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This paper Compares various Error correcting codes in Nano scale Memory cells in terms of Belief Propagation Algorithm which is applied in a Markov Random Field (MRF). Soft error correction is critical for different Nano scale devices performing storage. As the Nano memories are with High fault rates, the conventional Error correcting Codes (ECCs) are not directly applicable. To achieve higher error...
Utilization of error-correction coding scheme in contemporary communication system enhances sufficient redundancy which in turn increases the immunity to deal with the channel impairments. Proper adjustment of interleaver size and iteration leads to considerable improvement in BER performance of Turbo code under AWGN channel condition. In this paper, an optimized Asymmetric Turbo code has been proposed...
In most practical communication systems where the source encoder is followed by the channel encoder, there is some mismatch between the length of the bits from the source encoder and that fed into the channel encoder. Therefore, dummy bits are usually padded to the source coded bits so as to fill the gap, and these padded bits are usually discarded after channel decoding at the receiver. In this paper,...
SOVA and log-MAP turbo decoding algorithms share common operations. Our analysis shows that the improved reconfigurable SOVA/log-MAP turbo decoder can be implemented in LTE systems for AWGN channel. We examine two data rates, and for each one we consider the nine possible QCIs using five frames. Considering BER and latency limitations for each QCI, SOVA is proposed for most of the cases for low data...
This paper proposes a new criterion to stop the iterations in turbo decoders, based on the minimization of the probability of erroneous decisions, hence the name MinPe. The criterion analyses the evolution of Log-Likelihood Ratio (LLR) and compares the distance between the distributions of the LLR's negative and positive values with a threshold depending on the average of positive LLR's values. The...
This paper proposes a low complexity joint source-channel coding (JSCC) technique that can well exploit two-dimensional (2D) source correlation using turbo single parity check (SPC) codes. Based on similar structure of the product accumulate code, a rate-1 inner code is serially concatenated to the turbo SPC code structure in order to overcome the high error floor issue of turbo SPC codes. The 2D...
A technique used for controlling the errors in data transmission over a noisy channel is known as Channel coding. Low Density Parity Check(LDPC) codes and also Turbo codes approaches Shannon capacity limit. In this paper, the performance of Quasi Cyclic(QC) LDPC codes and Random LDPC codes are compared in terms of error. The code which is appropriate for hardware implementation in terms of structural...
In this work, three thermal-aware kernel mappings are proposed for a three-dimensional multi-mode channel decoding architecture. The proposed kernel mappings can reduce the peak temperature and support different thermal and latency constraints. In our experiments, we show the peak temperature can be reduced from 16.2°C∼33.8°C. Besides, we also demonstrate that different mapping is chosen under different...
Today's need of wireless communication is undergoing astounding growth in day to day process. The quality of wireless communication must be enhanced with reduced cost. A coding system is required which can provide high data rate with error free communication and reduced area utilization. Among various error correcting codes, the turbo codes known as Parallel Convolutional Concatenated Code (PCCC)...
A study of the iterations stopping criteria adapted to multi-non-binary turbo-decoders, based on the evolution of a posteriori probability density (APP) is presented. The performaces bit / frame error rate (B/FER) versus signal to noise ratio (SNR) of multi-non-binary turbo codes (MNBTC) equipped with the iterations stopping mechanism proposed in this study are compared with those obtained using the...
Turbo codec in 3GPP LTE standard is implemented in an existing Rayleigh fading channel. Its bit error rate (BER) performance is gauged. The research is investigated to compare the performance of turbo codes with traditional Quadratic Permutation Polynomial (QPP) interleaver and comparatively simpler matrix interleaver in Rayleigh flat fading channel. The simulation outcome reveals that the BER performance...
Error correcting codes have always played a prominent role in the definition of secure and reliable space missions. Both telecommand (TC) and telemetry (TM) have benefited by the introduction of suitable co/decoding schemes, ranging from classic Bose-Chaudhuri-Hocquenghem, Reed-Solomon and convolutional codes to more recent state-of-the art codes based on soft-decision and iterative decoding. As a...
In order to support high data rate communications, the third generation partnership project (3GPP) long term evolution (LTE) implements multiple-input multiple-output (MIMO) systems. In addition, to achieve excellent performance, LTE also employs turbo codes as the forward error correcting (FEC) standard. Although conventional turbo codes give satisfactory performance in the ideal MIMO, significant...
In this paper, we give an overview of spatially coupled turbo codes (SC-TCs), the spatial coupling of parallel and serially concatenated convolutional codes, recently introduced by the authors. For presentation purposes, we focus on spatially coupled serially concatenated codes (SC-SCCs). We review the main principles of SC-TCs and discuss their exact density evolution (DE) analysis on the binary...
In the South China Sea, an underwater acoustic communication network (UWACN) is now in the experimental phase. The aim of UWACN project is to build a shallow water network which includes more than 10 nodes and continuously collects ocean observation real-time data with duration larger than one month. The design and implementation of robust and low power modem for the underwater network is considered...
In this paper, we present the results of using a turbo decoder to retrieve a serially encoded data stream, which has been transmitted over an aeronautical channel. The transmitted data streams are Double Differential Phase Shift Keying (DDPSK) modulated signals, which are encoded using two rate one-half (1/2) recursive systematic convolutional (RSC) encoders, and then transmitted over the channel...
In mobile communication systems such as LTE, Hybrid-ARQ (HARQ) schemes based on Turbo codes have proved to be very effective in ensuring reliable transmission. However, several modified HARQ and Turbo decoding strategies have been recently developed to further improve performance. This paper proposes an enhanced coding scheme for LTE which couples a modified Turbo coding strategy with Reliability...
In this paper, the performance of the Least Squares (LS) estimator along with turbo codes in OFDM is evaluated for the SUI channel models in the presence of AWGN. Turbo codes are used in this paper because of its BER performance close to Shannon limit. The iterative turbo decoder exchanges soft information between the component decoders. Maximum A Posteriori (MAP) and its simplified version Max-Log-MAP...
This paper treats the exploration of carrier (frequency/phase) synchronization methods for use in second generation of Digital Video Broadcasting — Return Channel via Satellite (DVB-RCS2). This new standard specifies reference bursts consisting of very limited number of known symbols and operation of turbo code decoder at extremely low Signal to Noise Ratio (SNR). The abovementioned constraints rule...
Long Term Evolution (LTE) is a paradigm for mobile communication providing high speed data. The LTE terms provide a framework for enlarged capacity, enhanced spectrum efficiency and coverage as well as condensed latency as compared to the second and third generation wireless networks. Six downlink channels are used by LTE of which three are data bearing channels and the rest are control channels....
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