—This letter is concerned with a family of modified turbo-type codes, referred to as turbo-SPC (single parity check) codes. A technique based on the SPC code is introduced to replace puncturing for rate adjustment. A noticeable feature of the proposed scheme is the significantly reduced decoding complexity compared with the standard punctured turbo code. The cost reduction factor becomes more n...

In a recent paper, it is shown that if Pearl's belief propagation algorithm is applied to the Bayesian belief network of a turbo code, the turbo decoding algorithm immediately results. From this perspective, it is recognized that the turbo coding structure imposes unnecessary diierentiation on the parity checks and the turbo decoding algorithm speciies a seemingly arbitrary sequential activatio...

Turbo codes, introduced by Berrou, Glavieux and Thitimajshima in 1993 [1], are widely used codes that exhibit excellent empirical results, i.e., the decoding algorithm produces a codeword very quickly. While turbo codes are very popular, theoretical analysis of their performance has been unsupportive. Codewords have extremely small minimum distance, and no one has been able to prove that the de...

Turbo codes are a new class of forward error correcting codes that have proved to give a performance close to the channel capacity as proposed by C. Shannon. A turbo code encoder is formed by the parallel concatenation of two identical recursive convolutional encoders separated by an interleaver. The turbo code decoder utilizes two cascaded decoding blocks where each block in turn shares a prio...

This report presents information on modeling and implementation of turbo codes. Turbo coding is a very powerful error correction technique that has made a tremendous impact on channel coding in the last few years. It outperforms all previously known coding schemes by achieving near Shannon limit error correction using simple component codes and large interleavers. The use of turbo codes enhance...

This is a tutorial paper meant to introduce the reader to the new concept of turbo codes. This is a new and very powerful error correction technique which outperforms all previous known coding schemes. It can be used in any communication system where a significant power saving is required or the operating signal–to–noise ratio is very low. Deep space communications, mobile satellite/cellular co...

It is known that one of the essential building blocks of turbo codes is the interleaver and its design using random, semi-random (S-Random) and deterministic permutations. In this paper, two new types of turbo code interleavers, Enhanced Block S-Random (EBSR) interleaver is proposed. The design algorithm for the new interleaver is described in depth, and the simulation results are compared to t...