Iterative decoding of two-dimensional systematic convolutional codes has been termed “turbo” (de)coding. Using log-likelihood algebra, we show that any decoder can he used which accepts soft inputs-including a priori values-and delivers soft outputs that can he split into three terms: the soft channel and a priori inputs, and the extrinsic value. The extrinsic value is used as an a priori value...

Concatenated Convolutional Codes Jung-Fu Cheng [email protected] Abstract Two classes of generalized concatenated (GC) codes with convolutional outer codes are studied. The rst class is based on the classical Plotkin ja bjbj construction. A new suboptimal multi-stage soft decision algorithm is proposed and the corresponding performance bounds are obtained. These codes are shown to achieve...

The class of convolutional codes generalizes the class of linear block codes in a natural way. The construction of convolutional codes which have a large free distance and which come with an e cient decoding algorithm is a major task. Contrary to the situation of linear block codes there exists only very few algebraic construction of convolutional codes. It is the purpose of this article to int...

In this paper we study periodically time-varying convolutional codes by means of input-state-output representations. Using these representations we investigate under which conditions a given time-invariant convolutional code can be transformed into an equivalent periodic time-varying one. The relation between these two classes of convolutional codes is studied for period 2. We illustrate the id...

A pragmatic approach for the construction of space-time codes over block fading channels is investigated. The approach consists in using common convolutional encoders and Viterbi decoders with suitable generators and rates, thus greatly simplifying the implementation of space-time codes. For the design of pragmatic space-time codes a methodology is proposed and applied, based on the extension o...

In this paper we introduce a new type of superregular matrices that give rise to novel constructions of two-dimensional (2D) convolutional codes with finite support. These codes are of rate 1/n and degree δ with n ≥ δ + 1 and achieve the maximum possible distance among all 2D convolutional codes with finite support with the same parameters.

Absfmcf-The paper describes the possible implementation of concatenated coding scheme suitable particularly for high date rate applications. The proposed coding scheme uses a set of n convolutional codes multiplexed into an inner code and a (n, n 1) single-parity-check code serving as the outer code. Each of the inner convolutional codes is decoded independently with maximum-likelihood decoding...

we present an approach to design of fault tolerant computing systems. in this paper, a technique is employed that enable the combination of several codes, in order to obtain flexibility in the design of error correcting codes. code combining techniques are very effective, which one of these codes are turbo codes. the algorithm-based fault tolerance techniques that to detect errors rely on the c...