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To date there is no practical means to evaluate the true word error probability (WEP) of a given turbo or LDPC code because typical decoders cannot achieve the performance of ML decoding. In this paper, we propose a viable methodology to establish tight bounds on the ML-decoding WEP for these codes through empirical simulation. Our framework centers on the efficient use of multiple-output decoding...
In this article, the authors present a new digital communication system combining a turbo code and modulation. Developed by a pragmatic approach. This combination based on the use of turbo-codes and the notion of binary encoding signal modulation considered minimizes the probability of bit error at the output of the channel (Gray coding). This system is not only relatively simple to implement, but...
The present paper proposes an early stopping method for iterative turbo decoding. Many criterions were proposed to date, motivated by a variety of reasons, such as increasing average decoding throughput or reducing average decoder power consumption. The method is devised on observing the behavior of LLR (Log-Likelihood Ratio). Simulation results in comparing the proposed method with some normalization...
This paper describes a review of turbo coding with channel estimation for Single-input and Single output system in ultra-wide band (SISO-UWB) channel. The common decoding algorithms used in turbo codes are Bahl, Cocke, Jelinek and Raviv (BCJR) algorithm, Viterbi algorithm, and Soft Output Viterbi Algorithm (SOVA). In the application of channel estimation with turbo codes the techniques used are maximum...
OFDM with Quadrature amplitude modulation (QAM) technique can be used for high speed optical applications. As the order of modulation increases, the bit error rate (BER) increases. Forward Error correction (FEC) coding like LDPC coding is generally used to Improve BER performance. LDPC provides large minimum distance and also the power efficiency of the LDPC code increases significantly with the code...
In the satellite communication system, Doppler spread is caused by the movement of the mobile receiver such as high speed aircraft, vessel, and so on. To overcome Doppler spread in the satellite communications, we propose the novel FDE (Frequency Domain Equalizer) and turbo code in order to compensate Doppler spread efficiently in this paper. And we adapt single carrier system in order to save power...
This paper presents a hybrid structured turbo code, which is composed by circular buffer rate matching (CBRM) and XOR coded parity compression (XCPC). A primary focus is on an ambiguity problem caused by punctured bits in CBRM. The CBRM is a straightforward approach to control coding rate to desired one with sacrificing deficiency of parity bits. In order to remedy the deficiency/ambiguity problem,...
In this paper turbo multi-user detection (MUD) technique is proposed for multi carrier code division multiple access (MC-CDMA) system to overcome the affects of multiple access interference (MAI) caused by the inter-cell and intra-cell interference and near far effect. The proposed technique estimates the interference from the unknown users and the interference estimate is subtracted from the received...
Turbo codes are employed in many robust wireless digital communication systems. Those codes have been adopted for the satellite return channel in DVB-RCS standards. The implementation for such codes is complex and dissipates a large amount of power. For decoder hardware implementation, reduced complexity leads to low power consumption which is considered a key implementation issue. This paper investigates...
Rate-compatible turbo codes are designed using dithered relative prime (DRP) interleavers with data puncturing. DRP interleavers are simple to implement and memory-efficient. Their repetitive structure facilitates finding interleaver parameters that provide excellent performance at both high and low error rates. With puncture-constrained DRP interleavers, the data and parity puncture patterns can...
Future radio technologies are expected to deliver ever higher bit rates and a wider range of data applications to an increasing number of subscribers. Flexible and high performance unequal error protection techniques are necessary for better application level perceived quality with lower data rates. In this paper, we present a new generalized mechanism for enhanced usage of available spectral resources...
Cognitive radio (CR) technology represents a promising solution for solving the problem of spectrum scarcity and underutilization in wireless communications. While orthogonal frequency division multiplexing (OFDM) is regarded as a suitable technology for the CR physical layer, it can suffer from out-of-band radiation, which hinders its spectrum sharing capabilities. In this paper we consider a turbo-coded...
Wireless Sensor Networks are to a large extent characterized by the sensing, communication and computation constraints of their constituent sensor nodes. Moreover, energy efficient operation is critical, since the nodes are typically powered by batteries or scavenge energy from their environment. Communication over a wireless channel is prone to noise and interference, which causes errors to occur...
Iterative receiver is poised to become the most prevalent receiver technology in near future. The paper explains the designing methodology of iterative receiver from graph theoretic approach. Modeling of well known turbo convolution code in factor graph framework with Sum-Product-Algorithm (SPA) has been discussed here. The model shows simpler representation of complex encoder trellis. Exchange of...
In this paper a VLSI architecture for a configurable turbo decoder, compliant with the 3GPP2 standard is presented. A simple modification of the conventional iterative structure of a turbo decoder is presented, where one of the constituent interleavers can be eliminated, allowing an important reduction in the overall complexity of the turbo decoder with no performance degradations. Performance analysis...
It is well known in information theory that superposition coding is an optimal technique for providing a single transmission that both provides a high data rate when channel conditions are good and still provides some information when the channel conditions are poor (perhaps due to jamming). Typical superposition coding schemes for the additive white Gaussian noise channel combine signals after the...
Terrestrial Trunked Radio (TETRA) is a digital trunked mobile radio standard developed by the European Telecommunications Standards Institute (ETSI). Especially, TETRA Release 2 supports different channel bandwidths and modulation techniques, and turbo code has been adopted as a channel code with powerful error correcting capability. In this paper, we present the dedicated hardware interleaver for...
Soft based linear block codes combined with linear modulation cannot obtain the coding gains by increasing iterations. In this paper, we propose rate-compatible turbo product codes with extended BCH codes by zero padding and shortening the row and/or column to adapt next generation (NG) DVB-RCS system. And also, in order to make various coding rates required on standard, we used different coding rates...
We construct here a new family of quantum codes related to serial turbo-codes which are excellent error-reducing codes under iterative decoding for very large channel noise values. Moreover we also show that this family of codes has unbounded minimum distance.
Turbo product codes (TPC) are very suitable for applications requiring a large code length, a high code-rate, and good error performance. In the Chase decoding algorithm, normally a few least reliable positions are selected and the test sequences are generated from these positions. This paper proposes two methods to lower the complexity of the Chase-Pyndiah decoding algorithm. The first scheme reduces...
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