Sun, 27 Jul 2008 07:49:14 BST CiteULike: dcastro's block http://www.citeulike.org/user/dcastro/tag/block CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dcastro/article/2972728 <i>Electronics Letters, Vol. 32, No. 10. (1996), pp. 887-888.</i><br /><br />Parallel concatenated coding schemes employing convolutional codes as constituent codes linked by an interleaver have been proposed in the literature as `turbo codes'. They yield very good performance in connection with simple suboptimum decoding algorithms. The authors propose an alternative scheme consisting in the serial concatenation of block or convolutional codes and evaluate its average performance in terms of bit error probability Serial concatenation of block and convolutional codes S Benedetto G Montorsi Electronics Letters, Vol. 32, No. 10. (1996), pp. 887-888. 2008-07-08T14:27:40-00:00 1996 Electronics Letters 32 10 887 888 block code concatenation convolutional http://www.citeulike.org/user/dcastro/article/2802244 <i>Information Theory, IEEE Transactions on, Vol. 46, No. 1. (2000), pp. 189-205.</i><br /><br />This work considers the achievable performance for coded systems adapted to a multipath block-fading channel model. This is a particularly useful model for analyzing mobile-radio systems which employ techniques such as slow frequency-hopping under stringent time-delay or bandwidth constraints for slowly time-varying channels. In such systems, coded information is transmitted over a small number of fading channels in order to achieve diversity. Bounds on the achievable performance due to coding are derived using information-theoretic techniques. It is shown that high diversity can be achieved using relatively simple codes as long as very high spectral efficiency is not required. Examples of simple block codes and carefully chosen trellis codes are given which yield, in some cases, performances approaching the information-theoretic bounds On coding for block fading channels R Knopp PA Humblet doi:10.1109/18.817517 Information Theory, IEEE Transactions on, Vol. 46, No. 1. (2000), pp. 189-205. 2008-05-15T17:57:09-00:00 2000 Information Theory, IEEE Transactions on 46 1 189 205 block channel coding fading http://www.citeulike.org/user/dcastro/article/2674797 <i>Communications, IEEE Transactions on, Vol. 46, No. 8. (1998), pp. 1003-1010.</i><br /><br />This paper describes an iterative decoding algorithm for any product code built using linear block codes. It is based on soft-input/soft-output decoders for decoding the component codes so that near-optimum performance is obtained at each iteration. This soft-input/soft-output decoder is a Chase decoder which delivers soft outputs instead of binary decisions. The soft output of the decoder is an estimation of the log-likelihood ratio (LLR) of the binary decisions given by the Chase decoder. The theoretical justifications of this algorithm are developed and the method used for computing the soft output is fully described. The iterative decoding of product codes is also known as the block turbo code (BTC) because the concept is quite similar to turbo codes based on iterative decoding of concatenated recursive convolutional codes. The performance of different Bose-Chaudhuri-Hocquenghem (BCH)-BTCs are given for the Gaussian and the Rayleigh channel. Performance on the Gaussian channel indicates that data transmission at 0.8 dB of Shannon's limit or more than 98% (R/C>0.98) of channel capacity can be achieved with high-code-rate BTC using only four iterations. For the Rayleigh channel, the slope of the bit-error rate (BER) curve is as steep as for the Gaussian channel without using channel state information Near-optimum decoding of product codes: block turbo codes RM Pyndiah doi:10.1109/26.705396 Communications, IEEE Transactions on, Vol. 46, No. 8. (1998), pp. 1003-1010. 2008-04-15T18:17:48-00:00 1998 Communications, IEEE Transactions on 46 8 1003 1010 block decoder turbocode http://www.citeulike.org/user/dcastro/article/2648776 <i>Wireless Communications, IEEE Transactions on, Vol. 1, No. 2. (2002), pp. 266-273.</i><br /><br />Turbo equalizers have been shown to be successful in mitigating the effects of inter-symbol interference introduced by partial response modems and by dispersive channels for code rates of R&les; 1/2. We comparatively studied the performance of a range of binary phase-shift keying turbo equalizers employing block-turbo codes, namely Bose-Chaudhuri-Hocquenghen (1960, 1959) turbo codes, convolutional codes, and convolutional turbo codes having high code rates, such as R=3/4 and R=5/6, over a dispersive five-path Gaussian channel and an equally weighted symbol-spaced five-path Rayleigh fading channel. These turbo equalization schemes were combined with an iterative channel estimation scheme in order to characterize a realistic scenario. The simulation results demonstrated that the turbo-equalized system using convolutional turbo codes was the most robust system for all code rates investigated Comparative study of turbo equalization schemes using convolutional, convolutional turbo, and block-turbo codes Bee Yeap Tong Liew J Hamorsky L Hanzo doi:10.1109/7693.994820 Wireless Communications, IEEE Transactions on, Vol. 1, No. 2. (2002), pp. 266-273. 2008-04-10T09:41:29-00:00 2002 Wireless Communications, IEEE Transactions on 1 2 266 273 block code convolutional equalization turbocode http://www.citeulike.org/user/dcastro/article/2067690 <i>Signal Processing, Vol. 86, No. 2. (February 2006), pp. 273-278.</i><br /><br />We present a parallel version of Viterbi's decoding procedure, for which we are able to demonstrate that the resultant task graph has restricted complexity in that the number of communications to or from any processor cannot exceed four for BCH codes. The resulting algorithm works in lock step making it suitable for implementation on a systolic processor array, which we have implemented on a field programmable gate array and have demonstrated the perfect scaling of the algorithm for two exemplar BCH codes. The parallelisation strategy is applicable to all cyclic codes and convolution codes. We also present a novel method for generating the state transition diagrams for these codes. A parallel Viterbi decoder for block cyclic and convolution codes JS Reeve K Amarasinghe doi:10.1016/j.sigpro.2005.05.016 Signal Processing, Vol. 86, No. 2. (February 2006), pp. 273-278. 2007-12-06T16:56:24-00:00 2006 Signal Processing 86 2 273 278 block code convolutional cyclic decoder viterbi