Proceedings ArticleDOI
On the performance of turbo codes
C.C. Wang
- Vol. 3, pp 987-992
TLDR
In this article, the performance of the turbo code is sensitive to its code structure, which is made up of code rate, constraint length, tap connection, block size, interleaving pattern and number of decoding iterations.Abstract:
The performance of the turbo code is sensitive to its code structure, which is made up of code rate, constraint length, tap connection, block size, interleaving pattern and number of decoding iterations. In this paper, mitigation techniques that can lower the error floor are adopted in both encoder and decoder. Optimum tap connections are listed for codes with constraint lengths 3, 4, and 5. Performance variations achieved by changing different parameters are investigated. Simulation results show that (1) using 10 decoding iterations is adequate; (2) the S-random interleaving provides the best performance among the interleavers investigated; (3) using codes with constraint lengths greater than 3 does not buy any additional coding gain for short block size (in the vicinity of 100); (4) for block size greater than 500, no significant improvement is noticed by increasing the constraint length from 4 to 5 in the range of bit error rate (BER) <10/sup -6/; and (5) the punctured rate 1/2 code structure degrades the performance by only 0.5 to 0.7 dB in comparison with the classic rate 1/3 turbo code for constraint lengths 3, 4, and 5.read more
Citations
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Journal ArticleDOI
Design of parallel concatenated convolutional codes
Sergio Benedetto,Guido Montorsi +1 more
TL;DR: The separate contributions that the interleaver length and constituent codes give to the overall performance of the parallel concatenated code are characterized, and some guidelines for the optimal design of the constituent convolutional codes are presented.
Soft-Output Decoding Algorithms in Iterative Decoding of Turbo Codes
TL;DR: Two versions of a simplified maximum a posteriori decoding algorithm, which work in a sliding window form, like the Viterbi algorithm, and can thus be used to decode continuously transmitted sequences obtained by parallel concatenated codes, without requiring code trellis termination.
The Development of Turbo and LDPC Codes for Deep-Space Applications Error-correcting codes that allow very power-efficient information transmission from spacecraft have been developed along with suitable encoding and decoding hardware.
TL;DR: The development of error-correcting codes has been closely coupled with deep-space exploration since the early days of both. as mentioned in this paper describes the research, design, implementation and standardization work that has taken place at NASA's Jet Propulsion Laboratory (JPL) for both turbo and low-density parity-check (LDPC) codes.
Journal ArticleDOI
Adaptive turbo-coded modulation for flat-fading channels
TL;DR: This work determines the optimal adaptation strategy that maximizes the throughput of this turbo-coded system, while achieving a given bit-error rate under an average power constraint.
Patent
Turbo product code decoder
TL;DR: In this article, a turbo product code decoder for decoding multi-dimensional coding schemes is presented. But the decoder is configured for receiving soft decision values, and the soft difference values from each axis-iteration are then summed with the original soft decision value in decoding each of the other axis.
References
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Proceedings ArticleDOI
Near Shannon limit error-correcting coding and decoding: Turbo-codes. 1
TL;DR: In this article, a new class of convolutional codes called turbo-codes, whose performances in terms of bit error rate (BER) are close to the Shannon limit, is discussed.
Journal ArticleDOI
Unveiling turbo codes: some results on parallel concatenated coding schemes
Sergio Benedetto,Guido Montorsi +1 more
TL;DR: A method to evaluate an upper bound to the bit error probability of a parallel concatenated coding scheme averaged over all interleavers of a given length is proposed and used to shed some light on some crucial questions which have been floating around in the communications community since the proposal of turbo codes.
Proceedings ArticleDOI
Turbo codes for PCS applications
Dariush Divsalar,F. Pollara +1 more
TL;DR: A new simple method for trellis termination is described, the effect of interleaver choice on the weight distribution of the code, and the use of unequal rate component codes which yields better performance are introduced.
Proceedings ArticleDOI
Illuminating the structure of code and decoder of parallel concatenated recursive systematic (turbo) codes
TL;DR: It is shown that the associated iterative decoder can be formulated in a simpler fashion by passing information from one decoder to the next using log-likelihood ratios as opposed to channel values that need to be normalized for stable decoding.