focused on the design of binary self-concatenated coding schemes with the help of EXtrinsic Information Transfer (EXIT) charts and Union bound analysis. The design methodology of future iteratively decoded self-concatenated aided cooperative communication schemes is presented. In doing so, we will identify the most important milestones in the area of channel coding, concatenated coding schemes and cooperative communication systems till date and suggest future research directions
The Error-Pattern-Correcting Turbo Equalizer
The error-pattern correcting code (EPCC) is incorporated in the design of a
turbo equalizer (TE) with aim to correct dominant error events of the
inter-symbol interference (ISI) channel at the output of its matching Viterbi
detector. By targeting the low Hamming-weight interleaved errors of the outer
convolutional code, which are responsible for low Euclidean-weight errors in
the Viterbi trellis, the turbo equalizer with an error-pattern correcting code
(TE-EPCC) exhibits a much lower bit-error rate (BER) floor compared to the
conventional non-precoded TE, especially for high rate applications. A
maximum-likelihood upper bound is developed on the BER floor of the TE-EPCC for
a generalized two-tap ISI channel, in order to study TE-EPCC's signal-to-noise
ratio (SNR) gain for various channel conditions and design parameters. In
addition, the SNR gain of the TE-EPCC relative to an existing precoded TE is
compared to demonstrate the present TE's superiority for short interleaver
lengths and high coding rates.Comment: This work has been submitted to the special issue of the IEEE
Transactions on Information Theory titled: "Facets of Coding Theory: from
Algorithms to Networks". This work was supported in part by the NSF
Theoretical Foundation Grant 0728676
Turbo Decoding and Detection for Wireless Applications
A historical perspective of turbo coding and turbo transceivers inspired by the generic turbo principles is provided, as it evolved from Shannon’s visionary predictions. More specifically, we commence by discussing the turbo principles, which have been shown to be capable of performing close to Shannon’s capacity limit. We continue by reviewing the classic maximum a posteriori probability decoder. These discussions are followed by studying the effect of a range of system parameters in a systematic fashion, in order to gauge their performance ramifications. In the second part of this treatise, we focus our attention on the family of iterative receivers designed for wireless communication systems, which were partly inspired by the invention of turbo codes. More specifically, the family of iteratively detected joint coding and modulation schemes, turbo equalization, concatenated spacetime and channel coding arrangements, as well as multi-user detection and three-stage multimedia systems are highlighted
On chip interconnects for multiprocessor turbo decoding architectures
International audienc
Blind identification of an unknown interleaved convolutional code
We give here an efficient method to reconstruct the block interleaver and
recover the convolutional code when several noisy interleaved codewords are
given. We reconstruct the block interleaver without assumption on its
structure. By running some experimental tests we show the efficiency of this
method even with moderate noise
A Differential Turbo Detection Aided Sphere Packing Modulated Space-Time Coding Scheme
A signal construction method that combines orthogonal design with sphere packing has recently shown useful performance improvements over the conventional orthogonal design. In this contribution, we extend this concept and propose a novel Sphere Packing (SP) modulated differential Space-Time Block Coded (DSTBC) scheme, referred to here as (DSTBC-SP), which shows performance advantages over conventional DSTBC schemes. We also demonstrate that the performance of DSTBC-SP systems can be further improved by concatenating sphere packing aided modulation with channel coding and performing SP-symbol-to bit demapping as well as channel decoding iteratively. We also investigate the convergence behaviour of this concatenated scheme with the aid of Extrinsic Information Transfer (EXIT) Charts. The proposed turbo-detected DSTBC-SP scheme exhibits a ’turbo-cliff’ at Eb/N0 = 6dB and provides Eb/N0 gains of 23.7dB and 1.7dB at a BER of 10?5 over an equivalent-throughput uncoded DSTBC-SP scheme and a turbo-detected QPSK modulated DSTBC scheme, respectively
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