Turbo coding is a very powerful error correction technique that has made a tremendous impact on channel coding in the last few years. They are recommended for increased capacity at higher transmission rates due to their superior performance over conventional codes. Turbo codes use any one of the decoding algorithms, Maximum a posteriori Probability (log MAP), Soft Output Viterbi Algorithm (SOVA...

11, we present two methods for the constuction codes and in section 111, we describe the soft decoding algorithm and give some results of RS soft decoding. In section IV, we give the soft decision algorithm derived from the theoretical Log-Likelihood-Ratio and in section V we describe the iterative algorithm for decoding RS product codes. Section VI and VI1 are dedicated to simulation results o...

1962 Gallager invents low density parity-check LDPC codes 1112 and what is now known as the sum-product iterative decoding algorithm for a p osteriori probability APP decoding. 1981 Tanner founds the eld of codes on graphs, introducing the bipartite graphical model now widely popular referred to as a Tanner graph" and the decoding algorithm now called the min-sum" or max-product" algorithm. Tan...

Vol. 106 No. 9/10 Page 1 of 11 ABSTRACT Repeat-punctured turbo codes, an extension of the conventional turbo-coding scheme, has shown a significant increase in bit-error rate performance at moderate to high signal-to-noise ratios for short frame lengths. Superorthogonal convolutional turbo codes (SCTC) makes use of superorthogonal signals to improve the performance of the conventional turbo cod...

Digital fountain codes were originally packet-level forward erasure codes, but researchers have found that they are good at correcting bit errors. Modern LDPC and turbo codes have been shown to approach the Shannon limit. However, they are fixed rate codes and cannot well satisfy the Internet services that may encounter variable loss rates or asynchronous data access. For both packet and bit le...

The performance of a Turbo code with short block length depends critically on the interleaver design. There are two major criteria in the design of an interleaver: the distance spectrum of the code and the correlation between the information input data and the soft output of each decoder corresponding to its parity bits. This paper describes a new interleaver design for Turbo codes with short b...

Joseph H. Kang, Wayne E. Stark, and Alfred O. Hero Dept. of Electrical Engineering and Computer Science University of Michigan, Ann Arbor Abstract In this paper, turbo codes are investigated in fading and burst channels. In particular, we consider the design and performance of turbo codes for a GilbertElliot burst channel and in a realistic fading channel. For both cases, our approach is to com...

Recently, a coding scheme termed turbo-codes was proposed which achieves results very close to the Shannon-limit. The encoding and decoding of these codes is reviewed. We propose a method of estimating the variance which is necessary for turbo-code decoding. The performances of the turbo-code decoder, with a known channel variance, the conventional variance estimate , and our novel technique, a...

A novel method of estimating the BER performance of finite length turbo codes in a binary AWGN channel is proposed. We consider the asymptotes of BER performance at low and high Eb N0 resulted from the small and large extrinsic values, respectively. The BER performance curve transitions between two asymptotes in the waterfall region, where the transition probability is approximately obtained by...

Turbo codes occupy a special place in the field of wireless communications for their outstanding performances in correcting errors that appear on transmission channels. This paper analyzes the influence of trellis termination methods on turbo codes performances, over a channel affected by impulsive noise and Binary Phase-Shift Keying modulation. The statistical model used for the impulsive nois...