In digital communication system error correction codes are used when channel is noisy. An error correction code removes errors induced in communication and make possible error free transmission. By use of such error correction code we can send signal at lower transmit power as compared to un-coded system. Convolutional code corrects both type of errors random and burst and used in deep space an...

High rate binary coset codes are investigated. The binary coset(BC) code is a binary convolutional code with parallel path. In our previous research of concatenated trelliscoded modulation(TCM) scheme, we have found that the e ective minimum distance of inner code is more important than the minimum free distance when TCM is used as inner code. In this paper, for inner code, we construct the hig...

via time slices which involve only nine information symbols, viz. u t ; u t01 ; 1 1 1 ; u t08. From the time slices for the phases that are multiples of 4 it follows that information symbol u t08 does not contribute to the corresponding output. This information symbol does not contribute to the outputs in the following time instants either; hence, we do not have to store it! Thus the Kötter–Var...

It is well known that a convolutional code is essentially a linear system def ined over a finite field. In this paper we elaborate on this connect ion. W e will def ine a convolutional code as the dual of a complete linear behavior in the sense of W illems. Using ideas from systems theory, we descr ibe a set of general ized first-order descriptions for convolutional codes. As an application of ...

In this paper, simulation model of OFDM based WIMAX system has been developed using punctured convolutional codes. The bit error rate performance of fixedWIMAX has been carried out for different modulation techniques like BPSK, QPSK, and QAM16 with different code rates 1/2, 2/3, 3/4 in each case of modulation technique. Puncturing is the process of deleting some parity bits from the code-word a...

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...

An important class of codes widely used in applications is the class of convolutional codes. Most of the literature of convolutional codes is devoted to convolutional codes over finite fields. The extension of the concept of convolutional codes from finite fields to finite rings have attracted much attention in recent years due to fact that they are the most appropriate codes for phase modulati...

It is shown that any rate lib systematic convolutional code over GF(p) can be decoded up to its minimum distance with respect to the decoding constraint length by a one-step threshold decoder. It is further shown that this decoding method can be generalized in a natural way to allow "decoding" of a received sequence in its unquantized analog form.

For rate R = 1=2 convolutional codes with 16 states there exists a gap between Heller’s upper bound on the free distance and its optimal value. This correspondence reports on the construction of 16state, binary, rate R = 2=4 nonlinear trellis and convolutional codes having dfree = 8; a free distance that meets the Heller upper bound. The nonlinear trellis code is constructed from a 16-state, ra...

Instead of a random interleaver, an algebraic interleaver interconnecting two simple convolutional codes with feedback encoders forms an algebraic quasi-cyclic code. An (nC , k) convolutional code in tailbiting form becomes a quasi-cyclic (QC) linear code of length LnC for some L = Mn. Interleavers with a period M connect two such codes to produce a QC turbo code. The QC turbo codes check equat...